Janus and Lunar Trailblazer: Lockheed Martin Deep Space SmallSats for NASA SIMPLEx Missions

NASA’s Small Innovative Missions for Planetary Exploration (SIMPLEx) program is a principal investigator-led planetary science program focusing on small spacecraft. In the SIMPLEx-2 opportunity, the cost cap for SIMPLEx missions is approximately 1/10th the cost of the next larger class of planetary exploration missions, the Discovery Program. Unlike Discovery missions, SIMPLEx missions launch as rideshare payloads with other NASA primary missions. Lockheed Martin has developed a science-capable deep space small spacecraft architecture to support two missions selected for the SIMPLEx-2 opportunity: Janus and Lunar Trailblazer. Janus is a two-spacecraft mission to fly by two different binary Near Earth Asteroids, partnered with Dr. Dan Scheeres at the University of Colorado Boulder. Lunar Trailblazer is a lunar orbiter led by Dr. Bethany Ehlmann at Caltech which will map water on the Moon; both have passed PDR and are confirmed for flight. Janus will launch first, in August 2022. A scalable suite of hardware subsystems enables the same low-cost spacecraft architecture to support both missions with a high degree of commonality, despite their disparate mission designs, environments, physical configuration, and science operations. As both missions move through project implementation, the management and engineering teams have learned valuable lessons for developing deep space-capable small spacecraft, adapting from both Earth-orbiting SmallSats and traditional larger planetary exploration missions in the Discovery and New Frontiers program classes. Key lessons learned include the value of early and close coordination between interested science teams and spacecraft providers, the need to tailor the complexity of science investigations to SmallSat spacecraft capabilities, the importance of evaluating component lifetimes against the deep space mission environment, and the challenge of planetary mission design to a rideshare launch. Rideshare missions on planetary launches must meet schedules determined by primary spacecraft with inexorable planetary launch windows and must provide enough propulsion to reach their own destinations which may include planetary orbit insertion or targeting a completely different solar system destination than the primary spacecraft.