When the lander got down within about 30 km of the lunar surface, they tested the rangefinders again. Worryingly, there was some noise in the readings as the laser bounced off the Moon. However, the engineers had reason to believe that, maybe, the readings would improve as the spacecraft got nearer to the surface.
"Our hope was that the signal to noise would improve as we got closer to the Moon," said Tim Crain, chief technology officer for Intuitive Machines, speaking to reporters afterward. It didn't. The noise remained. And so, to some extent, Athena went down to the Moon blind. The spacecraft's propulsion system, based on liquid oxygen and methane, and designed in-house, worked beautifully. But in the final moments, the spacecraft did not quite know where it was relative to the surface.
fireflyspace.com
