Odysseus passes over the near side of the moon on February 21, 2024 — the day Intuitive Machines discovered a major error that almost killed the mission.
Intuitive Machines
Intuitive Machines’ CEO says a safety switch in its lander’s navigation was accidentally left on.That oversight made the Odysseus lander’s historic moon touchdown a “spicy” nail-biter.A “space cowboy” rush to replace disabled lasers with experimental NASA tech saved the mission.
Two lucky breaks and a stroke of genius saved Intuitive Machines’ moon-landing mission on Thursday.
A serendipitous moment, a NASA experiment, and frantic, innovative software engineering rescued the company’s Odysseus lander from what could have been a catastrophic error — a switch that didn’t get flipped before launch.
That simple mistake disabled the lasers designed to guide the spacecraft to a flat, safe spot for landing, Intuitive Machines cofounder and CEO Steve Altemus told reporters on Friday.
“That was an oversight on our part,” Altemus said.
But a scrappy Hail Mary effort got Odysseus to the moon’s surface in one piece — albeit probably laying down sideways.
Intuitive Machines CEO Steve Altemus shows the world how the Odysseus lander is probably sitting on the moon right now: sideways, stuck up in the air, possibly leaning on a rock or slope, in a screengrab from NASA’s press conference.
NASA TV
It was a “spicy” landing, Altemus said. He called his team of flight operators “real space cowboys” for rapidly patching the problem.
Even to outsiders, the last-minute rush to Frankenstein together a new navigation system looked impressive.
“That’s real hardcore engineering. That’s good stuff, I have to say it. That’s the kind of thing that every engineer dreams of,” Robert Braun, who has worked on landing and descent teams for multiple NASA missions to Mars and now leads space exploration at Johns Hopkins Applied Physics Laboratory, told Business Insider.
The Houston-based company flew Odysseus, which is its Nova-C-model lander, to the moon on a $118 million NASA contract. Its success marks the first commercial moon landing ever and NASA’s first return to the lunar surface since 1972.
It almost didn’t make it, though. Here’s what happened.
The Odysseus lander’s laser safety was on
The night before the moon landing was scheduled, Intuitive Machines mission operators were troubleshooting a different, much smaller problem when they realized their navigation lasers weren’t firing.
It was lucky they discovered the issue at all.
“We would have probably been five minutes to landing before we would have realized that those lasers weren’t working if we had not had that fortuitous event,” Tim Crain, cofounder, and chief technology officer of Intuitive Machines, said in the briefing.
The fortuitous event, according to Altemus’s telling, was a weird orbit around the moon.
As mission operators were preparing for the landing sequence, they realized that the spacecraft was passing too close for comfort to the lunar south pole — the region of the landing site. They thought they might need more distance for a proper landing. No problem; all they had to do was command the spacecraft to move a bit.
To double-check the spacecraft’s location above the moon, they asked it to activate the laser rangefinders in its navigation system and ping the lunar surface.
But the lasers didn’t turn on.
The operations team was soon working “feverishly,” Altemus said.
They discovered that a safety switch — a physical switch in the hardware designed for safety during ground testing — was still on. It disabled the laser rangefinders.
“It’s like having a safety on a firearm,” Altemus explained.
It should have been switched off before launch, but now it was too late.
Altemus recalled telling Crain they would have to land without the laser rangefinders: “His face got absolutely white, because it was like a punch in the stomach that we were going to lose the mission.”
Experimental NASA tech to the rescue
Luckily, one of six NASA experiments onboard the lander was a test of a navigation system.
“That’s a remarkable, fortuitous stroke of luck,” Braun said.
Hurrying down a hallway with Altemus, to discuss the issue with more people, Crain had an idea. What if they reprogrammed the lander’s navigation system to use lasers from that experimental NASA technology as their makeshift laser rangefinders?
“It was just a brilliant piece of insight,” Altemus said.
It was risky — the NASA lasers were on the lander to test whether they worked in space at all — but it was better than nothing.
So controllers moved the spacecraft into a different orbit and pushed back the landing by about 45 minutes, buying them just enough time to upload a software patch that gave the lander its new instructions.
“In normal software development for a spacecraft, this is the kind of thing that would have taken a month,” Crain said. “Our team basically did that in an hour and a half. And it worked. It was one of the finest pieces of engineering I’ve ever had the chance to be affiliated with.”