Flight Testing ALHAT Precision Landing Technologies Integrated Onboard the Morpheus Rocket Vehicle

Abstract

A suite of prototype sensors, software, and avionics developed within the NASA Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project were terrestrially demonstrated onboard the NASA Morpheus rocket-propelled Vertical Testbed (VTB) in 2014. The sensors included a lidar-based Hazard Detection System (HDS), a Navigation Doppler Lidar (NDL) velocimeter, and a long-range Laser Altimeter (LAlt) that enable autonomous and safe precision landing of robotic or human vehicles on solid solar system bodies under varying terrain lighting conditions. The flight test campaign with the Morpheus VTB involved a detailed integration and functional verification process, followed by tether testing and six successful free flights, including one night flight.The ALHAT sensor measurements were combined within a specialized ALHAT Navigation filter that was employed in closed-loop flight testing within the Morpheus Guidance, Navigation and Control (GN&C) subsystem. Flight testing on Morpheus utilized ALHAT for safe landing site identification and ranking, followed by precise surface-relative navigation to the selected landing site. The successful autonomous, closed-loop flight demonstrations of the prototype ALHAT system have laid the foundation for the infusion of safe, precision landing capabilities into future planetary exploration missions.

Kinematic Approximation of Position Accuracy Achieved Using Optical Observations of Distant Asteroids

“…These ambitious objectives are driving significant investment in autonomous navigation technologies that ensure accurate terminal delivery of the spacecraft to its target. Major autonomous navigation efforts are currently underway to support asteroid and comet sample retrieval [8], soft landing on planets and large moons [9][10][11][12], hazardous asteroid deflection [13], formation flying [14], and onorbit rendezvous between spacecraft [15][16][17].…”

Open-Loop Flight Testing of COBALT Navigation and Sensor Technologies for Precise Soft Landing

“…The COBALT altitude and velocity are also roughly double what was attained for ALHAT testing onboard the Morpheus vehicle. 15 The Xodiac vehicle made its first free flight in 2016, and subsequent MSS envelope expansion flights On takeoff, the vehicle performs a vertical ascent to reach the peak 500-m altitude, followed by a vertical descent with reduced engine thrust to achieve a 25 m/s downward velocity. At maximum downward velocity, a 300 meter lateral divert maneuver is planned onboard and executed to target a pre-determined, down-range landing location.…”

COBALT: Development of a Platform to Flight Test Lander GN&C Technologies on Suborbital Rockets

“…The ConOps for COBALT was developed to expand the flight test envelope for the NDL, compared to prior flight tests onboard the NASA Morpheus vehicle, 7 and to test the performance of a precision navigation filter that incorporates both NDL and LVS measurements. The ConOps ( Figure 10) also builds upon the prior ADAPT ConOps, with increases to altitude and vertical descent speed based on the new Xodiac vehicle performance capabilities with the COBALT payload.…”