By SpaceZE News Publisher on Wednesday, 28 February 2024
Category: Universe Today

Odysseus Is Going to Sleep After Sending Snapshots From Moon Landing

Intuitive Machines says it’s putting its Odysseus moon lander to bed for a long lunar night, with hopes of reviving it once the sun rises again near the moon’s south pole.

The Houston-based company and NASA recapped Odysseus’s six days of operation on the lunar surface, shared pictures showing its off-kilter configuration, and looked ahead to the mission’s next phase during a briefing today at Johnson Space Center in Texas.

The original plan called for the solar-powered spacecraft to be turned off when the sun fell below the lunar horizon, but Intuitive Machines CEO Steve Altemus said mission controllers would instead put the Odysseus into hibernation and try restoring contact in three weeks’ time. “We are going to leave the computers and the power system in a place where we can wake it up and do this development test objective, to actually try to ping it with an antenna and see if we can’t wake it up once it gets power again,” he told reporters.

Last week, Odysseus became the first-ever commercial spacecraft to survive a descent to the lunar surface, and the first U.S.-built spacecraft to do so since NASA’s Apollo 17 mission in 1972. NASA struck a deal to pay Intuitive Machines $118 million to deliver six science instruments to the lunar surface under the terms of its Commercial Lunar Payload Services initiative, or CLPS.

Sue Lederer, NASA’s project scientist for CLPS at Johnson Space Center, said every one of NASA’s payloads has met “some level of their objectives, and we’re very excited about that.”

NASA’s deputy associate administrator for exploration, Joel Kearns, said the space agency considered the mission to be a success despite the difficulties encountered during Odysseus’ landing. He also said the mission validated NASA’s strategy of enlisting private companies to provide robotic rides to the moon.

“It’s an exciting time to be on Day 6 of this new era in the 21st century,” Kearns said.

The new era has had more than its fair share of challenges. Tim Crain, who serves as Intuitive Machines’ chief technology officer as well as Odysseus’s IM-1 mission director, said there were at least 11 do-or-die moments along the way.

One of the most critical challenges came when the mission team discovered that the lander’s laser range-finding system couldn’t be activated for the Feb. 22 landing, due to a safety lock that wasn’t deactivated before the Feb. 15 launch.

Engineers came up with what they thought would be a last-minute fix. That involved connecting one of NASA’s payloads, an experimental laser range-finding system, to Odysseus’s internal guidance system.

However, when the Odysseus team later reconstructed the events leading up to the landing, they found out that the readings from the NASA system couldn’t be processed because they lacked a required data-verification code, Crain said. Instead, the lander had to rely on its inertial measurement unit and its optical navigation system.

That appears to explain why Odysseus’s landing was rougher than expected. “The flight dynamics guys calculate that we actually came down just short of our [intended] landing site, at a higher elevation than where our landing site was going to be,” Altemus said.

As a result, Odysseus came down to the surface at a higher downward velocity, with extra sideward velocity as well. “We hit harder, and sort of skidded,” Altemus said.

An ultra-wide-field version of an image sent back by the Odysseus moon lander during its Feb. 22 touchdown shows a landing leg breaking off and moon dirt being kicked up by engine exhaust. (Credit: Intuitive Machines)

One of the pictures released today shows Odysseus skidding to a stop, with pieces of a landing leg breaking off. “The landing gear did what it was supposed to do and protected the lander as it landed on the surface,” Altemus said.

The image also shows plumes of moon dirt spraying away from the blast of Odysseus’s engine. The lander was able to stay upright as long as its engine kept firing. “And then, as it wound down, the vehicle just gently tipped over,” Altemus said.

Crain said Odysseus’s inability to use its primary laser range-finding system was a big loss. “If we would have had the laser range-finders, we would have nailed the landing,” he said.

Instead, Odysseus is lying at a 30-degree angle, in such a way that its main solar array isn’t able to soak up as much sunlight as planned. Moreover, some of its antennas are pointing toward the ground.

The misalignment of the antennas created another problem: “Our signals were bouncing off the moon,” Crain said, and that made it harder for the team to decipher the signals that were received at ground stations around the globe.

This Feb. 27 image from Odysseus’s narrow-field-of-view camera shows the lander leaning off-kilter on the lunar surface. The prominent orange feature is a helium tank. (Credit: Intuitive Machines)

Eventually, engineers figured out how to compensate for the scrambled signals — and they mounted a full-court press to get as much data down as fast as they could. Lederer said that made a huge difference.

“Instead of ending up with a few bytes of data, which was a baseline goal for us, we’ve gotten over 50 megabytes of data,” she said. “We went from basically a cocktail straw of data coming back to a boba-tea straw of data coming back.”

The data from NASA’s payloads will help the space agency plan for follow-up robotic missions in the CLPS program — including Intuitive Machines’ IM-2 mission, which could be launched later this year. Such missions are meant to set the stage for the Artemis program’s first crewed trip to the lunar south polar region, scheduled for as early as 2026.

Odysseus also carried six private-sector payloads to the lunar surface. One of the payloads is a mini-camera system that was built by faculty and students at Embry-Riddle Aeronautical University. The system, known as EagleCam, was designed to be ejected from the lander during the descent and capture a “selfie” view of the touchdown.

Because of the anomalies surrounding Odysseus’s descent, EagleCam couldn’t be ejected for the landing. Altemus said the mission team finally reactivated and deployed EagleCam today. “It ejected about 4 meters away from the vehicle safely,” he said. “However, either in the camera or in the wi-fi signal back to the lander, something might not be working correctly.”

Altemus said the Embry-Riddle team “is working on that and wrestling with that to see if there’s anything they can do.”

Crain said it’s by no means clear whether Odysseus can be revived after the 14-day-long lunar night in the south polar region, during which temperatures could get colder than 200 degrees below zero Fahrenheit (-130 degrees Celsius). “The No. 1 limiter we face is the batteries,” he said. “Batteries are a chemical asset, and that chemistry does not respond well to deep cold. … The batteries absolutely are not tested to that level of cold. Neither is our flight computer or our radars.”

If the mission team can revive Odysseus, it would be a feat comparable to the Japanese Aerospace Exploration Agency’s revival of its SLIM moon lander last weekend.

Despite the glitches, Altemus said Odysseus, which is named after a hero in Greek mythology, should be seen as a trailblazer for the commercialization of moon exploration.

“I think it’s the tip of the iceberg. And it’s beginning, for people to realize, ‘Wow, this was an incredible success. What are the possibilities?'” he said. “I think that was the whole purpose here, to open up space exploration … so more and more people can participate. And if that’s the result we get, I’m happy for that.”

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