Imagine you are on a business trip abroad, and you are navigating through a city you are just visiting for the first time. And then, the Google Maps app fails you for some reason. What would you do? You know you are heading in the right direction, but you have no idea where exactly you have to make your next turn. The battery is slowly running out, and your scheduled meeting is closer and closer, yet further and further away…
Well, you might probably feel similar vibes in the Intuitive Machines’ control room after SpaceX’s Falcon 9 rocket sent the Odysseus moon lander to our nearest celestial body, only to realize that its navigation – the star tracker system – doesn’t work.
As reported by Ars Technica’s renowned space journalist Eric Berger, who got to visit Intuitive Machines’ control room in Houston, this was just one of 11 “crises” which almost killed the mission and drove the probability of successful moon landing to only two percent.
Claiming that Odysseus’ landing – although sideways – was nothing short of a miracle doesn’t sound any hyperbolic in this context.
In coordination with @SpaceX, our IM-1 mission launch is targeted for a multi-day launch window that opens no earlier than 12:57 a.m. Eastern Standard Time on February 14th from Launch Complex 39A at @NASA Kennedy Space Center in Florida.https://t.co/I4rIKcGaTk pic.twitter.com/qxEhicI80h
— Intuitive Machines (@Int_Machines) February 5, 2024
One of the issues that had not been reported previously was the loss of the star tracker system. The spacecraft was tumbling, the communication link was getting interrupted, and the engineers didn’t know where exactly the moon lander was.
“Hours after we got off the launch pad, we almost lost the spacecraft,” said Intuitive Machines’ CEO Stephen Altemus.
He further explained to Berger that thanks to the precise job done by Falcon 9, the team of engineers was given precious time to ultimately work out the issue, update the spacecraft, and make the crucial star tracker system operational.
Odysseus captured this image approximately 35 seconds after pitching over during its approach to the landing site. The camera is on the starboard aft-side of the lander in this phase. 2/5 (26FEB2024 0745 CST) pic.twitter.com/oUcjk3bCqW
— Intuitive Machines (@Int_Machines) February 26, 2024
One of the biggest stories related to Odysseus’ moon landing was the late switch of the navigation system for the approach and landing itself, as also previously detailed by Ars Technica.
Hours before landing, engineers realized their system for terrain and hazard awareness – another crucial system that helps pick the safe landing site and successfully touch down – was inoperable.
Luckily enough, Odysseus carried NASA’s experimental device, NDL (Navigation Doppler Lidar). Its role is very similar, and thanks to a quick patch, it helped guide the moon lander on its descent.
However, as Altemus revealed to Berger, there was a huge issue. Although the NDL was gathering data, Odysseus’ flight computer was unable to process it in real time. That meant the lander received the last accurate altitude reading when it was 15 kilometers above the Moon’s surface. From then on, the lander had to rely on its cameras and previously available data to calculate the distance from the surface as accurately as possible.
That didn’t quite work, though. Odysseus landed thinking that it was actually 100 meters above the surface, which meant the spacecraft was traveling faster than it should, both horizontally and vertically. As a result, Odysseus slid, broke one of its landing legs, and toppled on its side.
Still, though, Odysseus survived against all the odds, and ever since, the team has been doing everything humanly possible to gather and send as much useful data to the Earth as possible, laying down a healthy foundation for future commercial missions to the Moon…
Image: Intuitive Machines