During the second moonwalk of the Apollo 14 mission, Alan Shepard and Edgar Mitchell were hoping to walk to the 300 meter (1,000 feet) wide Cone Crater on the moon, not far from their landing site. However, the two astronauts were not able to find the crater’s rim amid the rolling, repetitive terrain. Later analysis using pictures the two astronauts took determined they had come within 65 feet of the crater. Due to lack of proper navigation system they came across this situation.
In current scenario we’re using GPS more or less everywhere.
A spacecraft is able to figure out its location with precision, due to the fact that the stars are fixed.
On Earth, things are pretty simple and we rely mostly on GPS to tell us where we are.
Due to the fixed stars — satellites in geosynchronous orbits — which are constantly emitting signals, our devices can detect those signals and locate themselves.
Theoretically, there’s nothing stopping GPS signals from being measured out on the moon. Actually, NASA has already done it with the MMS mission a couple of years ago.
Jason Mitchell, the chief technologist for Goddard’s Mission Engineering and Systems Analysis Division, says “We’re using infrastructure that was built for surface navigation on Earth for applications beyond Earth. In fact, with MMS, we’re already nearly half way to the Moon.”
Using phones out there is not an option, of course, because our devices are calibrated for sampling and calculating only signals from satellites known to be in orbit, on a certain range of distances.
On the Moon, the time for the signal to reach us it would take perhaps a full second and a half. Maybe it doesn’t sound much, but it significantly affects how the receiving and processing systems have to be built.
Therefore, the team at NASA Goddard has been working on that with new navigation computer which uses a special high-gain antenna, along with a very precise clock. Technology in the field of miniaturization will prove to be of utmost importance if the GPS system for the Moon has to be developed.
NASA hopes to finish the lunar NavCube hardware by the end of the year, and then test it as soon as possible, through a flight on the Moon.