Astrobotic Technology successfully tested the landing guidance system it will use to place a robot on the moon during a February test in the Mojave Desert aboard the Masten Aerospace Xombie, a vertical-takeoff, vertical-landing suborbital rocket.
The test of the Astrobotic Autolanding System (AAS), made possible by funding through the NASA Flight Opportunities Program, took place at the Mojave Air and Space Port in Mojave, Calif. A video of the test is available on YouTube.
The AAS uses visual navigation to provide precise real-time location updates for Astrobotic’s lunar landing craft, Griffin, and automatically avoid hazards during landing on unknown terrain. Astrobotic, a Carnegie Mellon University spinoff, will use Griffin to deliver commercial payloads to the moon. It also is developing a lunar rover that it plans to land on the moon next year to win more than $20 million from the Google Lunar XPrize.
The landing sensor uses two cameras, an inertial measurement unit (IMU), and a scanning laser.
"The pair of cameras work together like human eyes to measure distance and track motion,” said Kevin Peterson, a Ph.D. alumnus of the Robotics Institute and Astrobotic’s chief technology officer. “The scanning laser gives precise distance measurements and enables us to pick out hazards as small as a curb. The AAS landing sensor combines these sensors with an IMU – the device that enables airplane autopilots to determine direction to the ground – to build its models."
The sensors and software had previously been tested on ground vehicles, ziplines, helicopters and airplanes. But the Mojave test validated its performance while experiencing the vibration, rotation rate and plume associated with rocket flight, while the craft followed a trajectory the mimics the one that will be flown when landing on the moon. The flight test confirmed the sensor’s ability to detect hazards as small as a soccer ball. It also showed that the craft’s landing trajectory is flyable and supports hazard detection.
Astrobotic, which is working in partnership with CMU to win the Google Lunar XPrize, has qualified for Milestone Prizes offered by the XPRIZE organization, which could net the team up to $1.75 million for reaching its objectives in three categories – Landing, Mobility, and Imaging. The Milestone Prizes recognize the technological achievements and associated financial hurdles faced by teams as they prepare their lunar spacecraft.