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Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop (1997)

Chapter: APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS

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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Appendix C Papers Submitted By Opening Session Presenters

Contents

Remarks on Reducing Space Science Mission Costs, 23

Eberhardt Rechtin, University of Southern California

Perspectives on Small Spacecraft: Results of a Recent RAND Workshop, 30

Liam P. Sarsfield, RAND Critical Technologies Institute

Influence of Technology on Space Mission Costs, 42

Frank J. Redd, Utah State University

Summary of Techniques for Reducing Space Mission Costs, 48

Wiley J. Larson, International Space University and U.S. Air Force Academy

Mars Exploration Program Strategy: 1995-2020, 53

Donna L. Shirley and Daniel J. McCleese, NASA Jet Propulsion Laboratory

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Remarks On Reducing Space Science Mission Costs

Eberhardt Rechtin

University of Southern California

Introduction

These remarks have two objectives. The first is to highlight the areas of greatest opportunity for cost reduction. To do that, I will need to distinguish between system-level and component-level opportunities, because by far the greatest ones are at the system level. True, a 25-cent transistor can ruin a billion dollar flight, but the use of that transistor came from a value judgment of the acceptable risk level for the system as a whole. The availability of most component-level opportunities, as it turns out, depends on prior system-level judgments. The possibilities list in the Aeronautics and Space Engineering Board challenge posed to the working group includes some of both. (This list is contained in the Statement of Task in Appendix A.) I will add three more: the definition of success, the use of software to reduce hardware and mission costs, and the use of ultraquality parts to reduce testing costs.

The second objective is to suggest a dozen or so guidelines—heuristics—for reducing or avoiding costs.

System-Level Possibilities

By far the most important decisions that affect cost—as well as performance and schedule—are made in the very beginning of a project. As a well-tested heuristic states:

In architecting a new aerospace system, by the time of the first design review, performance, cost and schedule will have been predetermined. One might not know what they are yet, but to first order, all the critical assumptions and choices will have been made that determine those parameters.

A number of studies of past projects have concluded that 75-90 percent of the end cost was determined up front. Thereafter, unless there was a major mistake, the most that was affected later was between 10-25 percent. This is not small, but is typically within the uncertainty of the initial cost estimates. So what are the system-level parameters? An amended list of possibilities follows. They are more or less in decreasing order of potential cost reductions.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×
Modified List I System-Level Opportunities For Cost Reduction
  • The definition of success.
  • The client' s acceptable risk level; for example, the utility of back-up hardware and prototypes.
  • The nature of the effort. Is it a single project or a product line (a continuing program); for example, is it a few large or many small spacecraft, an upgrading, or a planned product improvement?
  • Life-cycle costs and their annual cost profiles.
  • Improving schedule to reduce costs.
  • Upgrading or block changes?

Every one of these requires a value judgment by the client; that is, what is worth doing, what is acceptable, what is good, and what is not. But the client cannot make value judgments, even relative ones, a priori without some idea of what is feasible.

The Definition Of Success

For example, ask a typical client prior to conceptual design, ''What is most important: cost, performance, or schedule?'' And the answer is most likely to be either "Yes" or "It depends." The determination of what is feasible is largely up to the architect, who, of course, cannot make that technical determination without value judgments by the client as to what is wanted! A truly chicken and egg dilemma.

Therefore, the name of the game in the beginning, when cost is being determined to better than an order of magnitude, is a joint process between client and architect to create a conceptual design that is both desirable and feasible. A client who insists on defining the mission and its cost up front is likely to get neither in the end.

Therefore, to really reduce costs, the mission and its cost must be adjustable. There is a powerful heuristic that defines the initial ground rules:

Don't (either the client or the architect) assume that the original statement of the problem is necessarily the best, or even the right one.

So when is the right one stated? When has success been defined? In realistic terms, it is when there is mutual agreement that a complete, passable set of acceptance criteria have been developed for a plausible system. Only then is it even worth talking about costs.

It may surprise you, but clients do not really deal in costs, they deal in worth, which has psychological, political, social, and personal dimensions in addition to

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

the financial. If you do not believe it, talk to your real estate or automobile dealer! The only thing worse than the client starting with a fixed, immutable definition of success is having a fuzzy one, say a set of performance goals. Predictably, the clients will be disappointed, the builders frustrated if not bankrupt, costs will come in seriously out of line, and only lawyers will be happy. So decide on the set of acceptance tests early and as a guideline, "Keep It Simple Stupid!" For the scientists here, what you are willing to accept very strongly affects systems costs. That last 10 percent in capability or elaborate detail can be a back breaker.

An important thing to remember about cost reductions is that they come in different flavors. Some are true deletions of activity or equipment. Some are avoidances of overruns, cost uncertainties, and failures. Some are preplanned savings in foregoing options and eliminating contingencies based on better-than-expected progress to date.

But with all the best intentions, the estimated costs may still be too high. So downsize the mission. More exactly, Scope! Scope! and Re-scope! Make sure that the project is not so far-reaching that success is inherently costly. Carefully define what is necessary and no more. If in doubt, cut!

Once that is done, aggregate similar problems and partition the subsystems carefully. In partitioning, choose the elements so that they are as independent as possible, that is, elements with low external complexity and high internal complexity. For example, look for the reasons behind "contingency costs," determine the degree to which the system as a whole benefits from them, and then partition wherever possible to eliminate them. Many are due to suboptimizations that different structuring could eliminate.

Cost Risk

So far, so good. Then there is the question of cost risk.

What variation in cost is acceptable? What are the "tolerance limits" of the nominal cost? How much "insurance" is required to keep that risk in bounds? What are the sources of that risk (poorly characterized commercial off-the-shelf [COTS], immature technology, accident-prone launch vehicles, Congress . . . )? There are a number of ways to reduce cost risk without increasing cost. It is a profitable opportunity to exploit. One powerful heuristic is: Simplify!

If possible, have an alternate, simpler, competitive mission ready in the wings, preferably one with a similar cost-to-benefit ratio. That is, one of less cost and of acceptably less benefit. It is surprising what a bit of competition will do to keep costs within bounds. One common alternate to a new system is a somewhat less capable upgrade of the old one. Another is a completely different system that essentially accomplishes the same purpose. The longer a competitive alternative is available, the lesser is the cost risk for the mission as a whole.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×
The Nature Of The Effort

A critical value judgment is the level of commitment to the project that follows the current one. Is the current project a single, one-time project or part of a long-range program? Parenthetically, in the early 1960s Congress committed to a one-of-a-kind Apollo lunar mission, not to a continuing manned flight program, to the long-lasting frustration of NASA and considerable expense to the country. As an example, planetary flights in general tend to be one of a kind if for no other reason than that specific mission opportunities are so far apart in time (and often so different) that to do the next mission at a minimal cost requires major changes in system architecture and technology. On the other hand, Earth satellites, for both national security and scientific purposes, tend to be multidecade programs exploiting a common architecture.

Unfortunately, perhaps, but for understandable reasons, Congress very seldom commits to long-range programs, only to projects. An unstated assumption to the contrary can be very costly. There are a number of ways to "hedge" those costs: design in options such as the "scars" for airliner stretching, or partition the system into relatively autonomous components. Define success in reachable, intermediate steps.

Life-Cycle Costs

Life-cycle costs, while theoretically worthwhile, all too often run afoul of the governmental reality of annual appropriations. More than one project has had cost overrun badly because its year-to-year funding did not match efficient implementation. The government does not run on life-cycle costs. It runs on cash flow. No cash, no flow. Designing on the basis that minimal life-cycle costs will "automatically" generate annual appropriations almost never works. Annual appropriations come from continuing needs and go to "programs" that satisfy them—communications, weather, surveillance and, most recently, navigation.

The principal value of fife-cycle costs is that it enforces a consideration of operations costs, particularly the costs of testing and failure. It is unfortunate but true that most cost estimates in proposals are based on everything going according to a (life-cycle) plan. This is a near impossibility. It is not yet common practice to try to reduce cost by improving quality, though life-cycle cost strategies mandate it. In short, quality makes money.

