When NASA and other agencies send landers to Mars and other planets, they rely on existing orbiters to relay the data during the critical entry, descent, and landing (EDL) phase. The current orbiters are aging and there are no current NASA plans to replace them. Future landers have a critical challenge to communicate during a very risky mission phase. The InSight mission will land on Mars in September 2016 with no direct-to-Earth radio link. Instead, Insight expects the Mars Reconnaissance Orbiter (MRO) to be fully functional and placed in an orbit to be in view of the EDL time and place. MRO will take many hours to play back the data to Earth, leaving the project staff without knowledge if their valuable spacecraft has made it safely.

Artist drawing of a proposed Mars communications relay utilizing CubeSats. A lander such as the InSight mission transmits landing telemetry at UHF that the CubeSats receive at relay at X-band to the Deep Space Network in real time.
A solution to this challenge is to have the mission in need of relay assets carry CubeSats (very small spacecraft) on the same launch vehicle that could also travel to the same destination and place themselves in view of the EDL place and time. The CubeSats would be equipped with the needed radio system to receive the EDL signal at UHF from the lander and transmit at Xband to Earth.

The novelty of this proposed concept is called “carry your own relay.” It solves a very critical communications problem in the robotic solar system exploration for NASA and JPL. New missions, instead of having critical dependencies on other spacecraft to carry out the radio relay process for them, could each carry their own relay, which are low mass, low power, and low cost.

This work directly relates to current and future NASA missions of solar system exploration by solving a communications relay problem. Once demonstrated in space, other future missions requiring relay from any target in the solar system can benefit from this invention, provided the CubeSat can meet the data rate and volume requirements with suitably chosen RF or optical communications technologies. This innovation has applications in future NASA and foreign space agency missions to deep space, especially assets that land (rovers, parachutes, probes) that require a communications relay. With current technology, these CubeSat (or small spacecraft) relay systems are especially applicable to relatively short critical event coverage with relatively low data rate requirements.

This work was done by Sami W. Asmar of Caltech for NASA’s Jet Propulsion Laboratory. NPO-49544