Effects of the Solar and Space Environment on Technology and Society
Solar activity and Earth’s space environment can have deleterious effects on numerous technologies that are used by modern society. Understanding the origin of these effects is essential for the successful design, implementation, and operation of modern technologies. Not only will future research in solar and space physics address high-priority, frontier science objectives, but it will also provide key data and new understanding essential for protecting vulnerable systems against the harmful effects of the space environment.
CHALLENGES POSED BY EARTH’S SPACE ENVIRONMENT
While a number of schemes for long-distance communications had been proposed and even developed to some extent before the implementation of a practical electrical telegraph, it was the working model by Samuel F.B. Morse in 1835 that led to the first revolution in communications. Telegraph systems were installed rapidly in Europe and in the eastern United States after that, and the first successful transatlantic cable was laid in 1866. Shortly after the installation of several telegraph lines there were indications that the systems appeared to be detrimentally affected by external factors. Intervals of “spontaneous” electrical currents were often measured on the lines but were not understood. Less than a day after Richard Carrington first observed a white-light solar flare in 1859, commercial telegraph systems in New England and Europe experienced severe outages and even some sporadic operations without the benefit of their battery supplies. Telegraph systems used for military communications in the American Civil War suffered disruptions at times. Such events suggested that Earth’s environment, and perhaps even the Sun, caused these disturbances to telegraph systems. However, many scientists and telegraph engineers remained unconvinced for nearly a half century.
With the development in the late 19th and early 20th centuries of additional electricity-based technologies, including the telephone, it became increasingly apparent that the Sun was indeed the ultimate source of many telegraph and telephone system disturbances as well as of disturbances and outages in new technologies such as wireless communications and electrical power systems on local and larger geographical scales. Ironically, after the discovery of the ionosphere by Gregory Breit and Merle Tuve and by Edward Appleton, it also became evident that the Sun was the source of the ionization layer that facilitated early long-distance wireless transmissions, which had become especially important following Gulielmo Marconi’s demonstration of transatlantic transmissions in 1901.
When Arthur Clarke and then John Pierce suggested the use of Earth-orbiting satellites for communications, they did not anticipate that the environment of space would be anything but benign. However, the discovery of Earth’s charged-particle radiation belts by Van Allen in 1958 showed that this was not the case.
Concurrent with progress in spaceflight and in understanding of the space environment over the last four decades, increasingly sophisticated technologies have been developed and deployed on Earth and in space. What has been learned, often by hard experience, is that the space environment around Earth cannot be ignored in the design and operation of a wide range of systems and their components. Illustrated schematically in Figure 5.1 and listed in Table 5.1 are many of the processes occurring in space that can affect a large variety of ground- and space-based technologies.1,2
The harsh radiation environment of space is well recognized today, and all spacecraft—whether sent into orbit around Earth or to the far reaches of the solar system—must be designed to withstand the radiation environments that they may encounter. Anomalies produced by space radiation affect the operation of computer memory and processors aboard these spacecraft, and such anomalies seem to become more prevalent as semiconductor devices continue to shrink in size. Space radiation can also produce differential charging across spacecraft surfaces and in dielectric materials deep within the spacecraft itself, including cabling. If the charge buildup becomes large enough, electrical breakdowns (analogous to those caused by lightning discharges) occur that can damage sensitive electronic components and/or produce erratic signals in control lines.
In addition to the threat it poses to spacecraft systems, the radiation environment of space also poses risks for astronaut health and safety. Appropriate measures must thus be pursued to minimize the exposure of astronauts to particle radiation during geomagnetic storms and solar energetic
particle events. Solar energetic particle events could also be hazardous to the health of airline crews and passengers on polar routes.
