NASA’s Innovative Advanced Concepts (NIAC) program selected Interplanetary CubeSats for further investigation, some results of which are reported. Interplanetary CubeSats enable small, low-cost missions beyond LEO. This class is defined by mass <~ 10 kg, cost < $30M, and durations up to 5 years. Over the coming decade, a stretch of six distinct technology areas, creating one overarching architecture, can enable comparatively low-cost Solar System exploration missions with capabilities far beyond those demonstrated in small satellites to date.
1. CubeSat electronics and subsystems extended to operate in the interplanetary environment (esp. radiation and duration of operation).
2. Optical telecommunications to enable very compact, low power uplink/downlink over interplanetary distances.
3. Solar sail propulsion to enable major maneuvers and rendezvous with multiple targets using no propellant.
4. Navigation of the Interplanetary Superhighway to enable multiple destinations over reasonable mission durations with achievable delta-V.
5. Small, highly capable instrumentation (such as a miniature imaging spectrometer) enabling acquisition of high-quality scientific and exploration information.
6. Onboard storage and processing of raw instrument data and navigation information to enable maximum utility of uplink and downlink telecom capacity, and minimal operations staffing.
When integrated, these technologies form the Interplanetary CubeSat Architecture.
Architecture: Interplanetary CubeSats build on the existing Earth-orbiting CubeSat architecture. Target spacecraft volume is 10 cm x 20 cm x 30 cm (6U). 2U are reserved for the mission-specific payload. The solar sail occupies 2U and deploys to form a 6 x 6 m or larger square. The solar sail is based on the Planetary Society/Stellar Exploration LightSail™ 1, plus electrochromic tips for attitude control. A 2-way optical communication terminal occupying 1U is based on JPL laser telecommunications developments, with a link capacity of 1 kbps @ 2 AU Earth-spacecraft distance. The final 1U is used for satellite housekeeping (C&DH, power, attitude determination) and based on CalPoly CP7 and JPL CubeSat On-board processing Validation Experiment (COVE) avionics.
Candidate missions: Though there are many different missions that would be possible with this architecture, the potential missions being researched under NIAC sponsorship are:
1. Mineral Mapping of Asteroids
2. Solar System Escape Technology Demonstration
3. Earth-Sun Sub-L1 Space Weather Monitor
4. Phobos Sample Return
5. Earth-Moon L2 Radio Quiet Observatory
6. Out-of-ecliptic Missions
Objectives and technology drivers of these missions are reported to illustrate the broad spectrum of missions enabled by advancing the CubeSat state-of-the-art beyond low Earth orbit.