Improving Schedules To Reduce Costs

From time to time assertions have been made that project costs can be saved by optimum scheduling. For example, NASA in its early years maintained that a specific Apollo schedule would result in the least cost, with greater costs on either side of it. In another case, an Air Force manager decided that the way to

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

reduce cost was to shorten the schedule and enforce it, regardless. Another insisted that tightening schedules always increased costs. Unfortunately, data from many projects do not support the one-to-one relationship assumed by any of these strategies. There are too many other factors involved, among them erratic cash flow, changes in procurement regulations, technological mismatches, unexpected events in lengthy projects, responsive management, and so on.

A more profitable area for cost reduction through scheduling is likely to be the timing of projects relative to each other. Permitting every project or program to have its own funding profile over time results in peaks and valleys in the sum of all of them. Timing them relative to each other, for steady cash flow for example, means that not every project can be scheduled for the same time, much less when it wishes. There have to be years of the planetaries, years of the orbiting telescope, years of Earth observation, years of manned flight. If all parties understand and agree, more or less, to such macro-scheduling, and can plan for it, the frustrations, tragedies, and costs of "no new starts" and the miseries of missed opportunities might be considerably reduced. Galileo is only one example of many in the terrible 1980s for planetaries. To work, of course, each project must stay within its cost boundaries and, if not, take the consequences.

And then there is cost allocation. For example, to achieve a reasonable balance between mission effectiveness and launch success rate, the ratio of spacecraft to launcher costs should be between 4 and 5 to 1. Higher than that risks the loss of a very high-value spacecraft due to a relatively cheap, relatively unreliable launcher. Lower than that invests too much in a support function (launching) that has little to do with the final mission of exploration, communication, intelligence, etc. One thing for sure, changing launch vehicles in midstream is very expensive. Some common causes are spacecraft weight growth or misestimation, launch vehicle fleet grounding, failure to meet a deadline, etc.

Upgrading Or Block Changing?

The effectiveness of upgrading as a way of cost reduction—as opposed to block changes—depends on where in the upgrading S curve the item is. Continually upgrading relatively mature hardware is likely to be less cost-effective than is continually upgrading rapidly evolving software. Note too that software upgrading can be, and has been, done remotely in flight—a major advantage for long-duration flights. On the other hand (all new) block changing of hardware is more straightforward than block changing software because the latter is more dependent on backward compatibility. The system-level value judgment here is the value to the client of being able to upgrade (or downsize) the mission, both before and after launch, and to exercise built-in options depending on the situation at the time.

It might seem that such flexibility would automatically be welcomed. But although the natural inclination of design engineers is for plenty of options, the

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

natural inclination of operators and clients is almost the opposite—no changes at all unless components have checked out ahead of time. What is it worth to the client? Better not prejudge.

Component-Level Possibilities
Modified List II Component-Level Opportunities For Cost Reduction
  • The use of software to reduce hardware and mission costs.
  • The use of ultraquality parts to reduce testing costs.
  • New technology versus space-qualified technology.
  • Military specification versus screened commercial parts (COTS, pro and con).
  • Piggyback payloads, etc.

I will address here only the first component.

Using Software To Reduce Hardware And Mission Costs

Where are the opportunities for using software to reduce costs? The most apparent opportunity is to use "smart" systems, both on the ground and in flight. For many missions, software can increase dramatically the mission's worth per dollar spent, even to the point where previously anticipated flights are not needed. And that, if planned in time, can be a real cost reduction.

Another possibility is to replace hardware with software in the interests of greater reliability and lower cost. Clearly the ratio of hardware to software, expressed as costs, has changed dramatically in the last decade from a cost ratio of 10:1 to 1:2. Part of this change is justified on mission effectiveness grounds; "smart" systems are not only more valuable, they cost less at the margin. Very soon software will be at the center of all real-time, software-intensive systems. Earth satellites and planetary spacecraft are certainly examples.

However, as software becomes a larger and larger part of mission costs, it becomes, and should become, a primary target for cost reduction. The question is how. It is a complex and controversial subject, perhaps better for a subsequent workshop. But from my point of view, the answer lies in new software architectures, reusable mission-certified modules, and progressive, integrated modeling.

For example, proponents of reusing software modules claim great savings. However, industry experience with COTS equipment and software has been mixed. On the one hand, the lack of knowledge of the details of a COTS component increases system risk, just as it did in the case of space lubricants whose composition was proprietary and unreleaseable. COTS "standards" can create otherwise unnecessary constraints on systems design. Supplier support for

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

specialized hardware and consumer software may evaporate with time or if the COTS is modified in any way. As the heuristic states, "COTS is COTS," period.

On the positive side, the use of COTS ought to reduce development time (and costs), and in a world of "time to market" economics, time is money. All things considered, it would seem the better part of wisdom to use only COTS coming from the same or similar programs and subject to the same acceptance tests.

Heuristic Guidelines For Cost Reduction1
  • Simplify! Keep it simple, stupid! (KISS).
  • Efficiency is inversely proportional to universality.
  • Scope! Scope! Scope!
  • Success and risk are defined by the beholder, not the architect.
  • In architecting a new program, all the serious mistakes are made in the first day.
  • In architecting a new system, by the time of the first design review, performance, cost, and schedule have been predetermined. One might not know what they are yet, but to first order, all the critical assumptions and choices have been made that will determine those key parameters.
  • Do not assume that the original statement of the problem is necessarily the best, or even the right one.
  • The most dangerous assumptions are the unstated ones.
  • Any extreme requirement must be intrinsic to the system's design philosophy and must validate its selection. Everything must pay its way onto the airplane.
  • In partitioning, choose the elements so that they are as independent as possible, that is, elements with low external complexity and high internal complexity. Choose a configuration with minimal communications between the subsystems.
  • "Proven" and "state of the art" are mutually exclusive qualities.
  • Complex systems will develop and evolve within an overall architecture much more rapidly if there are stable intermediate forms than if there are not.
  • In any resource-limited situation, the true value given a service or product is determined by what one is willing to give up to obtain it.
  • The bitterness of poor performance remains long after the sweetness of low prices and prompt delivery are forgotten.
  • Quality makes money.

1  

 Rechtin, E., and M. Maier. 1997. The Art of Systems Architecting. Boca Raton, Fla.: CRC Press.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Perspectives On Small Spacecraft: Results Of A Recent RAND Workshop1

Liam P. Sarsfield

RAND Critical Technologies Institute

Overview

Small spacecraft are becoming an increasingly important element of civil space policy. RAND is currently studying small spacecraft missions and their future in space science missions. This briefing provides a review of this on-going study and highlights from a recent RAND workshop covering trends in the development of small spacecraft. This material is presented as an in-process briefing. Results discussed here are preliminary and are provided in support of ongoing intellectual discourse on methods to reduce the cost of space science missions.

Background Of The Study

The purpose of RAND' s current work on small spacecraft is to review current and future programs to assess the efficacy of various development approaches and to gain insight into the performance of small spacecraft. In preparing the course of study, three key questions were established to guide the review of programs:

  • What role are small spacecraft playing in civil space programs?
  • What strategies have proven especially effective in reducing cost and increasing performance of small spacecraft?
  • What role does advanced technology play in the process of building small spacecraft?

At the conclusion of the study, policy options will be synthesized and recommendations prepared regarding future directions for small spacecraft programs.

The study focuses on NASA science spacecraft with a dry mass of under 500 kg. Some analysis of DOD unclassified programs is also included. Although the definition of what constitutes "small" is arbitrary, the 500 kg. limit captures the programs that are generally considered small within both NASA and DOD. Occasionally larger programs are referred to for comparative purposes.

The Role Of Small Spacecraft

Small spacecraft have become important policy tools. We already rely on small spacecraft to meet many of our national objectives in space and this trend is likely to continue. Small programs offer opportunities for international cooperation, in civil space most notably, but also possible future military cooperation in

1  

 From Cosmos on a Shoestring. Washington, D.C.: RAND Critical Technologies Institute. MR-864-OSTP (in press). Reprinted with permission.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

communications and remote sensing. As missions become smaller these programs will also carry an increasing burden of helping the U.S. maintain a skilled aerospace workforce.

On the economic side, small spacecraft currently represent a sizable national investment. Figure C-1 provides an estimate of NASA spending in FY96 for (1) all spacecraft research programs, and (2) for small spacecraft programs within the scope of this study.2 Cost breakdowns are provided in five areas; hardware (development of flight systems), launch systems, operations, research and analysis (R&A), and personnel. Approximately $4B is spent on spacecraft research programs within NASA, with $1B devoted to small spacecraft missions.

