Keith Morris, Lockheed Martin; Christopher Tamanini, Lockheed Martin
Keywords: GEO Satellite Characterization, Orbital Debris, Space Situational Awareness, Space Situational Awareness Policy, Space Traffic Management
Abstract:
Todays space environment is trending towards the cost-effective deployment of small satellites (SmallSats). Cube Satellites (CubeSats) have become a popular SmallSat platform of choice due to their low cost and increasing capability. CubeSat operations have steadily advanced from Low Earth Orbit (LEO) in 2003 to Geosynchronous Orbit (GEO) in 2019. The CubeSats small size along with the rapid nature of this expansion makes it increasingly difficult to maintain Space Situational Awareness (SSA) as CubeSats proliferate. This difficulty is magnified as CubeSats spread to GEO, given the satellites small size and GEO belts extreme distance from earth. One potential approach to this challenge is to expand the existing SSA system accordingly. This approach advocates for new capabilities and sensors, which are important, but will lead to excessive data collection and analysis, thus increasing cost. A more efficient option is to create operating guidelines that focus on a CubeSats design and operations within the GEO belt. This method ensures that CubeSats developers are utilizing standards during the design phase as well as standard operating procedures when on orbit to help minimize the load on the SSA system. This paper establishes an initial set of guidelines for utilizing CubeSats at GEO and recommends a path to implementation that will help maintain SSA around valuable assets in GEO.
Architectural analysis has been performed that identified several factors that can drive down the demands of the SSA system. The operational altitude in GEO is a major factor due to the unstable nature of the orbit. Following this, the tradeoff between fault tolerance and orbit regime is analyzed in detail. The stable Geopotential wells are examined as potential operating environments due to their unique phenomenology that traps low energy objects. CubeSat constellations are thoroughly reviewed, and specific operational criteria are established which differ from the operating guidelines of singular CubeSats. Potential requirements for providing position data are discussed, as publishing ephemeris could benefit the SSA community. Also, requirements for adding retro reflectors are examined alongside potentially having each CubeSat provide a unique self-identification signal. The specific focus of the GEO CubeSat operating guidelines as proposed encompass the following points:
Operate at -300km to +300km of the GEO belt
Operate with single fault tolerance to disposal when near GEO
Operation at the Geopotential wells for missions that support these locations
Operation of CubeSat constellations
Provide position and velocity data to the SSA community
Laser retro reflectors
Provide unique signal that identifies the satellite
In addition, other beneficial guidelines will also be examined such as standards for CubeSat parts testing, shared databases for GEO tolerant parts, coordination of maneuvers, scarring for potential debris removal systems, among others.
Implementing these CubeSat operating guidelines will require a minimum of time and effort from both satellite operators as well as SSA community members. With GEO being an international domain, the enforcement of these guidelines will be an important factor. The most expedient way to enact this change would be to gain recognition from a space oriented international governing body, who could facilitate discussion between industry, operators, and SSA community members that would allow the operating guidelines to be reviewed, enacted, and enforced. This governing body would facilitate agreement on the operating procedures from all associated stakeholders. Furthermore, a way to create/edit these guidelines would be established to respond to changing space conditions and new industry trends. Discussing, optimizing, and establishing these CubeSat operating guidelines will help maintain SSA of the GEO belt.
Date of Conference: September 17-20, 2019
Track: Space-Based Assets