Basic Spacecraft Subsystems (Source: Nelson and Lenehan)

Low-Impact Space Weather Sensors and the U.S. National Security Spacecraft

Incorporating inexpensive, low-impact, targeted surface charging (plasma) and total ionizing dose (radiation) sensors onto national security spacecraft to monitor real-time environments local to each spacecraft will close a gap in the U.S. space weather observation network.

The objective of this research was to explore the potential benefits of equipping U.S. national security spacecraft with low-impact and inexpensive targeted space environment sensors, review the systems engineering and acquisition challenges that exist in executing this proposal, and provide recommendations for overcoming these challenges to meet the needs of national security space.

In the earliest days of space exploration, the Soviet’s Sputnik 2 and the United States’ Explorer 1 observed the earth’s magnetic field and its trapped charged particles, now known as the Van Allen radiation belts. As the number of spacecraft in orbit increased, so did the United States’ understanding of space weather and its effects on technology. Today, it is understood that “energetic particles and plasma in the space environment can be hazardous to space systems, causing system outages, shortening mission lifetimes, reducing functional capabilities, and potentially masking hostile actions”. Despite these known threats, “the ability to observe, predict, and warn of impending solar activity is in its childhood”.

The United States is limited in its ability to understand current environmental conditions in space and forecast space weather and its effects partly due to the relatively small number of environment sensors currently in orbit. Two classes of sensors are employed to track the near-earth space environment: (1) Targeted sensors capable of measuring the environment and effects at a level sufficient for providing situational awareness for the host spacecraft; and (2) comprehensive sensors capable of providing detailed environmental measurements that can be mapped to a broad region of near-Earth space, providing global situational awareness and quantitative characterization of the environment.

Additionally, due to the lack of space weather situational awareness, determining if environmental factors contributed to an on-orbit spacecraft anomaly is “time- consuming, inaccurate, and of a low confidence level”. Finally, U.S. national security is increasingly dependent on the capabilities of space systems.

Space is now a recognized domain of warfare. In this increasingly contested environment, “real-time, spatially accurate space environment data from a targeted sensor is critical to determining whether a specific anomaly event might be the result of hostile activity rather than natural phenomena”.

National security space system development, deployment, and operations would benefit greatly from improved space environment situational awareness; however, at this time, a comprehensive strategy to improve U.S. capabilities has not been approved. Sensor technology is at a readiness level that accommodates multiple targeted sensors incorporated onto the spacecraft structure with minimal impact to the host. Currently, monitoring the environment around individual spacecraft is rarely a requirement. Without a requirement, program managers are not able to invest in this capability despite the known benefits.

To overcome these challenges, a low- to no-cost schedule impact integration plan is recommended. This strategy will allow the spacecraft operators to benefit immediately from the data provided by targeted spacecraft sensors. Over time, it will improve the general understanding of the space radiation and plasma environments over all orbital regimes where national security spacecraft operate.

This comprehensive amalgamation of targeted spacecraft sensors will improve space weather models that influence both space weather forecasting and spacecraft design. These immediate and comprehensive improvements to the understanding of the space environment will allow space operators to respond proactively to space weather threats, differentiate between space weather and adversarial impacts, and allow spacecraft designers to engineer spacecraft with more accurate margins to survive space weather effects. These benefits ultimately improve spacecraft operational availability and space weather monitoring resiliency and will help drive down spacecraft cost.

This work was done by Dennis R. Olson for the Naval Postgraduate School.For more information, download the Technical Support Package (free white paper) below. NPS-0015

This Brief includes a Technical Support Package (TSP).
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Low-Impact Space Weather Sensors and the U.S. National Security Spacecraft

(reference NPS-0015) is currently available for download from the TSP library.

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