KNI-MDL Seminar

Regolith-Plume Interaction: An Engineering Challenge for Exploration-Ryan Hurley, Caltech

Regolith is the sand or soil found on the surface of many celestial bodies, including planets, moons, and asteroids. When rockets carrying an exploratory vehicle descend toward a soil-covered body, a complex and dangerous interaction between regolith and rocket-expelled gas plumes can occur. Regolith erosion becomes a projectile and visual hazard, endangering equipment and interfering with important sensors. This talk addresses some of the challenges associated with regolith-plume interaction, highlighting the work that has been performed on this problem since the 1960s. A new modeling approach will be discussed that attempts to capture much of the important physics of the problem in a unified way. This modeling approach has significant applications beyond the regolith-plume problem, into the larger field of soil-fluid interaction.

Technologies for Next Generation Entry, Descent, and Landing (EDL)-Aron Wolf, JPL

JPL has steadily advanced the EDL state of the art from Viking in the 1970's through the Mars Science Laboratory (MSL) which landed in 2012, improving landing accuracy and increasing landed mass, most recently delivering the 900-kg MSL rover to within a ~10km x ~4 km landing ellipse. Landing accuracy, mass, and site elevation capability are critical performance metrics for the Mars Sample Return campaign, which was ranked as the highest priority of NASA's robotic planetary exploration program in the 2011 Decadal Survey. Improving these metrics is a long-term goal of the Mars Program to allow landing increasingly sophisticated payloads safely in areas of greater scientific interest populated by hazards, and reducing rover traverse distance and design complexity (hence total mission cost and risk). Improved modeling of the interaction of rocket exhaust with the planet's surface is also being pursued as a risk-reduction measure, due to concerns noted in MSL's landing about degradation of the critical ability of the radar to measure velocity due to dust plumes shortly before touchdown.