While ionospheric disturbances have long been known to both facilitate and impair high-frequency wireless transmission and reception, such disturbances have also been found to interfere with transmissions to and from orbiting spacecraft using frequencies near a gigahertz and even higher. Such effects (generally “scintillation” of the signals—an effect that can be very disruptive) are found to be most severe in the equatorial and polar regions. Scintillation and other ionospheric disturbances are of serious
TABLE 5.1 Impacts of Solar-Terrestrial Processes on Technology
Induction of electrical currents in Earth
Malfunctioning of power distribution systems
Malfunctioning of long communications cables
Malfunctioning of pipelines
Interference with high-frequency communications
Interference with the Federal Aviation Administration’s wide area augmentation system
Interference with surveillance, over-the-horizon radars, and radar altimetry
Interference with geophysical prospecting
Enabler of geophysical prospecting
Interference with communications satellite signals scintillation
Magnetic field variations
Interference with attitude control of spacecraft
Interference with compasses
Solar radio bursts
Excess noise in wireless communications systems
Solar cell damage
Semiconductor device damage and failure
Faulty semiconductor devices
Spacecraft charging: degradation of surface and interior materials; production of electrical noise and disturbances
Risks to astronaut safety
Risks to airline crew and passenger safety
Micrometeoroids and space debris
Solar cell damage
Damage to mirrors, surfaces, materials, complete vehicles
Disturbanthe upper atmosphere
Interferth low-altitude satellite tracking and lifetimes
Attenuation and scatter of wireless signals
SOURCE: Adapted from L.J. Lanzerotti, Space weather effects on technologies, in Space Weather, Geophysical Monograph 125, P. Song, H.J. Singer, and G.L. Siscoe, eds., American Geophysical Union, Washington, D.C., 2001, pp. 11-22.
concern for military and civilian communications and navigation (e.g., for the use of single-frequency global positioning devices in applications that demand high precision.)
Although the telegraph with its extended network of lines and cables is an obsolete technology and the effects of the space environment on it are now irrelevant, solar-activity-induced disturbances still produce detrimental changes across other long conductors anchored to Earth, including pipelines, long-haul telecommunications lines, and glass-fiber systems that need electrical power for signal regeneration. Electrical power grids continue to
become more complex and interconnected, with the result that they have become more vulnerable to solar effects that disturb current systems in the ionosphere. Disturbed ionospheric conditions are accompanied by the heating of Earth’s upper atmosphere, which increases atmospheric density at the altitudes at which spacecraft in low Earth orbit, including the space shuttle and the International Space Station, fly. The increased density worsens drag on spacecraft, causing orbital perturbations that create tracking and operational difficulties and possibly even shortening mission lifetime through accelerated orbital decay.
The bursts of radio waves that accompany large outbursts of solar activity produce unwanted noise and interference in military communications and radar systems. With the burgeoning of the wireless telecommunications age over the last decade, more attention is now being given to the potentially adverse effects of solar radio bursts on these civilian systems as well. The vulnerability of wireless systems to solar activity depends sensitively on numerous design details and is a subject of considerable study.
The lesson learned over more than four decades is that the space environment presents many challenges for engineering and for science if many present-day and future technologies are to be successfully implemented. Moreover, these technical challenges are almost always intertwined with complex policy issues that can take a variety of forms. The following sections examine these issues, both technical and policy-related, in five key areas.
THE NATIONAL SPACE WEATHER PROGRAM
A key function of the National Space Weather Program is to develop processes and policies for monitoring the space weather environment. Technological changes are occurring at a very rapid pace in both large-scale systems and small-scale subsystems that can be affected by solar-terrestrial processes. This is true for both ground- and space-based systems. As an example, the electric power system in the United States is becoming ever more interconnected, through power sharing pools and other mutual arrangements. Such interconnectedness implies that a space-weather-related problem in one region could potentially cascade to a distant region not directly affected by the space weather event. As another example but at the opposite extreme of the size scale, rapid advances continue to occur in microelectronics and the miniaturization of circuits. There is also a continued drive toward the use of commercial off-the-shelf (COTS) components in military programs, including spaceflight programs, and toward including
more capabilities in civilian space programs, most importantly in communications satellites. The convergence of these trends (increased miniaturization and use of COTS components) could increase the vulnerabilities of both civilian and military systems.
