NASA's Autonomous Landing Hazard Avoidance Technology (ALHAT) project recently completed its third free-flight test on the Morpheus prototype lander April 30, demonstrating its ability to navigate and determine safe landing sites on planetary surfaces.
Led by engineers at NASA's Johnson Space Center in Houston and supported by Langley Research Center in Hampton, Va., and the Jet Propulsion Laboratory in Pasadena, Calif., ALHAT technology will provide planetary landers similar to Morpheus the ability to precisely and safely land on rugged surfaces by detecting dangerous hazards such as rocks, holes and slopes.
During the 94-second test, the Morpheus vehicle took off in a cloud of dust from its launch pad just off the Shuttle Landing Facility runway at NASA's Kennedy Space Center in Florida. It ascended to 807 feet (nearly 246 meters) and then began its powered descent toward the ALHAT hazard field 1,327 feet (roughly 404 meters) downrange.
During descent, Morpheus flew a route similar to that of an actual lunar lander while actively making measurements with ALHAT's three Light Detecting and Ranging, or lidar, sensors: the flash lidar, Doppler lidar and high-altitude laser altimeter. Since all three sensors use lasers, they can provide measurements in all lighting conditions.
The first sensor, the flash lidar, created an elevation map of the hazard field to identify the location of rock piles and craters. The second sensor, the Doppler lidar, was used to provide Morpheus with range and velocity data of its position relative to the landing surface. Lastly, the high-altitude laser altimeter provided altitude measurements that helped the vehicle initially locate the surface and land safely.
"During the last free flight test, the ALHAT sensors provided some of the best measurements yet, and the vehicle landed at the location that the ALHAT Hazard Detection System selected, which was another first for the system," said Langley engineer Kevin Kempton.
Testing will resume in May, when ALHAT will forgo the help of Morpheus' navigation by using only the measurements of the sensors to land the vehicle on the hazard field.
"A successful demonstration will open the gate for ALHAT technologies to be used on the next set of lander missions," Kempton said.
The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages ALHAT and Morpheus. Advanced Exploration Systems pioneers new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit.