Almost half a century after Eugene Cernan became the last human to leave his footprints on lunar soil in December 1972, NASA intends to go back to the Moon with a bang in 2020. And when it does so, the agency proposes to have a global positioning system (GPS)-like system up and running, ensuring that astronauts never get lost during the hectic explorations likely to take place. (See: NASA awards $745-million contract to manufacture spacesuits for astronauts)
In fact, getting lost or not reaching one's intended destination on the Moon is not a problem only for the future. It has already happened. The man in charge of developing the new system, Ohio State University researcher Dr Ron Li, has described incidents during past lunar missions when astronauts were travelling to a target site such as a crater, and got within a few yards of it, but couldn't see the crater because of difficult terrain.
"They were so close, but they had to turn back for safety's sake," he said. Hopefully, with the new system, that will no longer be the case.
The Moon doesn't have satellites to send GPS signals. So NASA has awarded Li $1.2 million over the next three years to develop a navigation system that will feel a lot like GPS to the astronauts that use it, but will rely on signals from a set of sensors including lunar beacons, stereo cameras, and orbital imaging sensors.
A group of The Ohio State University (OSU) researchers are working with NASA Glenn Research Center, Massachusetts Institute of Technology and the University of California, Berkeley, to develop the system, which they have named the entire system the Lunar Astronaut Spatial Orientation and Information System (LASOIS).
Li described the project in a poster session Monday at the NLSI Lunar Science Conference, held at NASA Ames Research Center in Moffett Field, California.
The new grant grew out of Li's ongoing development of software for the Mars rovers Spirit and Opportunity. Researchers have learned a lot about navigation from exploring the red planet. New technology - sensors, inertial navigation systems, cameras, computer processors, and image processors - will make the next trip to the Moon easier for astronauts.
People are used to having certain visual cues to judge distances, such as the size of a building or another car on the horizon, Li explained. But the moon has no such cues. Getting lost, or misjudging a distant object's size and location would be easy, and extremely dangerous.
Keeping astronauts safe will be a top priority for Li's team, which includes experts in psychology and human-computer interaction as well as engineering.
"We will help with navigation, but also with astronauts' health as well," Li said. "We want them to avoid the stress of getting lost, or getting frustrated with the equipment. Lunar navigation isn't just a technology problem, it's also biomedical."
This artist's rendering shows an astronaut's-eye view of the lunar navigation system that Ohio State University researchers and their colleagues are developing. Courtesy of Kevin Gecsi, Ohio State University.
The system will work by combining images taken by satellites in orbit around the moon with images taken by the ground crew on the lunar surface. The lunar vehicles used by astronauts on the moon, along with the astronauts' suits will have tracking and motion sensors to help triangulate their exact location. A computer network will make use of lunar beacons, orbital imaging sensors, and stereo cameras to make up the rest of the system.
Li, who leads Ohio State's Mapping and Geographic Information Systems Laboratory, will work with Kaichang Di, a research scientist, and Alper Yilmaz, an assistant professor, both of civil and environmental engineering and geodetic science. Yilmaz works in the university's Photogrammetric Computer Vision Laboratory.
LASOIS partners at NASA Glenn Research Centre will convert a pre-existing communications beacon to do double-duty for communication and navigation. Massachusetts Institute of Technology researchers will design the touch-pad that astronauts will wear - possibly on the arm of their space suits, Li said - to view their location and search for new destinations.
University of California, Berkeley, researchers will work out the visual cues that astronauts will need to find their way, and study the kinds of psychological stress they will experience.
According to Li's plan, the team will create a prototype navigation system, then travel to the Mojave Desert to test and refine it. The third year would possibly be spent testing the system on NASA astronauts.
NASA would then have several years to incorporate the navigation system into its other lunar technologies before 2020.