An important step toward mitigating the adverse effects of solar activity and the space environment on important technological systems was taken by the United States in the mid-1990s when, following advocacy by researchers from academia, government, and industry, the National Space Weather Program (NSWP) was created.3,4 The focus of this program is on the entire Sun-Earth system, and its goal is “to achieve, within a ten year period, an active, synergistic, interagency system to provide timely, accurate, and reliable space environment observations, specifications, and forecasts.” The participating government agencies include the NSF (the lead agency), NASA, and the Departments of Commerce, Defense, Energy, and Transportation. The National Space Weather Program Council, consisting of high-ranking members of the agencies,5 oversees the NSWP. Following the creation of the NSWP, other studies and initiatives were carried out by several of the agencies, including the Space Weather Architecture Study by the DOD.6
Some of the agencies are also expanding their contacts and interactions with the external, predominantly university, research communities to tap the expertise residing there and to encourage research activities related to space weather. The DOD Office of Naval Research (ONR) and the Air Force Office of Scientific Research (AFOSR) initiated and now support three multidisciplinary university research initiatives, each of which is a 5-year program focused on developing physics-based assimilation models for the ionosphere, the magnetosphere, and the solar environment. The DOD-sponsored University Partnership for Operational Support, the goal of which is to develop space weather products for near-term use, is centered at the University of Alaska and the Johns Hopkins University.
The National Science Foundation has implemented a dedicated line of resources (augmented with funding from the AFOSR and the ONR) that is allocated by peer review for space weather studies. The agency also supports specialized workshops and activities related to space weather.
NASA has initiated the Living With a Star program to “develop scientific knowledge and understanding of those aspects of the connected Sun-Earth system that directly affect life and society.”7 The program includes four elements: (1) a space weather research network of solar-terrestrial spacecraft; (2) a theory, modeling, and data analysis program; (3) space environment testbeds for flight testing of radiation-hardened systems in the near-
Earth environment; and (4) the development of partnerships with national and international agencies involved with space weather concerns.
NOAA’s operational activities for space weather are centered at its Space Environment Center in Boulder, Colorado, where data are used and models are developed to aid in the forecasting and monitoring of solar-terrestrial conditions (see Figure 5.2). The Space Environment Center is the element of NOAA that is involved in defining continuing and new measurements and instruments for its civilian operational mission.
Over the last decade, a number of private companies have also become interested in issues related to space weather. This interest has often arisen as business extensions of related services that these companies had already been supplying to customers. As a result, some of these companies are beginning to provide space weather products to both private and public (including DOD) entities.
Finding: The federal agencies that have important research and/or mission interests in the solar-terrestrial environment are undertaking strong initiatives to establish, nurture, and evolve an effective national program in space weather. There is growing interest in the private sector in the provision of space weather products to both the private and the public sectors. As a result of all of these activities, numerous research and research policy issues have arisen that demand new attention from all parties interested in space weather.
MONITORING THE SOLAR-TERRESTRIAL ENVIRONMENT
Effective monitoring of the space environment requires identification of those research instruments and observations that are needed to provide the basis for modeling interactions of the solar-terrestrial environment with technical systems and for making sound technical design decisions. Considerable progress has been made in the last decade in understanding the effects of the space environment on Earth and its many technological systems. Ongoing and planned research will lead to further advances in the knowledge base. The vast majority of this research is motivated by intellectual curiosity. Not all of it is directly applicable to the products that potential users are calling for, nor should it be. The transfer of the results of basic research to practical use and products is one of the largest conundrums faced by technology managers and researchers. The converse relation, how the numerous puzzles and questions that arise from real-world problems can be used to influence research directions, also remains an issue.
A unique and nationally important aspect of solar and space physics research continues to be the rapid transition of new understanding of the Sun and the geospace environment to practical applications. This transition is especially important for federal agencies such as the DOD and NOAA. New research instrumentation deployed on the ground or in space often leads to major advances in new data capabilities that can be incorporated into applications and operational systems. Moreover, the continued acquisition of certain kinds of data by some existing facilities is important for operational purposes.
The responsibility for acquiring data on the solar-terrestrial environment is distributed among different agencies. For example, responsibility for maintaining the ground-based magnetometers, whose data are used for operational purposes by NOAA and the private sector, rests with the Department of the Interior. The space-based science platforms that serve the nation’s civilian space program are almost exclusively the responsibility of NASA. In both cases, as well as in the case of other facilities that perform virtually routine monitoring functions, the chief beneficiaries are NOAA’s operational programs. Transitioning such data acquisition programs and/or their acquisition platforms into operational use requires strong and effective coordination among agencies.
