An American-made spacecraft made a soft landing on the moon for the first time in more than half a century.
There was plenty of drama and intrigue Thursday night as Intuitive Machines attempted to land its Odysseus spacecraft in a small crater not far from the moon’s south pole. About 20 minutes after touchdown, NASA declared a success, but some questions remain about the lander’s health and its orientation. Why? Because when Odysseus called home, the signal was weak.
But after everything the spacecraft and its developer, Houston-based Intuitive Machines, have been through earlier Thursday, the fact that Odysseus managed to pull it off was nothing short of a miracle.
get lost
The landing attempt was delayed by about two hours because mission controllers had to send a hastily cobbled-together last-minute software patch to the lander while it was still in orbit around the moon. Patching a spacecraft’s software shortly before it makes its most critical maneuvers is almost the last thing an aircraft operator wants to do. But Intuitive Machines was desperate.
Earlier Thursday, the company realized its navigation lasers and cameras were inoperable. These rangefinders are critical for two functions during landing: terrain-related navigation and hazard-related navigation. Both modes help the flight computer on Odysseus pinpoint its position during descent by taking massive images and comparing them to known lunar terrain, and identify hazards below, such as boulders, in order to Find a safe landing spot.
Without these rangefinders, Odysseus would be facing the moon. Fortunately, the mission carried a large scientific payload. As part of its commercial lunar program, NASA is paying approximately $118 million to deliver six science payloads to the lunar surface.
One of the payloads happens to be the Navigation Doppler Lidar Experiment, a 15-kilogram package containing three small cameras. With this NDL payload, NASA is trying to test technology that could be used to improve navigation systems in future lunar landing attempts.
Odysseus’ only chance is that it can somehow take advantage of two of the NDL experiment’s three cameras and use one for terrain-related navigation and the other for hazard-related navigation. So the software was hastily written and shipped to the lander. This is real MacGyver stuff. But will it work?
new home
The Odysseus lander began its descent from a circular orbit 57 miles (92 kilometers) above the lunar surface, one hour and 13 minutes ahead of its planned landing time. The lander began a powered descent using its main engine powered by liquid oxygen and methane 11 minutes before touchdown on this timeline. In those final critical minutes, Odysseus’ improvised terrain-related navigation camera scanned the surface for hazards such as boulders to ensure a safe landing site.
After landing, mission controllers knew it could take a minute or two before a good signal returned from the lander, which was relaying the signal back to a large satellite dish on Earth. First for a minute, then two, and finally five, an increasingly uncomfortable silence fell in Intuitive Machines’ mission control room. there is nothing.
Finally, 10 minutes later, mission manager Tim Crain announced that the lander was sending a weak signal to Earth.
“We’re not dead yet,” said Crane, the company’s co-founder.