One day after its historic landing, the first private spacecraft on the moon is in good condition but has toppled over, the company that built it reported on Friday.
The spacecraft, named Odysseus, set down in the moon’s south pole region on Thursday evening, the first U.S. vehicle to land softly on the moon since Apollo 17 in 1972.
“The vehicle is stable near or at our intended landing site,” Steve Altemus, the chief executive of Intuitive Machines said during a NASA news conference on Friday. “We do have communications with the lander.”
He added, “That’s phenomenal to begin with.”
But the landing did not go perfectly. Because the spacecraft fell over, its antennas are not pointed directly at Earth, limiting the amount of information that can go back and forth.
Odysseus has not sent back any photographs since landing, although Mr. Altemus did show one that was taken while the spacecraft was descending to the surface. “You see how shadowed and undulating the terrain is,” he said.
Engineers at Intuitive Machines are still trying to extract more information from the spacecraft.
Mr. Altemus and Tim Crain, the chief technology officer, also described unforeseen glitches that nearly doomed the mission. The landing was salvaged through serendipity and frantic work, they said.
When Odysseus arrived at the moon on Wednesday, it was supposed to enter a circular orbit about 62 miles above the surface. But because of inaccuracies in its trajectory, the spacecraft ended up in an elliptical orbit. An added engine burn placed Odysseus in a better orbit.
To check how close the spacecraft was getting to the moon’s surface, flight controllers turned on the laser range finders, instruments that could measure the spacecraft’s altitude during landing by firing laser pulses at the moon’s surface.
But when controllers checked the data the next morning — just hours before the planned landing on Thursday — they discovered that one laser had not fired. It was then discovered that the safety switches on the two range finder lasers were still enabled when Odysseus went to space.
There was no way to flip the switches — they could not be bypassed through software — now that the spacecraft was more than 200,000 miles away.
“I can laugh about it now,” Mr. Altemus said at the news conference.
“Tim was on console as the mission director, and I said, ‘Tim, We’re going to have to land without laser range finders,’” he said. “And his face got absolutely white, because it was like a punch in the stomach, that we were going to lose the mission.”
They were brainstorming possible workarounds when Dr. Crain realized that Odysseus actually had a handy backup onboard.
It was also carrying an experimental instrument called the Navigation Doppler Lidar, which NASA wanted to test — essentially a more sophisticated instrument with three laser beams that measure not just altitude but the velocity of the spacecraft during its descent.
That instrument could provide the missing readings.
“It sounds easy in retrospect,” Dr. Crain said. All the engineers had to do was patch the spacecraft’s software in order for the NASA instrument to provide its readings to the guidance, navigation and control computer.
“In normal software development for a spacecraft, this is the kind of thing that would have taken a month,” Dr. Crain said. “Our team basically did that in an hour and a half.”
That Odysseus arrived at the moon in the wrong orbit turned out to be lucky. Without the need to check the orbit, the laser altimeter would not have been turned on until an hour before landing. At that point, it would have been too late to find a solution to the locked range finders, and Odysseus almost certainly would have crashed.
“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,” Dr. Crain said. “So serendipity is absolutely the right word.”
There was still one more problem.
Installing the software changes in Odysseus required rebooting the onboard computer. An attempt to do that in a sophisticated test simulation indicated that the spacecraft would drift off course. So controllers had to figure out a way to reboot the computer without dooming the spacecraft.
“We had to work feverishly,” Mr. Altemus said. “That was the one that had us all biting our nails just a little bit.”
The extra orbit added two hours for them to finish.
The jury-rigged navigation software worked.
Despite it all, something did not work quite right as the spacecraft touched down. The lander was descending faster than expected and still moving sideways at two miles per hour, when the motion should have been perfectly vertical.
One of the six landing legs might have snagged the surface, toppling the spacecraft. “We might have fractured that landing gear and tipped over gently,” Mr. Altemus said.
A Japanese spacecraft also tipped over while landing on the moon in January. That spacecraft, known as Smart Lander for Investigating Moon, or SLIM, was also still in working condition after its tumble.
The engineers at Intuitive Machines are still working to speed up communications with Odysseus and determine what scientific tasks can still be performed. That includes a small camera system built by students at Embry-Riddle Aeronautical University in Daytona Beach, Fla., that was supposed to eject when Odysseus was about 100 feet above the ground and capture pictures of the landing.
There was not enough time to include the deployment of the camera in the patched landing software, so it remains attached to Odysseus. But Mr. Altemus said Odysseus might still be able to eject the camera, which could then take some photographs of the area.
The Odysseus mission is likely to end by next weekend. “We know at this landing site the sun will move beyond our solar arrays, in any configuration, in approximately nine days,” Dr. Crain said.
The spacecraft is not designed to survive the frigid temperatures of the two-week-long lunar night, although perhaps Odysseus will revive when the sun rises again.
“We’ll just see if our electronics made it through,” Dr. Crain said. “We’ll take a look. We’ll take a listen.”
Source: nytimes.com