Small spacecraft are also of economic importance because they provide a means of conducting science at lower cost. They can be built faster requiring less engineering and testing; as a result they are cheaper. They also provide platforms for testing cost reduction strategies that have implications for programs of all sizes.

Competitiveness is another economic advantage inherent in small spacecraft. Built on faster timelines, small spacecraft are better able to approach the state-of-the-art. Since scientific objectives have remained ambitious spacecraft developers have been forced to aggressively pursue technology to increase performance.

One of the most important characteristics of small spacecraft, however, centers around a set of technical advantages. Firstly they are responsive to scientific needs. The ability to return results in 24 to 36 months is especially important in the realm of space science. Before budgets shrank spacecraft had already started to become leaner, a trend initiated by the demands of the science community:


"Rapid, elegant response is imperative . . . science is not best served by exclusive emphasis on major missions."

Crisis in Space and Earth Science

NASA Space and Earth Advisory Committee, 1986


"Efficient conduct of science and applications missions cannot be based solely upon intermittent, very large missions that require 10-20 years to complete. Mission time constants must be commensurate with the time constants of scientific understanding, competitive technological advances, and inherent changes in the systems under study. . .. NASA's new initiative for smaller, less expensive, and more frequent missions is not simply a response to budget pressures; it is a scientific and technical imperative."

Improving NASA's Technology for Space Science

NRC, 1993


2  

 This is a crosscut of the NASA budget prepared using RAND's RaDiUS (Research and Development in the United States) data base, which contains detailed budget information on the federal budget. Spacecraft costs are a summation of development costs for flight segments within the respective crosscuts. Launch costs include vehicle procurement and spacecraft-to-vehicle integration costs. Operational costs represent an aggregate of individual mission operations and data analysis (MO&DA) costs, construction of facilities (COF), and ground segment line items. Research and analysis (R&A) is a simple accumulation of these identified line items. Personnel costs are estimated as a fixed percentage of overall research and program management (R&PM) accounts.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Figure C-1

NASA spending on small spacecraft.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Figure C-2

Historical spacecraft mass trends.

Since the late 1980's there has been an evolutionary movement back to smaller missions. The Explorer program, NASA's oldest spacecraft series, evolved to Delta-Class missions, and then returned to smaller spacecraft with the formation of the Small Explorers (SMEX) Program. The shift to smaller missions is shown in Figure C-2. The mass of research spacecraft has dropped dramatically in recent years. The large missions remaining on the chart are, for the most part, legacy programs that were initiated prior to sharp budget reduction.

Risk is another technical factor that can weigh in favor of small spacecraft. There is certainly less financial exposure on a given mission and there is a proven track record of success for small spacecraft. With less at stake there is a tendency to believe that higher levels of risk-taking are acceptable on small missions. This is an area where additional analysis is needed. It is not clear whether future budgets can support a proliferation of small spacecraft. If additional initiatives are not forthcoming each small spacecraft will remain as important as their larger predecessors.

Analysis Of Small Spacecraft Programs

Smaller spacecraft are certainly faster and cheaper to build, but whether they are better is open to some debate. The content of NASA's science program has

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Figure C-3

The importance of technology in future small missions.

been reduced a good deal in recent years. Missions have been canceled (CRAF, OSL), deferred (Solar Probe), stretched (AXAF), downsized (SIRTF, FUSE), or turned off. It seems clear that the current generation of small spacecraft cannot maintain the pace of science without dramatic increases in system performance. Figure C-3 reflects NASA's reliance on new technology as the principal means of expanding the capability of small spacecraft, both to remain within anticipated budgets and to provide increasing scientific returns.3 There are indications that small spacecraft can deliver big science. An example is the Small Explorer Wide-Field Infrared Explorer (SMEX-WIRE) which, at 250 kg., will observe sources 500 to 2000 times fainter than the Infrared Astronomical Satellite (IRAS), which was launched in 1983 weighing 1100 kg.4

Although small spacecraft are indeed cheaper in an absolute sense, they can cost 2 to 3 times as much per kilogram when compared with larger spacecraft. Figure C-4 presents an assessment of spacecraft development cost relative to, and as a function of, dry mass. The figure includes the cost to manage, design, develop and test the spacecraft and instrument, and excludes any launch, ground support equipment, and operational costs. The chart shows that many small spacecraft, in a relative sense, are more expensive than larger ones. The chart also

3  

 Space Science for the 21st Century, NASA Office of Space Science, August, 1995, p. 25.

4  

 Minutes of the NASA Astrophysics Subcommittee, September 1994.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Figure C-4

Spacecraft cost per kilogram comparison.

shows that some small spacecraft programs demonstrate a linear relationship between mass and relative cost. The principal reason for the higher relative cost of many small spacecraft is the complexity inherent in trying to integrate compact systems, advanced technology, and redesigned instruments into a smaller package. Future analysis will seek to normalize the cost of complexity in these missions and perform a more revealing comparison.

As part of the study, detailed cost estimates were prepared for twelve NASA small spacecraft.5 Based on current mission data, Figure C-5 depicts a breakdown of costs for an average NASA small spacecraft mission. It is not remarkable that small spacecraft should cost less to develop that larger ones. The question remains: how much have ''faster, better, cheaper'' initiatives impacted mission cost? The SMEX program provides an excellent data point. The Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) mission was the first in the Small Explorer (SMEX) series and an early demonstration of the movement to smaller spacecraft. It was, however, a spacecraft that was built according to more or less traditional practices, before designing to lowest cost became a mission priority.6 In FY96 dollars the total mission cost for SAMPEX, including estimates of civil servant labor costs, was approximately $81M. The follow-on

5  

 Detailed cost data was provided by the respective NASA program offices: Discovery, NMP, Explorer, and Surveyor, for missions in the 500kg category. Each program provided information against a standard cost template which included estimates of civil servant resources and government furnished equipment.

6  

 O. Figueroa, SAMPEX, in Wertz and Larson, Reducing Space Mission Cost, 1996.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Figure C-5

Distribution of TMC cost elements for current small spacecraft.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

SMEX spacecraft, the SMEX-Lite missions, will take advantage of all that has been learned at NASA GSFC. They are projected to have a TMC of $65M, including launch and civil servant costs, more than a 20 percent reduction.

Although real savings have been realized from the advanced practices being used to build the current generation of spacecraft, there are some reasons for concern. In the drive to reduce mission cost it is essential not to overlook hidden costs which can cause:

Lessons not to be learnedin small spacecraft programs there is usually little time or money to document team experiences. Travel funds are in short supply, discouraging the communication and cooperation required to vitalize new programs and train new people.

Poor working environmentsthere is danger of creating "spacecraft sweatshops" with working conditions that exhaust and demoralize project personnel. Many of the projects examined in the study reported problems with employee fatigue, stress-related ailments, and retaining key staff. On flight projects it is not uncommon to see employee timesheets in excess of 70 to 80 hours per week, much of it representing uncompensated time. To some degree this is a fact of life in space development programs, but in past programs such extremes were usual only in the integration, test, and launch phases. The concern now is that excessive workload is now appearing throughout the development cycle. Compounding this problems is the pressure to further reduce schedule.

Loss of marginmost small spacecraft are being built with very small design and operation margins in an effort to save cost. Small margins lead to elimination of redundant strings, with a subsequent loss of opportunity to fly advanced designs. Lean margins can also drive up non-recurring engineering costs, since it can be difficult to design systems with little margin. Mission designers must also prepare and verify spacecraft operational sequences that exhibit very little room for error. Another downside is that opportunities for commonality/standardization are frequently foregone because there is not enough money or technical performance left to develop them.

Limited profitabilitymany commercial developers complain that small spacecraft are not profitable undertakings. Small spacecraft builders often operate as 'skunk works' within a larger corporation. Their viability is increasingly tenuous in a low-profit environment. Capital equipment funds for tooling, new facilities, training and certification, are also hard to come by.

These costs, though difficult to quantify, are, nonetheless, real. Failure to account for them will inevitably affect long-term quality and performance.

RAND Workshop Results

A workshop to examine trends in the development of small spacecraft was sponsored by RAND in mid-August of 1996 in Washington, D.C. The purpose of

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

the workshop was to bring together engineers, managers, and policy-makers to discuss progress in a forum held without attribution. The results of the workshop are summarized into five areas; cost trends, reducing TMC, commonality, technology, and policy.