An example of a data acquisition activity that is of critical importance for both scientific and operational purposes and that raises questions of continued availability and of the transition from science to operations is the upstream monitoring of the solar wind and the interplanetary magnetic field. Currently, NASA’s Advanced Composition Explorer (ACE) spacecraft, located at the Lagrangian point L1, is providing key solar wind data used in NOAA’s operational programs and by private companies for their customers (see Figure 5.2). ACE is currently operating beyond its design life, however, and how such data are to be provided in the future will have to be seriously considered. International intentions and plans for L1 monitors will have to be taken into account as well. The future availability of interplanetary data, whether they come from L1 (these data provide some measure of early warning of disturbed conditions) or near Earth (these data can assess more accurately conditions that might affect Earth), always involves some uncertainty since the scientific peer review process does not normally give routine monitoring a high priority. Continuation of more routine monitoring of the geophysical environment by some ground facilities such as magnetometers and cosmic ray neutron monitors can be problematical as well, even when their usefulness for space weather applications is widely recognized.
Recommendation: NOAA and DOD, in consultation with the research community, should lead in an effort by all involved agencies to jointly assess instrument facilities that contribute key data to public and private space weather models and to operational programs. They should then determine a strategy to maintain the needed facilities and/ or work to establish new facilities. The results of this effort should be available for public dissemination.
Recommendation: NOAA should assume responsibility for the continuance of space-based measurements such as solar wind data from the L1 location as well as near Earth and for distribution of the data for operational use.8
Dramatic advances in understanding the causative links between CMEs and high-speed interplanetary streams and large geomagnetic disturbances have come from the solar remote-sensing instrumentation on the Yohkoh and SOHO spacecraft, both of which involve international collaborations. These advances have motivated the development of both the Solar Dynamics Observatory (SDO) and the STEREO mission. Imaging of key regions of geospace, such as the auroral zone, is now becoming more routine and therefore more useful for operational applications—for example, for monitoring and following electrojet activity, which can affect ground-based systems. There is now little doubt that imaging of the Sun and of geospace will one day play a central role in operational space weather forecasting.
Recommendation: NASA and NOAA should initiate the necessary planning to transition solar and geospace imaging instrumentation into operational programs for the public and private sectors.
Such transitions of other instrumentation have occurred over the years, from the addition of charged-particle sensors to operational weather satellites some years ago to the more recent incorporation of new concepts such as solar x-ray spectral and imaging data.
THE TRANSITION FROM RESEARCH TO OPERATIONS
An important task facing the space weather community during the coming decade will be to establish, maintain, and evolve mechanisms for the efficient transfer of new models of the solar-terrestrial environment into the user community. The mere acquisition of new knowledge, whether in the form of data sets or theoretical insights, is insufficient for practical uses.
Means must be established for transitioning the new knowledge into those arenas where it is needed for design and operations. Creative, cutting-edge research in modeling the solar-terrestrial environment has been under way in the research community for many years. Insofar as possible, these efforts use contemporary theoretical knowledge, current data sets, and, for some models and when data are available, real-time data for model validation and operational use. In recent years, proprietary models have also been introduced by private companies for use in both the public and private sectors.
Under the auspices of the National Space Weather Program, models thought to be potentially useful for space weather applications can be submitted to the Community Coordinated Modeling Center (currently located at the NASA Goddard Space Flight Center) for testing and validation. Following validation, the models can be turned over to either the U.S. Air Force or the NOAA Rapid Prototyping Centers, where they are used for the objectives of the individual agencies. DOD takes the research models and produces tailored products for its specific needs, while NOAA forecasts and specifies the solar-terrestrial environment.
In many instances, the validation of research products and models differs in the private and public sectors. In the private sector, validation generally occurs via the marketplace, when the customer pays for and uses the model or other product. The continued use and payment by the customer (government or private) tells the vendor that value has been added to the customer’s business. In contrast, publicly funded research models and system-impact products are usually placed in an operational setting with limited validation.
Recommendation: The relevant federal agencies should establish an overall verification and validation program for all publicly funded models and system-impact products before they become operational.
