1
Introduction
BACKGROUND
Laboratory Research in Space
NASA’s Office of Biological and Physical Research1 funds research that is concerned with the effects of reduced gravity on physical, chemical, and biological phenomena. The various phenomena studied, on which gravity can have a profound effect, range from smoldering combustion to bone loss in humans. The goal of such research is generally to use reduced gravity as a tool to gain a better understanding of these fundamental phenomena, many of which are also important to a range of industrial processes. Such knowledge not only contributes to several fields of basic science, but is also needed to enable the development of countermeasures for microgravity-induced changes in astronaut physiology as well as improved spaceflight technologies. Given that it is not practical in this brief report to describe the various areas of research, the reader is referred instead to previous NRC reports (NRC, 1995, 1998, 2000) that detail the research and accomplishments in the discipline programs and recommend specific research priorities.
In the absence of a permanent laboratory in orbit, there are basically four ways to carry microgravity life and physical sciences investigations into space. There are mid-deck lockers in the crew cabin of the shuttle, but their volume is small2 and they are severely limited in number for any particular flight. Until 1998 there was the Spacelab module, which provided significant volume, power, crew access, and standard lab facilities for longer experiments. In addition, there is the commercial SPACEHAB facility, which provides a research volume between the volumes of the first and second options. And finally, there are free-flyers (essentially unmanned satellites launched into a temporary orbit lasting days to months), which are limited to carrying fully automated experiments. Unlike the first three methods, however, free-flyers do not permit research studies that rely on the use of human subjects and/or require crew intervention to conduct the investigations.
Successfully completing a mission to support a group of scientific investigations requires a long period of preparation in advance of the flight, adequate research funds, flight-qualified research hardware, and a well-trained crew to perform in-flight research activities. Flight opportunities are also limited by competition for shuttle manifest slots for other purposes, most notably flights to support the assembly,
outfitting, and maintenance of the International Space Station (ISS) itself. Consequently, when considering whether to add non-ISS flight opportunities, NASA must weigh the benefits of providing continuing flight research opportunities to nurture, develop, and sustain a research community that will be ready to use the ISS against the benefits of completing the assembly of the ISS on schedule and within budget.
The International Space Station
The space station has been officially under development by NASA since the late 1980s. During that time, the scope of the effort has been reevaluated, resized, and redistributed several times, with perhaps the largest rescoping of the design occurring in 1992–1993. At that time NASA distributed some of its costs and development responsibilities among several international partners in exchange for research time and resources aboard the ISS. As a result of changes in both the design of the ISS and its schedule for development, it has been necessary for NASA to reexamine repeatedly the station’s ability to support its promised goal of “world-class research” in both the biological and physical sciences. NASA noted as follows in “International Space Station Familiarization: Mission Operations Directorate Space-Flight Training Division,” July 31, 1998, available on its Web site:
The purpose of the ISS is to provide an earth orbiting facility that houses experiment payloads, distributes resource utilities, and supports permanent human habitation for conducting research and science experiments in a microgravity environment (ISSA IDR no. 1, Reference Guide, March 29, 1995). This overall purpose leads directly into the following specific objectives of the ISS program:
-
Develop a world-class orbiting laboratory for conducting high-value scientific research.
-
Provide access to microgravity resources as early as possible in the assembly sequence.
-
Develop effective international cooperation.
-
Provide a testbed for developing 21st Century technology.
The changes in schedule and cost projections throughout the 1990s have prompted reevaluations of the number and scale of the major facilities that would eventually be placed on board; the schedule for developing, deploying, and utilizing those facilities; and the critical resources such as crew time and electrical power needed to support ISS science research.
Specific concerns over schedule delays and potential downgrading of ISS research capabilities have been growing for several years in the scientific community (Sigler et al., 2000) and have been cited in a number of NRC reports reviewing space laboratory sciences (NRC, 1992, 1997, 1998). More recently, internal scientific committees that advise NASA at various organizational levels have voiced considerable alarm at the possibility of further reductions in ISS science support capabilities (Sekerka, 2001; Fettman, 2001; Katovich, 2001). In the fall of 2000, Congress directed that the National Research Council and the National Academy of Public Administration (NAPA) should organize a joint study of the status of microgravity research in the life and physical sciences as it relates to the ISS. As detailed in the preface, the study is being conducted in two phases. For this phase-1 report, the NRC was asked to address the questions of the state of readiness of the scientific community to use the ISS for life and physical sciences, and to work with NAPA on an assessment of the relative costs and benefits of dedicating a yearly space shuttle mission for research versus simply maintaining the current schedule for assembly of the ISS.