Cost Trends
  • Emergence of small spacecraft:
    • Driven not just by budget.
    • Small missions are responsive to change (political, economic, and scientific).
    • Small spacecraft philosophy impacts all aspects of management and engineering—a new paradigm.
  • Measurement of costs:
    • Should be public to inspire competition.
    • Should be inclusive of all costs (including overruns).
  • Overall trends:
    • Subsystems and, in some cases, the whole spacecraft are now commodities.
    • Cultural change to a new, smallsat paradigm has not yet occurred within NASA.
Reducing Tmc
  • Impact of commercial systems:
    • Direct purchase of COTS buses will allow some missions to substantially cut TMC.
    • Commercial suppliers are betting on demand pull to increase sales.
  • Technical approaches:
    • Replace traditional Phase A-E with in-process, as-needed reviews.
    • Maintain a level of documentation rigor appropriate for small spacecraft. Avoid "we'll fix it in I&T", focus on firm requirements and upfront engineering.
  • Management approaches:
    • Team size and schedule are the principal determinants of cost.
    • Trust "contractor best methods" (for established entities)—corporate reputation is at risk and infrastructure is in place.
    • Process improvement is at least as important as new technology in bringing down TMC.
    • Hidden costs often lie within programs (poor profits, employee overload, creative bookkeeping...).
Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Spacecraft Commonality
  • Future planetary and space physics missions are moving to higher levels of instrument/bus integration—a move away from purchase of commercial buses.
    • However, future constellation missions seem ideally suited to bus purchases.
    • Scale ability of future spacecraft will allow downward and upward propagation of new designs.
  • Communications and operations:
    • Internet-based team integration and operations is an emerging reality.
    • Efforts to encourage working-level communication and cooperation (colloquia, personnel exchange . . .) are a wise investment.
  • Articulating requirements:
    • Matching technology solutions to spacecraft requirements requires continuing conversation—roadmaps often prevent this.
Technology Trends
  • Retiring risk of new technology:
    • Demonstrator missions don't fly the high risk technologies.
    • Risk should be tied to the requirements of the spacecraft designer, realistic budget/program portfolio, and government performance-based planning (GPRA).
  • Planning technology programs:
    • NASA technology programs should follow the USAF "mission-pull" model.
    • Save a portion of the technology budget for projects unrelated to future missions—strong R&D base.
    • Technology roadmaps bear no relation to budgets.
    • NASA should understand commercial investment in space technology and not compete—identify unique requirements.
  • Future technology programs:
    • The loss of SDIO/BMDO technology funding will constrain the performance of future small spacecraft.
    • Commercial IR&D programs are the big spenders.
Space Policy
  • Future budgets:
    • Budget constraint will be a long-term phenomenon.
    • No more "bet it all, lose it all."
  • Political support:
    • Effort needed to educate Congress on the need for occasional high-risk technology missions.
Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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    • High risk in selling promise ("order of magnitude reduction in . . .") in this environment.
  • Metrics:
    • Stop counting "what we spent," measure "what we did."—Technology programs should be peer reviewed by the people that use the technology.
    • Ask NASA's customers to evaluate performance, not NASA.
Conclusion

The purpose of this NRC workshop is to explore new ways to reduce mission cost. Significant effort has already been directed at the challenge of simultaneously reducing cost and increasing performance. As a result both government and industry have discovered ways to accomplish significant results.

It is likely that additional cost savings will be more difficult to extract. Fundamental changes are required in our approach to conceptualizing spacecraft, and new techniques and processes must be defined to manufacture and operate them. Fortunately, technology advances at a steady enough pace to ensure that new solutions lie around every comer.

In embracing new approaches it is essential to integrate risk management more thoroughly into mission planning and implementation. Greater reliability should be synonymous with increased performance. Spacecraft of the next millennium should not only be less expensive, but also longer-lived and ever more reliable.

Achieving these objectives will require careful planning and wise investment of limited resources. The results of this workshop will no doubt help outline the next steps.

List Of Acronyms

ACE

Advanced Composition Explorer

AM

ante meridiem (the AM-1 is NASA's Earth Observing System Satellite with a 10:30 a.m. descending node)

AXAF

Advanced X-Ray Astrophysics Facility


BMDO

Ballistic Missile Defense Organization


Chem

Earth Observing System Chemistry Satellite

COBE

Cosmic Background Explorer

COTS

commercial-off-the-shelf


EUVE

Extreme Ultraviolet Explorer


FAST

Fast Auroral Snapshot Explorer

FUSE

Far Ultraviolet Spectroscopic Explorer

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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GSFC

NASA Goddard Space Flight Center


HETE

high energy transient experiment


I&T

integration and test

IMAGE

imager for magnetopause-to-aurora global exploration

IR&D

in-house research and development

IUE

International Ultraviolet Explorer


MAP

Microwave Anisotropy Probe


NEAR

Near Earth Asteroid Rendezvous


PM

post meridiem


REX

radiation experiment


SAMPEX

Solar, Anomalous, and Magnetospheric Particle Explorer

SDIO

Strategic Defense Initiative Office

SIRTF

Space Infrared Telescope Facility

SNOE

student nitric oxide experiment

STEP

Space Test Experiment Program

SWAS

Submillimeter Wave Astronomy Satellite


TDRS

Tracking and Data Relay Satellite

TERRIERS

tomographic experiment using radiative recombinative ionospheric EUV (extreme ultraviolet) and radio source

TRACE

Transition Region and Coronal Explorer

TRMM

Tropical Rainfall Mapping Mission


WIRE

Wide-Field Infrared Explorer


XTE

X-Ray Timing Explorer

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Influence Of Technology On Space Mission Costs

Frank J. Redd

Utah State University

Introduction

The consideration of new technology for introduction into space mission planning can influence cost, risk, and performance in many significant ways. The evaluation of this influence requires a system-level assessment of these factors as technology trade-off investigations are conducted to compare off-the-shelf and new technology solutions. Planners must beware of temptations to reach for new technology to solve excess cost problems. The space design graveyard is littered with the remains of those who have tried.

New technology can present possibilities for space mission cost reduction by:

  • introducing cheaper components (e.g., advanced electronics)
  • introducing less complex components (e.g., self-contained thrusters)
  • achieving higher performance
  • reducing volume, mass, and power requirements
  • enabling cost and performance trade-offs

These factors may allow additional cost reductions that may be realized from reduced ground test requirements, lower-cost launch options, shifting requirements from one subsystem to another, and from reduced system complexity. In estimating potential reductions, however, it is crucial that cost projections include accurate assessments of the nonrecurring costs associated with technology development, validation, and qualification. The ability to estimate these costs accurately is a strong function of the maturity of the technology.

The necessity for space qualification introduces added complexity into assessing costs associated with introducing new technology into a space mission. Can a new technology be qualified on the ground using simulations of the space environment or must it actually be flown in space? The answer to that question may depend on who is answering it. Finding an agreement between the technology developer and the space mission director is often very difficult. Typically the developer considers the technology ready for flight before the mission director does. If there is a disagreement, funding must be provided to conduct the necessary testing to enable the technology transition.

There is a useful discussion of the influence of technology on space mission costs in Reducing Space Mission Cost (see Ch. 3 in Wertz and Larson, 1996).

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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This book also contains some excellent case studies that include the effects of the use of new technology. The decision to consider the use of new technology is a critical one that is wrapped up in the original mission design philosophy. The Near Earth Asteroid Rendezvous (NEAR) design philosophy allowed the use of new technology only when it could be shown to directly reduce mission cost. "New technology was used when it was necessary for the execution of the mission and not because it was neat to do so" (Maurer and Santo, 1996). The first of NASA's Discovery missions, the NEAR spacecraft was launched on February 17, 1996. It was completed under cost ($108 million versus a ceiling of $150 million) and ahead of schedule (27 months versus the goal of 36 months). New technologies employed under the guiding philosophy included (1) the use of gallium arsenide solar arrays, (2) the use of a solid-state recorder, (3) the use of a sodium iodide crystal inside a bismuth germinate crystalline shield for rejection of the interplanetary background in the gamma ray spectrometer, (4) the use of a scaled down but more reliable version of the Clementine laser range finder, and (5) the use of software autonomy rules for use during long cruise portions of the mission (Maurer and Santo, 1996).

