Image Credit: NASA Photo / Tom Tschida
SpaceX is not the only organization making significant strides in autonomous landing technology. NASA.gov as a has a good writeup on the results of tests conducted last December using Masten’s Zombie low altitude rocket to simulate Mars landings.
The key difference here is that by using the imaging technology of the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT) on board Masten’s XA-0.1B “Xombie” vertical-launch, vertical-landing reusable rocket, the vehicle is able to navigate to a selected spot using comparative images of the chosen terrain rather than a GPS system which is presently only serving the home planet. And while both Mars and the Moon may one day have their own GPS equivalents, there are many other interesting destinations in the solar system which likely never will. This sort of technology makes it possible to land safely on many of them.
Its tough however, to make a safe landing if you’re running on fumes, which is where the other element being tested comes into play. It is the Guidance for Fuel-Optimal Large Diverts (G-FOLD) algorithm, which combined with ADAPT, selects the most fuel efficient solution for landing when a divert is required. The complete story is here.