TABLE 1.1 Comparison of Research Support Capabilities for Rev. F and Proposed Rev. G
|
Research Support Capability |
Rev. F |
Proposed Rev. G |
|
Number of crewa |
6 to 7 |
3 |
|
Total power |
110kWb |
73kWc |
|
34.4 m3 |
20m3 |
|
|
Number of research racksd |
27 |
|
|
NOTE: Data taken from various NASA briefings. aNASA currently estimates a minimum of 2.5 crew required for maintaining the ISS, exclusive of any science-related duties. bForty-five kilowatts would be available for research. cObtained by subtracting the power provided by the Starboard Photovoltaic Array deleted in NASA’s Rev. G Assembly Sequence. As this report was going to press, there were indications that the array might be reinstated. dU.S. share. eNumbers based on NASA estimates of 0.5 m3 of research volume for each EXPRESS rack and 1.6 m3 of research volume for international standard payload racks (ISPRs). EXPRESS rack volume is less than in ISPRs due to volume used by mid-deck locker hardware. fBoth volumes are reduced if ISPRs for freezers and the window observation facility are discounted. gRacks eliminated are the habitat holding rack 2, fluids and combustion facility 2, fluids and combustion facility 3, materials science research facility 2, materials science research facility 3, commercial materials, biotechnology facility, x-ray diffraction system, and advanced human support technology. hNote that the table does not include data on the experiment modules also eliminated in proposed Rev. G. |
||
Subsequent to the initiation of this study, NASA announced large projected cost overruns in the construction of the ISS. As a consequence, major changes were proposed in the most recent official ISS design, which NASA refers to as Rev. F,3 that would reduce the total ISS crew capacity from six or seven to three, reduce the station’s electrical power, and cancel or delay indefinitely the development and deployment of many of the planned major research facilities. (Table 1.1 compares Rev. F with the restructured ISS, called “proposed Rev. G”4 in this report.) The likely impact of these changes on the ability of the ISS to support science research would be severe. It was necessary, therefore, for the task group to make adjustments during the course of the study to accommodate both the possibility of a rescoped station and the uncertainty regarding the extent of such a rescoping. In the chapters that follow, this report outlines both the approach taken by the task group to deal with these uncertainties and the conclusions it developed.
REFERENCES
Fettman, Martin J. 2001. Letter to Joel Rothenberg on funding for the Space Station Biological Research Project. Colorado State University, College of Veterinary Medicine and Biomedical Sciences. March 9. Photocopy.
Katovich, Michael J. 2001. Letter to the Honorable Barbara A.Mikulski on funding for the Space Station Biological Research Project. University of Florida, College of Pharmacy. June 28. Photocopy.
National Research Council (NRC), Space Studies Board. 1992. Letter Report: On the Space Station Freedom Program. Available online at <http://www.nationalacademies.org/ssb/freedom921tr.htm>.
NRC, Space Studies Board. 1995. Microgravity Research Opportunities for the 1990s. Washington, D.C.: National Academy Press.
NRC, Space Studies Board. 1997. “On Research Facilities Planning for the International Space Station,” letter from SSB Chair Claude R.Canizares, Committee on Space Biology and Medicine Chair Mary Jane Osborn, and Committee on Microgravity Research Former Chair Martin E.Glicksman to NASA Administrator Daniel S.Goldin. July 8.
NRC, Space Studies Board. 1998. A Strategy for Research in Space Biology and Medicine in the New Century. Washington, D.C.: National Academy Press.
NRC, Space Studies Board. 2000. Microgravity Research in Support of Technologies for the Human Exploration and Development of Space and Planetary Bodies. Washington, D.C.: National Academy Press.
Sekerka, Robert F. 2001. Letter to the Honorable Barbara A.Mikulski on the level of ISS research funding. Carnegie Mellon University, Department of Physics. June 27. Photocopy.
Sigler P.B., G.S.Stein, A.L.Boskey, N.D.Jones, J.Kuriyan, W.M.Miller, M.L.Shuler, and B.C.Wang. 2000. Cell science and protein crystal growth research for the International Space Station. Journal of Cell Biochemistry 79(4):662–671.