In summary, the decision to introduce new technology into a space mission involves intelligent, thorough cost/risk trade-off assessments that must be conducted at the system level. These assessments must include accurate estimates of the nonrecurring costs associated with development and space qualification. An up-front mission philosophy that governs trade-off decisions (e.g., the NEAR philosophy) should be articulated. In all cases, available off-the-shelf technologies must be included in the trade-off considerations.

Space Qualification

Consideration of the use of new technology in a space mission must address the level of space qualification necessary to reduce the risk to an acceptable level. "Unfortunately, there is no universally accepted definition of what makes a particular component 'space qualified'" (Wertz and Larson, 1996:66).

At best one would hope that the component had actually operated to required performance levels in the space environment. To achieve this the components must either have been flown as an operational component or have been operated as part of a space technology demonstration experiment. Even then one has to be concerned with the number and breadth of the testing. Ground testing in simulated space environments can reduce space qualification costs if the simulated environments are sufficient to qualify the component. The cost/risk trade-offs in seeking an acceptable level of space qualification are part of the reason it takes so long to get some of the promising new technologies into space.

In some instances formal technology transfer programs have been devised to develop a planned movement of technology from the laboratory into space. NASA's New Millennium Program (NMP) is one of these. Implementation of

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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this program has led to the establishment of a group of Integrated Product Development Teams that are examining technology needs for future space missions. One of the products of these teams is a collection of technology roadmaps that chart planned technology development versus identified technology need dates. A series of planned technology demonstration flights are integrated into the NMP to provide flight opportunities in the space environment. Much of the information in the following sections is taken from the 1995 New Millennium Program Technology Roadmaps (NASA, 1995). Other sources are the Tenth Annual American Institute of Aeronautics and Astronautics/Utah State University (AIAA/USU) Conference on Small Satellites (1996) and other media sources. The presented information is by no means exhaustive. More detailed information can be found in the original sources. The technology information is keyed to availability dates of 2001, to support the Mars 2001 mission, and 2004 to support Earth observation missions.

Space Electronic Systems

The general goals for space electronics systems are (1) reduction of electronics subsystems mass, volume, and power requirements; (2) increased use of commercial components; and (3) fault-tolerant on-board computing to enable onboard data processing and autonomous spacecraft control and operation. The latter goal is intended to introduce large cost savings by a reduction of ground operations personnel requirements. Specific goals versus current state of the art for 1999 are (1) a reduction in semiconductor feature size from 0.7 to 0.4 microns, (2) an increase in processor million instructions per second (MIPS)/W from 1.8 to 14, (3) a decrease in processor mass from 1000 to 100 grams, (3) an increase in memory storage from 0.1 to 500 Mbits/gram, and (4) an increase in power electronics output from 16 to 250 W/cm3 and 0.01 to 6 W/kg. Again, details are provided in the New Millennium Program Technology Roadmaps. Some flight validation will take place on the first technology demonstration flight, Deep Space 1, in late 1997 (NASA, 1995).

Additional technology considerations in designing space electronics systems include decisions on the use of space-qualified parts and the required levels of radiation hardening. During 1965-1980, special process, testing, and documentation requirements were introduced to provide electronics parts that were "space qualified." These parts are usually much more costly than their commercial counterparts. Specification of space-qualified parts reduces the risk of failure at the expense of significantly increased costs. These costs can sometimes be avoided by combining the use of commercial, high-reliability parts with fault-avoidance design. Wertz and Larson (1996:295-300) present a good discussion of the use of derating, environment protection, screening, and fault-tolerant design.

Required levels of radiation hardening are mission dependent and must be considered in the design. Choices of electronic systems, components, and parts

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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must conform to radiation-hardening requirements. Modem electronics parts with high-density integration tend to be less tolerant to radiation effects than older ones. The sensitivity to radiation drives trade-off decisions among parts and component selections and shielding designs.

An example of space computer development trends was described by Gaona (1996) in the recent Tenth Annual AIAA/USU Conference on Small Satellites. Gaona described a Sandia-developed, radiation-hardened computer that uses the NASA Goddard R3000 ''Mongoose'' for its central processing unit. The computer uses a high-reliability 32-bit processor and is capable of 10 MIPS at 480 Mbits/s while consuming only 1.2 W.

Electrical Power

The NMP emphasis in power technology improvements focuses on silicon versus gallium arsenide solar cell cost versus performance trade-offs. Included in the technology roadmaps are multiband gap planar photovoltaics that project 26 percent efficiency, flight tested and qualified by 1999, and a SCARLET concentrator array that will achieve 1.5 times the present state-of-the-art efficiency at one-half the cost. The SCARLET Concentrator will fly on the NMP Deep Space 1 mission (NASA, 1995).

For power storage the NMP emphasis is on lithium-solid polymer battery technology. A space prototype providing 150 Whr/kg at "low" cost is planned for availability by 1998 (NASA, 1995). Nearer-term options include nickel metal hydride and lithium ion technologies. Emphasis in the AIAA/USU Conference on Small Satellites was on nickel hydrogen performance improvements (approximately 55 Whr/kg) (Machlis, 1996; Caldwell et al., 1996).

Structures And Mechanisms

The primary effort in improving structures and mechanisms has been on reducing mass and increasing stiffness through the use of new materials. The introduction of graphite/epoxy into spacecraft structures has already happened (e.g., the use of graphite/epoxy in the recently launched Mars Global Surveyor reduced the mass to one half that of the Mars Observer). Outyear technology possibilities include the use of inflatable structures that could be 2-10 times lighter, 10 times smaller in stowable volume, and 20 times less expensive than current approaches. Space-qualified inflatable structures will not be available until after 2000 (NASA, 1995).

Exciting developments in multifunctional structures (MFSs) are just now emerging. MFS concepts envision the integration of electronics and thermal functions onto lightweight structural components. Successful integration will eliminate cables, electronic boxes, and connectors from the spacecraft. Electronics will be bonded directly to the load-carrying thermal structural panel. MFS concepts promise a doubling of current payload mass fractions.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Communications

The combination of smaller, low-power spacecraft with sophisticated, high data-rate sensors is aggressively driving the need for higher performance communications systems. The NMP communications roadmap identifies key capability needs such as (1) miniature deep-space communications systems, (2) extremely large bandwidth systems for near-Earth missions, and (3) capabilities for in-space interconstellation communications. Needed technology developments include:

  • extremely high bit-rate transponders
  • high throughput on-board transponders
  • phased array antennas
  • high data-rate radio frequency transmitters
  • low-mass, low-power integrated circuits

Schedule details are found in the NMP Roadmaps (NASA, 1995). The major thrusts are in deep space systems are Ka Band (32-GHz) systems, highly miniaturized transponder/transmitters, highly efficient power amplifiers, and lightweight, deployable antennas. Near-Earth thrusts include high data-rate transmitters incorporating data compression techniques and phased array antennas (NASA, 1995).

Optical communications systems offer some significant advantages over radio frequency. These include reduced size, aperture gain, and unlimited bandwidth. The NMP roadmaps indicate initial availability in 1997-1998 (NASA, 1995).

Attitude Determination And Control

The penetration of nearly all space missions by small spacecraft has driven attitude determination and control (AD&C) technology very hard. The primary drivers are the need for low-mass, low-volume components. Fortunately, the reduced mass and inertia of small satellites allows the use of very low torquing systems.

In the area of attitude determination, significant progress has been made in attitude sensing technology. Some new sensing devices are already in use; some are very near. Examples of these are small, lightweight star sensors enabled by charge-coupled device arrays and increased on-board computing capability; low-cost, turned-rotor gyros; high-precision magnetometers; and differential Global Positioning System attitude sensing. Miniature electromechanical systems technology envisions accelerometers and gyros on-a-chip that will revolutionize attitude sensing and control. New low-force torquing devices are being introduced into spacecraft attitude control system design very quickly. Such devices include magnetic torquers, arc jet electric propulsion (on the shelf), ion thrusters

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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(baselined for flight on Hughes communications spacecraft and the NMP Deep Space 1 mission), pulsed plasma thrusters, and self-contained thrusters using evaporation and sublimation techniques.

The development of AD&C hardware is on a very steep slope with new devices appearing every day. Software developments enabled by increased onboard computing capacity are also significant factors in increasing AD&C capabilities. The combination of increased on-board computing capacity, reliable small sensors, and robust control software is a major factor in enabling future spacecraft autonomy. Autonomy, in turn, will generate large decreases in operations costs by reducing manpower requirements.

