In a test yesterday, NASA demonstrated that it can land an unmanned spacecraft on a rugged planetary surface in the pitch dark.
The free-flight test was the first of its kind for NASA's Autonomous Landing Hazard Avoidance Technology, or ALHAT.
During testing, Morpheus -- an unmanned spacecraft capable of carrying 1,100 pounds (499 kg) of cargo -- powered its way up to more than 800 feet (244 m) into the dark Florida sky at NASA's Kennedy Space Center using solely ALHAT's Hazard Detection System for guidance.
The Hazard Detection System, assisted by three light detection and ranging (lidar) sensors, located obstacles -- such as rocks and craters -- and safely landed on the lunar-like hazard field a quarter mile away from the NASA Center.
"The team has been striving for almost eight years to reach this point of testing the ALHAT system in a relevant space-flight-like environment on Morpheus," said Eric Roback, ALHAT flash lidar lead engineer.
During testing, the Hazard Detection System pointed its sensor at the hazard field and made a mosaic of flash lidar three dimensional range images encompassing the hazard field.
"The flash lidar performed very well, and we could clearly identify rocks as small as one foot (0.3 m) in size from the largest range that Morpheus could give us, which was approximately a quarter mile," (402 m) Roback said. "With this sensor we could even find the safest landing site in a pitch black crater."
The Hazard Detection System then had to stitch the flash lidar images together to create a three dimensional map of the landing site, analyze the map and select the best landing sites. Shortly after, the Doppler lidar measured the vehicle's altitude and velocity to land precisely on the surface. The high-altitude laser altimeter provided data enabling the vehicle to land at the chosen landing site.
"Once this technology goes into service, the days of having to land 20 or 30 miles (32 to 48 km) from where you really want to land for fear of the hazardous craters and rocks will be over," Roback said. "Then we can land near the truly interesting science and near the critical resources that will be needed for eventual colonization, and we can do it over and over again safely."
The ALHAT Hazard Detection System brings together expertise from three different NASA Centers. NASA Langley Research Center in Hampton, Virginia, created the lidar sensors. NASA's Jet Propulsion Laboratory in Pasadena, California, developed the pointing and real-time image processing technology, and NASA's Johnson Space Center in Houston developed the guidance, navigation and control technology.
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.
For more information about ALHAT, visit: http://alhat.jpl.nasa.gov/
For more information about Morpheus, visit: http://morpheuslander.jsc.nasa.gov/