Over the years, the scientific community has developed many different models of the near-Earth space environment that could have practical applications. More recently, space environment models have been developed by commercial interests as well, with details of these private models often being proprietary. Public, nonclassified models now cover all of the near-Earth space domains, including the solar wind, magnetosphere, radiation belts, ionosphere, and thermosphere. Typically, for each domain, there are several different models developed by different individuals.
Recommendation: The operational federal agencies, NOAA and DOD, should establish procedures to identify and prioritize operational needs, and these needs should determine which model types are selected for transitioning by the Community Coordinated Modeling Center and the Rapid Prototyping Centers. After the needs have been prioritized, procedures should be established to determine which of the competing models, public or private, is best suited for a particular operational requirement.
DATA ACQUISITION AND AVAILABILITY
Developing successful space weather mitigation strategies involves the ability to predict space weather effects on specific technological systems as well as to predict space weather in general; it also requires a knowledge of extreme space environmental conditions. An oft-stated goal of researchers and those who use the results of the research is the ability to reliably predict the effects on geospace and specific technological systems following an event on the Sun. The “transfer functions” that relate a given solar observation to the effects on a specific technological system are largely unknown. For example, the vulnerability of an interconnected electrical power grid may depend on the location of a specific portion of the system relative to the instantaneous location of a suddenly changing electrojet current as well as on the conductivity of the ground beneath the system element.
The scintillations that might be encountered by a given radio transmission path can be highly variable depending on the state of the ionospheric plasmas and current systems in the path’s line of sight. Ionospheric current systems can be followed now in near-real time with appropriate instrumentation. However, forecasts of their movements and intensities and plasma properties from the data available are still primitive, to say nothing of the forecasts that might be derived from observations of conditions at the Sun and from subsequent solar wind measurements at L1. Related to this challenge is the need to identify existing databases that might provide a perspective on extreme conditions in the Sun-Earth system. Designing for operations under extreme conditions could be one way of relaxing space weather predictive requirements for implemented operational systems.
During the coming decade, gigabytes of data per day could be available for incorporation into physics-based data assimilation models of the solar-terrestrial environment and into system-impact codes for space weather forecasting and mitigation. The situation in solar and space physics regard-
ing data assimilation will then begin to resemble the state of data assimilation that exists today in meteorology. These solar and space physics data will be available for public codes, for national security codes, and for proprietary commercial codes. At present, there are several obstacles that hinder data assimilation. First, DOD traditionally uses its own data (which are often not available to outside users) and has only recently begun to use data from other agencies and institutions. Therefore, many data sets are not available for use by the publicly funded or commercial vendors that design products for DOD or would like to compete for product opportunities. In addition, the usefulness of data assimilation techniques will be unduly limited, since only a small fraction of the data is likely to be available in real time.
Recommendation: DOD and NOAA should be the lead agencies in acquiring all the data sets needed for accurate specification and forecast modeling, including data from the international community. Because it is extremely important to have real-time data, both space- and ground-based, for predictive purposes, NOAA and DOD should invest in new ways to acquire real-time data from all of the ground- and space-based sources available to them. All data acquired should contain error estimates, which are required by data assimilation models.
Implementation of this recommendation will require good coordination among agencies (see Chapter 7).
When designing ground- and space-based systems, engineers are typically interested in space climate and not space weather. Needed are long-term averages, the uncertainties in these averages, and values for extreme conditions. The engineering goal is to design a system to be immune to space weather effects as much as is feasible. That is, the space environment should be removed from the equation; any further space weather issues that might arise can be dealt with separately. When climatological models are developed, extreme conditions are either ignored or not properly represented because there are too few data points to justify including them in a statistical database.
Recommendation: A new, centralized database of extreme space weather conditions should be created that covers as many of the relevant space weather parameters as possible.
A possible location for the database is within NOAA, at its Space Environment Center or its National Geophysical Data Center. The database should primarily contain measurements, and resources will be needed to
search existing archives for the extremes for all relevant environmental parameters. The outputs of physics-based model runs for extreme conditions, appropriately documented and annotated, should be a part of the database.