Conclusion

The potential introduction of new technology into spacecraft programs includes strong interactions among cost, performance, and risk factors that require intelligent trade-off analyses before commitment to a decision. Significant spacecraft technology developments are on the horizon that will allow incorporation of new capabilities into space mission design at potentially lower cost. The readiness of these developments depends on the required levels of space qualification and the costs associated with achieving these levels. Programs such as the NASA New Millennium program are designed to provide the planning and resources to enable the technology transition activities required to provide space-qualified hardware and software for future space missions. The impact of future technology development on future space mission costs and performance will be significant.

References

Caldwell, D.B., C.L. Fox, and L.E. Miller. 1996. Powering small satellites with advanced NiH2 dependent pressure vessel (DPV) batteries. In Proceedings of the Tenth Annual American Institute of Aeronautics and Astronautics/Utah State University (AIAA/USU) Conference on Small Satellites. Logan, Utah: Utah State University, Center for Space Engineering.


Gaona, J.I., Jr. 1996. A radiation-hardened computer for satellite applications. In Proceedings of the Tenth Annual AIAA/USU Conference on Small Satellites. Logan, Utah: Utah State University, Center for Space Engineering.


Machlis, M.A. 1996. On orbit NiH2 battery performance and problem solving on the Apex spacecraft. In Proceedings of the Tenth Annual AIAA/USU Conference on Small Satellites. Logan, Utah: Utah State University, Center for Space Engineering.

Maurer, R.H., and A.G. Santo. 1996. The NEAR Discovery mission: lessons learned. In Proceedings of the Tenth Annual AIAA/USU Conference on Small Satellites. Logan, Utah: Utah State University, Center for Space Engineering.


NASA (National Aeronautics and Space Administration). 1995. New Millennium Program Technology Roadmaps. Washington, D.C.: NASA.


Wertz, J.R., and W.J. Larson, eds. 1996. Reducing Space Mission Cost. Dordrecht, The Netherlands: Kluwer Academic Publishers.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Summary Of Techniques For Reducing Space Mission Costs

Wiley J. Larson

International Space University and United States Air Force Academy

The objective here is to capture useful strategies for reducing the cost of space missions and to provide the information to industry and government program managers to implement. There are several approaches to reducing space mission costs, and the key is to carefully select and implement an integrated combination of the approaches for a program. Potential cost reduction approaches include the following:

  • use policy issues that affect cost to reduce cost
  • limit the acquisition process to a shorter time
  • manage the requirements process
  • develop and employ cost-effective mission concepts
  • emphasize reducing costs while managing the program
  • incorporate the design, development, and test of spacecraft to reduce cost
  • emphasize mission operations and ground infrastructure concepts
  • consider technology to reduce cost
Summary Of Policy Issues That Can Affect Cost

Develop and implement Department of Defense (DOD) and NASA integrated plans and architectures. Build credibility for your program in the executive and legislative branches of government. Build a strategic road map that provides a common frame of reference. Make dual use of information, hardware, software, and programs among DOD, NASA, and industry. By merging selected NASA and DOD capabilities (for example, weather), cost can be reduced.

Implement an accounting system for mission operations by making the developer and operator responsible for cost of operations and by making as much of operations as possible direct costs. Continue by making users and operators accountable for funding and system cost.

Improve the acquisition process to facilitate cost reduction by increasing procurement stability to reduce wasted effort and by increasing funding stability to reduce the cost of developing systems by a significant percentage. Use incremental funding where appropriate. Set up an organizational structure and acquisition process to facilitate trading on requirements and eliminate all noncritical requirements. Consider implementing stringent cost control methods such as canceling programs for 15-30 percent cost overruns or six-month schedule overruns.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Eliminate any unnecessary military standards and specifications, and facilitate the use of commercial best practices. Increase the dollar limit for noncompetitive contracts, and make users and operators accountable for funding and system cost. Then provide incentives for government and contractors to reduce cost—don't penalize your program team for taking calculated risks.

Manage The Requirements Process To Facilitate Reducing Cost

Identify and implement a process for managing requirements that provides the user or customer what they need; however, generate fiscally responsible requirements, and make a concerted effort to identify the truly difficult and costly requirements. Bundle program requirements to facilitate affordable systems. Establish a timely process to trade on the requirements and negotiate acceptable compromises by motivating key players in government and industry to identify tough requirements and provide options to change or meet them.

Develop better integrated mission concepts, document them, and be willing and able to negotiate by integrating space into the everyday lives of users and operators. State your program requirements in a more constructive fashion by describing what is needed, not how to provide it, by including ranges of performance and by stating the rationale or reason for requirements—the goal is to communicate.

Develop Cost-Effective Mission Concepts

Recognize and facilitate different classes of missions and payloads, select the proper class of mission and payload, then implement accordingly. Perform up-front space mission engineering to develop innovative mission concepts using air, space, land, and sea resources, but implement them conservatively. The most important cost savings occur while deciding how to meet operational requirements, not how to implement a set of technical specifications. Do trades among mission elements early, as they provide the best opportunity for reducing cost. Examples include data processing, orbit insertion, propulsion, and autonomy.

Make maximum use of cost-effective commercial products—look for commercial capabilities first, then remember that large missions can be done by using several large or many small spacecraft—many trade-offs exist. Technical risk and cost may increase when you put all of your eggs in one basket, for example, dollar per bit may be lower for one large integrated spacecraft, and the consequence of failure is also larger. Use a "design-to-cost" approach and adjust the mission concept, requirements, and design to meet a life-cycle cost goal.

Emphasize Managing Programs

Carefully select an experienced program leader and give him sole responsibility and accountability for development, test, and operations; then support him or her. Use committees to gather sage advice, wisdom, and good ideas but don't

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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make decisions by committee—when things go wrong, it turns out no one can remember being at the meeting!

Select your program leadership based on the type of program and desired attributes for a specific program (large or small, technical or not, hands on, motivation, and skill mix). Build competitive hardware; do not focus on paper studies. Actively use prototyping and simulation where appropriate. Minimize documentation and reviews. Only develop and maintain necessary documentation. Zero-base documentation works, but it is painful. Explore using existing contractor documentation and augment, if necessary, and reuse generic documentation.

Track cost and schedule in near real time—work the problems in real time and don't accept schedule slips. Encourage mutual trust between the government and contractor team—integrated product teams can work well. Facilitate easy communication among all players. Determine the appropriate approach for government interaction with contractors (small government and contractor program office—separate or joint). Use concurrent design and fabrication judiciously and avoid jointly funded programs.

Manage the requirements and design change process with an iron fist once you have selected the proper philosophy (in any event do not allow changes on changes to go unchallenged). Government program managers can save time and money by using contractor/contracting officers to procure hardware, software, and services as well as some facilities. Be wary of reducing contract funding by 10 percent each year because it causes a very destructive phenomenon. Consider canceling lower-priority activities and leave others unchanged.

A compressed schedule can reduce overhead of a "standing army." It forces your program to move rapidly and can reduce cost. A tight schedule can be a wonderful excuse to expedite procurement.

Reducing the budget should result in reduced capability. If not, you are reducing program margin and increasing risk. Use increased spacecraft margins to reduce cost because it provides more flexibility and makes the system more robust during the development and operations phases. It can also reduce operations, engineering, and manufacturing costs. Make maximum use of cost-effective commercial products by looking for commercial capabilities first. Use of commercial off-the-shelf items should be strongly encouraged. Share cost among nations, organizations, and companies. This may reduce the cost of one piece, but be sure that the overall cost will be higher. More interfaces usually imply more complexity and higher cost.

Incorporate Spacecraft Design, Development, And Test Strategies

Develop and use standard interfaces where possible. Automate appropriate spacecraft functions to reduce life-cycle cost. Automating the wrong ones will drive costs up. We know that automating things such as anomaly detection can

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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work, but anomaly resolution has been less successful. Automating some functions on the spacecraft to ease operations cost has, in some cases, had the opposite effect.

Consider weight-optimized, smaller spacecraft versus fewer larger spacecraft to reduce launch cost. This may drive spacecraft cost up. Develop designs that are robust to known or anticipated changes (historically based). Shoehorning software into a computer and increasing the speed at which a code operates is one of the most expensive things we can do. Mass, power, and throughput must be robust. Make considered, maximum use of existing capabilities and infrastructures if they are cost effective.

