Reconstruction of Entry, Descent, and Landing Communications for the InSight Mars Lander

Abstract

The Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on 26 November 2018 to conduct an exploration of the interior of Mars. To meet NASA’s requirement for communications during critical events, the InSight lander transmitted telemetry continuously throughout entry, descent, and landing. This allowed the public to witness the landing in real time. The transmissions were received by five assets: three at Mars and two on Earth. These included real-time relay of telemetry by the first deep-space CubeSats. This paper describes the constraints on the design of an entry, design, and landing communication link; the uncertainties in the trajectory; and the modeling that was used to meet these constraints. It then reports on the actual performance of each link, including an unexpected degradation of signal to the Mars Reconnaissance Orbiter. The lessons learned from this process contributed to the successful relay of data from the Perseverance lander, as well as to the design of future landing communications systems.