Abstract: Prior mars rover missions have all landed in flat and smooth regions, but for the Mars 2020 mission, which is seeking signs of ancient life, this was no longer acceptable. To maximize the variety of rock samples that will eventually be returned to earth for analysis, the Perseverance rover needed to land in a geologically diverse region with exposed layers. Terrain relief that is ideal for the science obviously poses significant risks for landing, so a new landing capability called Terrain Relative Navigation (TRN) was added to the mission.  TRN takes images of the ground during parachute descent and matches them to a map of the landing area made from orbital imagery.  These matches provide a position fix, like GPS, that tells the lander where it is relative to a map of known landing hazards.  Given its position relative to the hazards the spacecraft can identify a safe and reachable landing site to target during the final rocket powered phase of landing. This talk will describe the scientific goals of the mission, the Terrain Relative Navigation system design and the successful results from landing on February 18^th, 2021.

BioSketch: Dr. Andrew E. Johnson is a Principal Robotics Systems Engineer in the Guidance and Control Section of the NASA Jet Propulsion Laboratory.  Since joining JPL in 1997, he has been developing technologies and flight systems for autonomous navigation and mapping during descent to planets moons, comets and asteroids. For the Mars Exploration Rovers, he was lead developer for the Descent Image Motion Estimation System, and on Mars 2020 he led the development of the Lander Vision System that provided surface relative position estimates for Terrain Relative Navigation. He was also the manager of the Mars 2020 Guidance Navigation and Control subsystem which included cruise, EDL and surface mission functions.  Andrew received undergraduate degrees in Mathematics and Engineering Physics from the University of Kansas and a Ph.D in Robotics from Carnegie Mellon University.

https://mars.nasa.gov/mars2020/mission/overview/

https://mars.nasa.gov/mars2020/mission/technology/#Terrain-Relative-Navigation

Host: Martial Hebert

For Appointment Contact: Stephanie Matvey (smatvey@andrew.cmu.edu)