By Elise Hammond and Jackie Wattles, CNN
From CNN's Jackie Wattles
The webcast just announced that the engine is "nominal" — aerospace parlance for working as expected.
The spacecraft is functioning all on its own.
The expected landing time is 6:24 p.m. ET, though there could be wiggle room.
We could learn right at that time if Odysseus made a safe touchdown, or it could take a few minutes, according to the webcast.
From CNN's Elise Hammond and Jackie Wattles
It's go time for this lunar lander.
The spacecraft is lighting its engine for an 11-minute burn. This is one of the last milestones before touchdown.
The decision to swoop in for landing comes despite the fact that the vehicle's sensors — or rangefinders — weren't working. Teams on the ground were able to troubleshoot the issue by reprogramming Odysseus to rely on an experimental NASA payload on board: The Navigation Doppler Lidar.
During this burn, the lander will slow down by about 1,800 meters per second, aiming to hit the brakes for a gentle touchdown at 6:24 p.m. ET.
From here, the spacecraft is fully autonomous and there's no communication with the vehicle until landing.
From CNN's Elise Hammond and Jackie Wattles
The Odysseus lunar lander is experiencing some issues as it gets closer to making its descent to the surface.
“It’s white-knuckle time. Their ability to land is not with the radar, but with light pulses called Lidar — and it is on the blink," NASA Administrator Bill Nelson told CNN's Jake Tapper, less than an hour away from the estimated touchdown time.
Odysseus' own system wasn't working exactly as intended.
But there are six NASA payloads on board the rover, nicknamed "Odie," and one of them is a Lidar. Nelson said scientists are trying to patch that NASA Lidar to the spacecraft and its control system.
If that doesn't work, "they would keep working the problem," he said.
"At 6:10 (p.m. ET) they’re to do a controlled descent — they would waive that descent off for one more try at about 8:30 this evening. But that would be the last chance that they would have to land," Nelson added.
Early indications were that the spacecraft was successfully using the NASA Lidar, according to the Intuitive Machines livestream.
The CEO of the company attempting to land a spacecraft on the moon Thursday said a little competition with China is not a bad thing.
More than five decades ago, the Apollo program was created because of the space race with the Soviet Union. Today, the United States is aiming to go back to the moon with a robotic explorer — and stay there. The US is aiming to land the Odysseus spacecraft near the moon’s South Pole — an area where both the US and China want to develop a moon base.
Intuitive Machines CEO Stephen Altemus told CNN on Thursday that this new kind of space race is what is going to spur progress.
"There's so much more to do on the moon — and learn on the moon — about living and working in space. If it takes geopolitical tensions to drive that to fruition, you know, that's OK," Altemus said.
“To be a company like Intuitive Machines in the forefront of landing on the moon and think of our competitor is China? That’s crazy,” he added.
In the last decade, China has sent three vehicles to the surface of the moon. The United States has not landed a robotic rover on the moon in more than 50 years.
From CNN's Jackie Wattles
Odysseus is heading for a landing site near Malapert A, an impact crater near the moon's south pole.
NASA describes it like this:
"(A) relatively flat and safe region is within the heavily cratered southern highlands on the side of the Moon visible from Earth."
The space agency said it chose this landing site for Intuitive Machines' first mission because it wanted to learn more about the lunar environment and how communications function in this area.
And there's a key reason why: NASA wants to scout the lunar south pole because the space agency believes it's the best location to set up a future astronaut base.
From CNN's Kristin Fisher and Jackie Wattles
An apparent issue with Odysseus' navigation systems will force the lander to rely on experimental technology.
"Intuitive Machines made the decision to reassign the primary navigation sensors from Odysseus....to use the sensors on NASA's Navigation Doppler Lidar," according to the webcast.
The NDL payload is an experimental technology that aimed to test out how future landers would make more precise landings on the moon. It’s designed to shoot laser beams to the ground to give exact measurements of speed and direction of flight, according to Farzin Amzajerdian, NASA's principal investigator for the instrument.
But it'll serve more than an experimental role as Odysseus heads to the moon.
"They did some checks, and they're performing very well," according to Gary Jordan, a NASA communications manager, on the livestream.
From CNN's Kristin Fisher and Jackie Wattles
Before it attempts to land on the moon, the lunar lander Odysseus, or IM-1, needs to slow its speed by about 4,026 miles per hour (about 6,500 kilometers per hour) to have a soft touchdown.
The spacecraft is on track to land around 6:24 p.m. ET Thursday near the lunar south pole.
Success is not guaranteed. Overall, more than half of all lunar landing attempts have ended in failure — tough odds for a feat humanity first pulled off nearly 60 years ago.
While technology has advanced in the past five decades, the fundamental challenges of landing on the moon remain the same. Here's what it will have to overcome:
From CNN's Jackie Wattles
Odysseus' descent won't go exactly as Intuitive Machines previously mapped out.
"This is a dynamic situation ... We'll update you later in the broadcast," said Gary Jordan, a communication manager at NASA, on the livestream.
Jordan added that an engine burn the company chose to execute overnight eliminated the need to perform a 10-second "deorbit insertion" burn, or DOI.
The spacecraft is now expected to continue decreasing its altitude over the next hour until "the breaking burn," according to the webcast.
From CNN's Jackie Wattles
Odysseus can't offer live footage of its landing attempt. The spacecraft isn't equipped with a video recorder capable of sharing its journey.
But Intuitive Machines will be sharing computer-generated graphics that are based on data delivered directly from the robotic explorer. So while it's not a live look, what appears on the livestream should be a fairly close representation of what the spacecraft is currently doing in lunar orbit.
That is, until about 10 minutes before landing.
After that, we won't be seeing live data as Odysseus begins its perilous final descent. But, if all goes well, there should be only about a 15-second delay before flight controllers confirm whether the spacecraft made it to the surface safely, according to Intuitive Machines.
The livestream is underway and you can watch at the top of this page.
This post has been updated to reflect the livestream is underway.