Use the 80 percent rule in developing multiuser systems; but trying to be all things to all users drives the cost through the roof. Don't sacrifice on integration and test; however, it is possible to eliminate some development and performance tests if qualification tests are used. Emphasize validation and testing from day one.

Include Mission Operations And Ground Infrastructure Concepts

Develop and use standard interfaces, protocols, and procedures. Software and procedure reuse coupled with up-front participation can reduce cost significantly. Automate appropriate functions to reduce cost and enhance reliability. Eliminating one low-cost operator and replacing him, or her, with a high-cost software maintainer is not cost effective in many cases. Use automation to enhance reliability and reduce life-cycle cost. Carefully consider data flow to minimize organizations and steps. Review data push and data pull approaches. The data pull approach has the potential to reduce the cost of data. Implement an accounting system for mission operations and make the developer and operator responsible for the cost of operations. Make as much of operations as possible direct costs. Allow adequate spacecraft margin needed for expensive analysis during development and operations. This makes the spacecraft more operable and less expensive to operate. Check mission and spacecraft operability prior to committing to mission and spacecraft design. Periodically revisit the design throughout development.

Identify Technology

Focus on technologies that provide savings in the "-ilities"—producibility, testability, reliability, and operability—are prime. Fly operational demos in addition to tech demos—the philosophy and approach may be different. Technologies to reduce mission operations cost include autonomous orbit determination and maintenance, on-board data processing and health monitoring, standardized communication interfaces, use of spacecraft command language, and on-board

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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solid-state memory. Technologies to reduce the cost of space missions include those that improve up-front development of mission concepts, operations planning, and systems engineering. For example, miniaturization of electronics, solar electric power generation, and electric propulsion, autonomous navigation of spacecraft, the Global Positioning System, or other technologies.

Summary

We share many of the same problems; however, we can work together to solve many of them. We've seen many useful approaches and many examples of how to reduce cost, but the strongest approach is to select a combination of approaches that suit a program's particular needs.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Mars Exploration Program Strategy: 1995-20201

Donna L. Shirley and Daniel J. McCleese

NASA Jet Propulsion Laboratory

Abstract

In the wake of the failure of the Mars Observer mission in 1993 a long-term program of robotic exploration of Mars was established. The themes of the Mars Exploration Program are to understand Life, Climate and Resources on Mars, with these themes tied together by the common thread of Water. The Mars Exploration Program comprises at least one Discovery mission (Mars Pathfinder), the Mars Surveyor Program, plus sample return missions and other missions to prepare for possible human expeditions to Mars. The program will launch (on average) two missions every 26 months. The missions launched between 1996 and 2001 will include a lander and an orbiter at each opportunity, launched on the Delta family of launch vehicles. International participation is an important factor in the program, and relationships are being established with Russia, Europe and Japan. The program is severely cost constrained, with missions costing about $150M apiece or less, including launch and operations.

The "Water Strategy"

The Mars Exploration Program will continue the exploration of the red planet which has fascinated humankind for thousands of years. Robotic spacecraft began visiting Mars in 1965, and landed on the surface in 1976. Mars was found to be a planet of stark contrasts. The surface features range from ancient, cratered terrain like Earth's moon, to giant volcanoes and a canyon as long as the United States is wide. The atmosphere is less than 1 percent as dense as Earth's, but there are constant polar caps with reservoirs of water ice. Close-up, Mars resembles an earthly desert like California's Mojave, but there is evidence that water once flowed and cut channels on the surface.

1  

 Copyright © 1997 by the American Institute of Aeronautics and Astronautics. Reprinted with permission.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

NASA Administrator Dan Goldin and NASA Associate Administrator for Space Science Wes Huntress have agreed on a strategy for the exploration of Mars for the next 10 years. The strategy is to explore and study Mars in three areas:

  • evidence of past or present life
  • climate (weather, processes and history)
  • resources (environment and utilization)

Mars will be our first footfall in the search for life beyond Earth. We began our search for life on Mars using the tools of astronomy. As we extend our reach with new astronomical tools in search of planets and life in other solar systems, Mars remains our touchstone for understanding planetary evolution different from Earth's. Robots and humans will go to Mars to explore intensively. We seek the markers of life from which we will learn how to find and study hospitable worlds. Using both remote presence and physical contact, our skills will be honed and our reach lengthened sufficiently to understand whether we occupy a unique place in the universe or one of many such places scattered throughout it.

If life ever arose on Mars it would almost surely have been connected with water. And understanding the water-connected processes which led (or didn't lead!) to life on Mars will help us understand the potential for life elsewhere in the Universe. The climate and resources themes are also connected with the search for water on Mars. When and where was water present in the past, and what is its current form and amount? We know from previous missions that the Martian polar caps include water ice as well as frozen carbon dioxide. The Viking and Mariner 9 orbiter images show evidence of past great floods (the Pathfinder lander is planning to land in such an area) and of dry rivers and lake beds. Where did the all the water go?

Water is key to climate both on Earth and Mars, and understanding the history of the Martian climate will help us understand better the Earth's climate change processes.

Water will also be a major resource for future human exploration of Mars, and if we understand how Mars evolved (including discovering the sources and sinks of water, past and present) we may be able to locate reservoirs of water for human use.

A Series Of Missions To Build Up "Water" Knowledge

Our exploration of Mars for greater understanding of life, climate and resources will focus, in large part, on the study of water and its role in the history of the planet. How do we go about finding out about water on Mars? Dr. Daniel McCleese of JPL, the Mars Exploration Program Scientist, and Dr. Steven Squyres of Cornell, the head of the Mars Science Working Group, led that group to define a strategy for the "water search." They looked at how small Mars

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

orbiters, landers, ''networks'' of landers, and sample returns could be combined in a logical progression of missions that will build up an understanding of how water has existed and is existing on Mars today.

Small orbiter missions will search for accessible water (we know that ice is accessible at the poles, but are there reservoirs underground or in the soil?). They'll search for ancient sediments and hydrothermal deposits (dry lake beds and hydrothermal vents). They'll provide data needed to understand the present Mars climate and study how water escapes from the atmosphere into space. The orbiters will also study the surface of Mars and identify good landing sites for the landers, and provide radio links between the landers and the Earth.

Small lander missions will search for carbonates and evaporites that could only have formed in the presence of water. Landers can investigate water reservoirs in detail: for example, they can measure the amount of water which is in the soil, or examine the polar ice caps (using drilled core samples and electro-magnetic sounding) to see how, when, and how much ice was laid down. Investigation of surface chemistry and how the rocks and soil have "weathered" will tell us about the past climates. And the landers may find organic compounds or even evidence that tells us whether life was ever present on the surface of Mars; and if not, why not.

"Networks" of more than a dozen very small landers scattered over the planet could be used as weather stations to study Martian weather and the circulation of its atmosphere. If the network landers also have seismometers on board, and if they detect "Marsquakes," that information will tell us about what Mars is like deep in its interior, and how the interior has evolved over time. Mobility will be important for understanding the Martian surface and accessing features of particular interest, so missions involving long range rovers and balloons are being studied.

Finally, sample return missions can bring rocks and soil to laboratories on Earth for analysis by our most sophisticated instruments (too large and massive to send to Mars) which can tell us about the chronology of the planet's evolution, and may even allow us to detect compounds which could have led to life, or which are evidence of past life. (The odds of being able to select a rock with a fossil, however, are very low, even if fossils exist on Mars.)

Baseline Mission Set

All of these missions must be done within the very fight cost constraints of the Mars Exploration Program. The entire program over the next 10 years will be conducted for about one-third the cost of the Viking missions which orbited and landed on Mars twenty years ago. Each mission will cost about the same as a major motion picture, and the total cost of the first 10 missions to Mars will be about that of a single major military aircraft.

The Mars Science Working Group laid out a "strawman" strategy for fitting

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

the science goals into a set of missions which can gradually build up our knowledge of Mars over the next 10 years. This set of missions has evolved over the past year to that shown in Figure C-6. Figure C-6 shows the Mars launch opportunities from 1996 through 2005. The bottom half of the chart is the "U.S.-Only" component of the program, while the top half is actual or potential augmentation by international partners. The "baseline" missions are clear, with possible alternative missions or augmentation shaded. The numbers in parentheses are, respectively, the development cost, operations cost, and approximate launch costs of each year's mission set.

