Advanced Lunar Lenders now will be able to automatically identify and navigate to a safe landing location, while detecting hazards in landing during final descent to surface. NASA is developing an advanced technology for lunar lenders that made them capable to land safely near resources located in potentially hazardous area.
Critical Sensor Technology
NASA's Langely Research Center has developed two critical sensor technologies. One is a three-dimensional active imaging device that measures topography of a landing area. The second device measures speed to help land precisely at the chosen site.
Langely Research Center has designed two special purpose light detection and ranging sensors to make these two devices. In addition to this Jet Propulsion Laboratory of NASA is developing certain algorithms to analyze the terrain based upon these lidar measurements.
These technologies have been integrated as part of Autonomous Landing and Hazard Avoidance Technology (ALHAT) project of NASA. These technologies are in the phase of demonstration and testing in a series of flight tests.
Bob Reisse
Bob Reisse is leading the team at Langley Research Center which is designing the lidar sensors and supporting the demonstration flight tests.
They have conducted two demonstration flights and Reisse says, "We were pleased that the two flight tests we've conducted so far have resulted in better than expected performance of these sensors."
Two Phases Of Demonstration Flights
First test that was carried out in May, was to The main objective of the first test, carried out in May, was to demonstrate the application of 3-D imaging technology or 'flash' lidar, for topography mapping and precision navigation.
Second demonstration in August was to of flight tests, completed in August, was to evaluate the capabilities of an emerging lidar technology developed at Langley. This lidar provides vehicle velocity vector, altitude and attitude with a very high degree of precision.
Demonstration Test Procedures
In the recent demonstration test the velocimeter was carried aloft at Dryden Flight Research Center of NASA via helicopter which flew a total of six flights at various altitudes between targeted reference points.
During the demonstration tests, the helicopter flew over two target areas three miles (5 km) apart on the surface of Rogers Dry Lake. Repeated back-and-forth tracks were flown at altitudes incrementally increasing from about 300 feet to 6,200 feet (91m to 1,890m) above the lake bed while the lidar measured the relative speed, altitude, and attitude of the helicopter. Plywood circles placed on the lakebed served as reference targets for determining the ground "truth" measurements. The data was recorded on board and tagged with time and altitude information to allow post-flight processing.
Lidar Technology
Lidar Technology is much more advanced than today's systems for planetary navigating tasks. Preliminary tests shows that this technology is about 10 times more powerful than conventional radar-based sensors that were used in Phoenix Mars Lenders, in accuracy of velocity readings and rate of updates.
This precision range and directional velocity data are critical in navigating lunar landing vehicles to the pre-selected site and achieving autonomous, safe soft-landing.
Future of Lunar Lenders
This new technology has a potential for or aiding crew exploration vehicle rendezvous and docking, and Earth reentry landing systems. This can highly impact the design of future lunar and other planetary landing missions.
