Inside a small control room, during the middle of the day on Thursday local time in Texas, about a dozen white-knuckled engineers at a space startup named Intuitive Machines started to get worried. Their spacecraft, a lander named Athena, was beginning its final descent down to the lunar surface.
A little more than a year had passed since the company’s first attempt to land on the Moon with a similarly built vehicle, Odysseus. Due to problems with that spacecraft’s laser rangefinder, it skidded into the Moon’s surface and toppled over.
So engineers at Intuitive Machines had checked, and re-checked the laser-based altimeters on Athena. 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.
Probably lying on its side
Beyond that, Crain and the rest of the company, including its chief executive Steve Altemus, could not precisely say what happened. After Athena landed, the engineers in mission control could talk to the spacecraft, and they were able to generate some power from its solar arrays. But precisely where it was, or how it lay on the ground, they could not say a few hours later.
Based on a reading from an inertial measurement unit inside the vehicle, most likely Athena is lying on its side. This is the same fate Odysseus met last year, when it skidded into the Moon, broke a leg, and toppled over.
“I would like to get a picture,” Altemus said. “I would like to get more data before we can determine the orientation.”
NASA, and several other companies, had packed a lot of interesting payloads onto the lander. The mission was designed to last, nominally, for a couple of weeks while solar energy was available. However, due to its present orientation, Athena is not receiving full power. This will limit activities in the coming days.
It does seem that Athena landed relatively near its target, the Mons Mouton area of the Moon, further south than any lander has set down on the Moon. This flat-topped mountain, which towers above the surrounding area, is about 100 miles from the lunar south pole.
One key question is whether the spacecraft’s primary mission, the PRIME-1 experiment with an ice drill to sample any ice that lies below the surface, will be able to function. NASA officials were non-committal during a news conference when asked Thursday if this drill could still be deployed.
Successes and challenges
The space agency’s chief of science, Nicola Fox, sought to put a positive spin on the sideways landing of the Intuitive Machines spacecraft. She noted that there are, at present, two US spacecraft landed on the Moon and active. There is Athena, and the Firefly Aerospace-built Blue Ghost lander that touched down four days ago.
“This is a community,” Fox said. “We all share in each other’s successes. And we all empathize with each other’s challenges.”
NASA deserves credit for funding risky missions like that undertaken by Intuitive Machines and Firefly. Heretofore only government-led missions from the United States, Soviet Union, China, and India have successfully made a soft landing on the Moon. But it still must be difficult to accept that a second Intuitive Machines lander was felled by a problem with the same instrument, its altimeter.
Look, this stuff is really hard. And it’s even more difficult for a publicly traded company like Intuitive Machines. The company’s stock opened trading at $13.65 on Thursday, and closed at $11.26. In after hours trading, it sunk to about $8.