THE PUBLIC AND PRIVATE SECTORS IN SPACE WEATHER APPLICATIONS
Both the government and private industry are involved in acquiring, assessing, and disseminating information and models related to the solar-terrestrial environment in the context of its relevance for technological systems. Therefore, it is important to determine the appropriate roles for each sector in space-weather-related activities. To date, the largest efforts to understand the solar-terrestrial environment and apply that understanding for practical purposes have been mostly publicly funded and undertaken by government research organizations, universities, and some companies. Recently, some private companies both large and small have been devoting their own resources to the development and sale of specialized products that address the design and operation of certain technical systems that can be affected by the solar-terrestrial environment. Such private efforts often use publicly supported assets (such as spacecraft data) as well as proprietary instrumentation and models. A number of the private efforts use proprietary system knowledge to guide their choices of research directions.
While some publicly and privately funded efforts are beginning to compete with one another to perform similar tasks, all parties recognize that synergistic benefits can occur through continuing collaboration and the clear definition of responsibilities among complementary organizations. Still, private-sector policies on such matters as data rights, intellectual property rights and responsibilities, and benchmarking criteria can be quite different from the policies that apply for publicly supported space-weather-related activities, including those performed at universities. Thus, transitioning knowledge and models from one sector to another can be fraught with complications and requires continued attention and discussion by all interested entities. Similar issues arise with regard to provision of public and private value-added meteorological data and data products,9,10 and lessons learned from the meteorology community can potentially be utilized as the national space weather effort grows, evolves, and matures.
Recommendation: Clear policies should be developed that describe government and industry roles, rights, and responsibilities in space
weather activities. Such policies are necessary to optimize the benefits of the national investments, public and private, that are being made.
The implementation of this recommendation should be led by NOAA and DOD, together with one or two commercial entities. The public sector might focus, for instance, on acquiring the real-time data needed for reliable forecasts as well as on the production of generic forecast information, while the private sector might focus on value-added, system-impact products, including forecast products that would be tailored to specific systems or missions. These policies could be developed in a variety of ways, one being to convene a study group or a workshop under the auspices of a third party.
Lanzerotti, L.J., et al., Engineering issues in space weather, in Modern Radio Science, M.A. Stuchly, ed., John Wiley & Sons, Inc., Hoboken, N.J., 1999.
Lanzerotti, L.J., Space weather effects on technologies, in Space Weather, Geophysical Monograph 125, P. Song, H.J. Singer, and G.L. Siscoe, eds., American Geophysical Union, Washington, D.C., 2001, pp. 11-22.
Office of the Federal Coordinator for Meteorological Services and Supporting Research, The National Space Weather Program: The Strategic Plan, FCM-P30-1995, Silver Spring, Md., August 1995.
Office of the Federal Coordinator for Meteorological Services and Supporting Research, The National Space Weather Program: The Implementation Plan, 2nd Edition, FCM-P31-2000, Silver Spring, Md., July 2000.
Robinson, R.M., and R.A. Behnke, The U.S. National Space Weather Program: A retrospective, in Space Weather, Geophysical Monograph 125, P. Song, H.J. Singer, and G.L. Siscoe, eds., American Geophysical Union, Washington, D.C., 2001, pp. 1-10.
National Security Space Architect, Space Weather Architecture Study Transition Strategy, March 1999. Available online at <http://schnarff.com/SpaceWeather/PDF/Reports/P-IIB/02.pdf>.
Withbroe, G.L., Living With a Star, in Space Weather, Geophysical Monograph 125, P. Song, H.J. Singer, and G.L. Siscoe, eds., American Geophysical Union, Washington, D.C., 2001, pp. 45-51.
For example, a NOAA-Air Force program is producing operational solar x-ray data. The Geostationary Operational Environmental Satellite (GOES) Solar X-ray Imager (SXI), first deployed on GOES-M, took its first image on September 7, 2001. The SXI instrument is designed to obtain a continuous sequence of coronal x-ray images at a 1-minute cadence. These images are being used by NOAA’s Space Environment Center and the broader community to monitor solar activity for its effects on Earth’s upper atmosphere and the near-space environment.
National Research Council, A Vision of the National Weather Service: Roadmap for the Future, National Academy Press, Washington, D.C., 1999.
Serafin, R.L., et al., Transition of weather research to operations: Opportunities and challenges, Bulletin of the American Meteorological Society 83, 377-392, 2002.