Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

Abstract

The Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project has developed a suite of prototype sensors for enabling autonomous and safe precision landing of robotic or crewed vehicles on solid solar bodies under varying terrain lighting conditions. The sensors include a Lidar-based Hazard Detection System (HDS), a multipurpose Navigation Doppler Lidar (NDL), and a long-range Laser Altimeter (LAlt). Preparation for terrestrial flight testing of ALHAT onboard the Morpheus free-flying, rocket-propelled flight test vehicle has been in progress since 2012, with flight tests over a lunar-like terrain field occurring in Spring 2014. Significant work efforts within both the ALHAT and Morpheus projects has been required in the preparation of the sensors, vehicle, and test facilities for interfacing, integrating and verifying overall system performance to ensure readiness for flight testing. The ALHAT sensors have undergone numerous stand-alone sensor tests, simulations, and calibrations, along with integrated-system tests in specialized gantries, trucks, helicopters and fixed-wing aircraft. A lunar-like terrain environment was constructed for ALHAT system testing during Morpheus flights, and vibration and thermal testing of the ALHAT sensors was performed based on Morpheus flights prior to ALHAT integration. High-fidelity simulations were implemented to gain insight into integrated ALHAT sensors and Morpheus GN&C system performance, and command and telemetry interfacing and functional testing was conducted once the ALHAT sensors and electronics were integrated onto Morpheus. This paper captures some of the details and lessons learned in the planning, preparation and integration of the individual ALHAT sensors, the vehicle, and the test environment that led up to the joint flight tests.

Flight testing a Real-Time Hazard Detection System for Safe Lunar Landing on the Rocket-Powered Morpheus Vehicle

“…11,12 In addition, the team performed a large number of simulations in close cooperation with the Morpheus GN&C team to analyze and predict DEM coverage, safe site selection, number of HRN measurements, and timing performance for the planned Morpheus trajectory and flight dynamics. 13 In what follows we describe the performance of the HDS subsystems in more detail.…”

Imaging flash LIDAR for safe landing on solar system bodies and spacecraft rendezvous and docking

“…Figure 4 shows the lidar sensors mounted beneath the helicopter. 17 . These integration tests included three tethered tests during which the lidars were activated to communicate and provide data to various avionics systems while the Morpheus vehicle was suspended from a crane and executed a controlled flight procedure.…”

Advancing Lidar Sensors Technologies for Next Generation Landing Missions

“…The prototype lidar sensors were engineered to be as compact and robust as possible within the project budget and schedule constraints. Upon their completion, the prototype lidars were integrated with the HDS and AGN&C system and installed in an instrumented truck to conduct integration tests in a dynamic environment at the NASA-LaRC Lidar Test Range 9,10 . HDS uses the Flash Lidar images to generate a digital elevation map of the landing area and select the best landing location given the vehicle's constraints and the mission objectives.…”

“…11). The hazard field is a 100 m American Institute of Aeronautics and Astronautics x 100 m area simulating a challenging lunar terrain consisting of realistic hazard features (rock piles and craters) and designated landing areas 9 . The flight profile as shown in Fig.…”