Mars Pathfinder will be the second mission in the series of NASA' s Discovery program of planetary exploration missions. It was launched in December 1996 on a McDonnell Douglas Delta II 7925 rocket (capable of throwing about 1000 kg to Mars). Mars Pathfinder will fly directly to Mars and plunge into the atmosphere at 17,000 mph without going into orbit. Using a combination of a heat shield, parachute, rockets and airbags, Pathfinder will land on the surface in an ancient flood plain which is expected to be littered with a wide variety of rocks. Pathfinder will image the Martian terrain in 13 different colors, monitor the weather, and deploy a small rover to explore the region around the lander and measure the composition of the surface.

Figure C-6

Mars Exploration Program strategy.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

Mars Global Surveyor, which was launched in November 1996 (also on a Delta II 7925), will go into orbit around Mars in September 1997. It will use "aerobraking," skimming through the upper part of the thin Martian atmosphere, to go from a long, looping orbit into a circular polar orbit. Mars Global Surveyor will scan the surface of Mars for a full Martian year (about two Earth years) using 6 of the 8 instruments that were originally flown on Mars Observer (which was lost in 1993—the first planetary spacecraft failure in 27 years).

Mars Global Surveyor is the first of a series of missions called the Mars Surveyor Program. This program will fly two missions to Mars every opportunity (about every 26 months), and, with Pathfinder, is pioneering the "better, faster, cheaper" approach to planetary missions. Through competitive procurements, Lockheed Martin Astronautics of Denver, Colorado, has been selected as JPL's industrial partner for Mars Global Surveyor, and for at least the subsequent set of Surveyor missions to be flown in 1998.

In late 1998, Mars Surveyor '98 will launch an orbiter and a lander on a Delta 7325 "Med-lite" launch vehicle. (The Med-lite will only throw about 565 kg to Mars, but is expected to cost considerably less than a Delta 7925.) The orbiter will carry a Pressure Modulator Infrared Radiometer (PMIRR) to map atmospheric temperature, water vapor, and dust over a full Martian year. This instrument was also previously flown on Mars Observer. The lander launched in 1998 will come to rest near the south pole of Mars and will carry a payload, including a robotic arm, which will excavate Martian history by trenching down through thin layers of dust (and possibly ice) deposited in the layered terrain. The polar lander will also chemically analyze the soil, including a search for organic molecules.

The final element of the lost Mars Observer payload (a gamma ray spectrometer) will search for water in 2001 on the Mars Surveyor '01 orbiter. Also to be launched in '01 is a lander which may explore the ancient highlands of Mars in areas where water is thought to have once flowed. The 2001 lander may analyze rocks to determine the ancient history of the climate and geology of Mars. The 2001 orbiter will be launched on a Delta 7325, but the lander may be launched on a new "Delta-lite" configuration which will reduce the lander's mass allocation. The 2001 mission may be conducted in partnership with the Russians, with the orbiter being launched on a Russian Molniya. This "Mars Together '01" launch would also include one or more Russian landers. A Russian lander could include a large rover, or perhaps two ''small stations" of the Russian Mars '96 mission type.

In 2003, the Mars Surveyor Program is exploring a partnership with the European Space Agency (ESA) to launch three U.S. landers carrying international payloads. These landers, plus a communication orbiter, provided by ESA, would be launched on a European rocket (Ariane 5). This joint NASA/ESA mission is called InterMarsNet. The landers would explore the interior of the planet using seismology to detect "Marsquakes," study geochemistry at three sites, and act as weather stations. In addition, a separate United States mission may be flown,

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

perhaps deploying a "network" of complementary and very small weather stations around the planet.

Mars Surveyor '05 mission may be the first in a series of missions to return samples from the Martian surface. Another possible sample return target is the Martian moon, Phobos. The Russians are especially interested in a Phobos sample return mission. Sample return missions, in general, will probably require violating some of the constraints of the Mars Surveyor program. They may be too expensive to be completely funded by the Mars Surveyor Program, and/or they may require violating the "two-launch" per opportunity rule. Therefore, these missions may be in partnership with the Russians and/or Europeans. A continuing program of robotic missions, including the return of samples, over ten years or so will pave the way for future human exploration.

New Technology Infusion

More instruments can be carried, or more landers and orbiters sent, if new technology improvements can be introduced into the U.S. spacecraft to make them smaller, lighter and cheaper. The Mars Pathfinder mission has introduced a new flight computer, based on the commercial IBM/Loral RS6000 computer, which will be the basis for the computers of a number of future planetary missions. This provides an enormous increase in computational power. Pathfinder is also utilizing a commercial operating system for its computer, and has pioneered a concurrently engineered flight/ground data system which has greatly reduced costs. Pathfinder has also pioneered a low cost entry and landing approach, of which all but the final airbag impact system is being baselined for future Mars missions. Mars Global Surveyor is utilizing a composite structure for the spacecraft, although its electronic systems and instruments are inherited from Mars Observer.

A program called "New Millennium" is currently being planned to develop and demonstrate the next generation of space technologies to reduce costs and improve performance for both planetary and Earth missions. The Mars Exploration Program will be a "customer" for this new technology, and some of the New Millennium demonstrations may "piggyback" on Mars missions. For 1998 the feasibility of the Mars Surveyor '98 lander carrying one or two New Millennium ''microlanders" to Mars is being studied.

Investment strategies are being developed by the Mars Exploration Program at JPL in partnership with Lockheed Martin, the New Millennium Program, and NASA's Office of Space Access and Technology (OSAT). Technology investment is required to shrink the '01 and '03 landers so that they are compatible with the limitations imposed by the Delta-lite launch vehicle, and the even more stringent limitations of the InterMarsNet mission. With the current InterMarsNet concept the U.S. landers must mass no more than 415 kg each, which means that the landers must decrease 150 kg from the 565 kg in 1998. Key technology advances are required to accomplish this mass reduction, while hopefully maintaining or increasing the payload fraction. These advances center around the electronics: an

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
×

advanced flight computer and memory, a small deep space transponder (X-band), light weight batteries, a high efficiency solid state power amplifier, advanced power electronics, and an inertial fiber-optic gyroscope.

In addition, because of the harsh environment on the surface of Mars, technology advances in temperature tolerant electronics and light weight insulation are required to enable long-term lander missions. The Pathfinder rover has pioneered an approach to light weight insulation using silica aerogel, however phase change materials are expected to be necessary for future missions.

The Pathfinder landing ellipse is about 70 by 150 km and its rover can only travel a few hundred meters. The lander mission in 2001 is expected to require much more accurate landing (<< 50 km landing ellipse) and considerable mobility (10s of km) to enable access to ancient lakebeds which may hold clues to the climate history of the planet. Advances in sample collection and storage, and in sample return technology (such as utilization of the atmosphere to manufacture fuel) will be required to enable low cost sample return by 2005.

Preparation For Human Missions

Each of the robotic missions in the Mars Exploration Program will be gathering information needed to plan future human missions to Mars. The robots will find and scout safe and interesting human landing sites, characterize the atmosphere and surface environments so that human missions can be designed properly, look for water and other resources needed by humans, and develop technologies (such as very low mass electronics) which will be important for human space flights to Mars.

Over the next couple of decades the robotic part of the Mars Exploration Program will result in a detailed understanding of Mars, which is of interest not only to scientists but to understanding more about the Earth's environment, and eventually, for future human exploration.

NASA is currently developing a long range "road map" for the human exploration of Mars. The road map builds upon the capability of the international space station to understand how people can live and work in space. Trips to Mars will utilize new launch vehicle technologies currently just beginning development, including re-usable and expendable rockets. The use of commercial technologies such as advanced electronics will greatly reduce the cost of human exploration of Mars. A current goal of this road map is to enable the first human Mars mission in 2018.

Humans on Mars, in partnership with robots, will explore the planet in more detail than robots alone can. Human presence may be required to finally answer the question of whether Mars has or once had life, and humans will seek to understand the implications of the answer to that question for the possibility of life elsewhere in the universe. Humans will utilize the resources of Mars to investigate how the planet can be made more easily habitable for future generations. And finally, our grandchildren may become citizens of Mars.

Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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Suggested Citation:"APPENDIX C: PAPERS SUBMITTED BY OPENING SESSION PRESENTERS." National Research Council. 1997. Reducing the Costs of Space Science Research Missions: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/5829.
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