Cutting corners may have led to Odysseus's fall on the moon

Did Intuitive Machines skip a pre-flight check that could have prevented the spacecraft tipping over after landing? This is really complicated, so let’s dive in. 

New moon photos from IM-1

But first, let’s take a look at the new photos from Odysseus.

It’s interesting to note that, once again, these photos are from the descent phase while Odysseus was flying low over the moon looking for a landing site. We haven’t actually seen any photos from the lander ON the moon’s surface. I discussed yesterday that I think these photos are coming so slowly, due to bandwidth issues.

But also it is interesting if you look at the language that Intuitive Machines used in their latest post on former Twitter.

The fact that Company is capitalized, and the use of the word “furtherance” makes me think the lawyers are now writing or severely editing the releases, perhaps because Intuitive Machines’ stock price has not been doing well after news about both the lander being sideways and the communications issues. 

As this point I have to wonder if they have the lunar surface photos and are hesitant to release them. They might look terrible because the lander fell over.

But we did get the good news that Odysseus might have 10-20 extra hours of communication. Yesterday Intuitive Machines told us they thought they would lose communication ability this morning, so that means more time to download photos and data. Hopefully we’ll get more photos at some point soon.

What went wrong with the laser range finder system?

Moving on, let’s talk about what exactly went wrong with the laser range finder, the pre-flight checks, and some larger context.

An excellent Reuters article by reporters Steve Gorman and Joey Roulette reveals that Intuitive Machines’ decision to skip a test fire of the laser system is what led to the failure of the laser range finders, and last minute switch to NASA’s LIDAR. And it’s possible—though not definite—that’s what led to the lander’s sideways tumble.

I want to dive into this because it’s complicated. Let’s start with what exactly happened with the laser rangefinders. 

The laser range finders aboard the Nova-C lander are crucial to landing successfully. This system is designed to measure the spacecraft’s altitude from the moon’s surface and the forward speed it’s traveling at. So, a pretty important system when you’re trying to soft land a spacecraft on the moon.

But it was actually really lucky they found out the laser range finder system wasn’t working when they did. 

According to Steve Altemus, the CEO and co-founder of Intuitive Machines, way before descent, when the team realized the spacecraft was in an elliptical orbit and not circular, they decided to switch on the laser range finders to figure out how close to the surface they actually were. They wanted a better measurement.

But the lasers didn’t fire. 

Thankfully, NASA had a LIDAR navigation system aboard the spacecraft that was just there to be tested on the lunar surface. 

But here’s the thing — the fact that they tried to fire the range finders early was fortuitous because if they hadn’t, the issue would have become clear during the descent phase, and there would have been no time to do anything. The spacecraft would have crashed.

The team had to rewrite the navigation application software to use NASA’s system for navigation and guidance and upload it to the vehicle. When they did that, it actually stopped Odysseus’s navigation, guidance and control (which is why they did it during that extra orbit of the moon that delayed the landing time on Thursday). But they were able to reboot the system and the patch worked. 

But that leads to the question of why the laser range finder system wasn’t working. I’ll let Steve Altemus, CEO and co-founder of Intuitive Machines, explain why, in his own words. This is from the press conference on Friday.

”And we saw that that laser didn't fire, and what we found was that there was a safety enabled switch—because it's not an eye safe laser. That safety enabled switch, which is in the box and was not disabled. It's like having a safety on a firearm. It's for ground processing, and that was an oversight on our part. And so those laser range finders could not be turned on, and we couldn't manipulate that disabled switch with the software.”

The bottom line is that this was human error, someone forgot to disable the safety switches before launch. 

Skipping pre-flight checks led to this oversight

Human error certainly happens in every area, including building spacecraft. But Mike Hansen, the head of navigation systems at Intuitive Machines, told Joey Roulette and Steve Gorman for this Reuters article that they missed the safety switch issue because they opted to skip a pre-flight check that would have test-fired the laser range finder system. If they’d done that, they would have found the problem and corrected it.

And the reason? To save both time and money. They took a risk, and probably underestimated how hard spaceflight actually is, and they lost. Intuitive Machines has two lunar landings left, and I’m guessing they won’t skip those checks next time.

The question is whether the loss of the laser range finder system led to Odysseus tipping over. This is a complicated question, and right now Intuitive Machines doesn’t have an answer, according to the Reuters article. Mike Hansen said it could very well have, but it also might not have made a difference.

In terms of what happened to the lander specifically, it came down faster than expected (at 6 meters per second, or 13.5 miles per hour, instead of 1 meter per second, or 2 miles per hour), with a horizontal velocity of zero. Instead the horizontal, or lateral velocity was 1 meter per second or two miles per hour.

What they think happened is that the lander did come down vertically but got a foot caught on a rock or in a crevice. It’s unclear whether the fall fractured part of the landing gear, but they do think Odysseus is elevated and not flat on the lunar surface, maybe laying on a rock, based on the telemetry. 

The NASA system, called Navigation Doppler Lidar for Precise Velocity and Range Sensing, uses light instead of lasers to measure speed, direction, and altitude. It operates on the same principles as radar, with high accuracy, and is designed to help spacecraft soft land on the moon. And it does seem as though Odysseus did have its Terrain Relative Navigation camera, given this image they released from the camera, and the Hazard Detection and Avoidance System were intact. So it’s hard to say whether any deficiencies of the NASA system (which I’m not trying to trash talk NASA’s LIDAR, it just wasn’t designed for this specific spacecraft) contributed to the fall.

Is this just a problem with private spaceflight?

I’ve seen a lot of comments saying that skipping preflight checks to save time and money, as well as human error, is a problem with private spaceflight, and I absolutely agree that private spaceflight definitely has issues. But also, NASA absolutely takes has problems with human error. I point at the loss of Apollo 1, Challenger, and Columbia. 

More recently, NASA chose not to do a complete a Wet Dress Rehearsal (which fully loads the launch vehicle with propellant and takes the launch countdown to T-9 seconds) on Artemis I because of schedule and money. They decided not to fully load propellant into the ICPS, or second stage of SLS, during the modified WDR and the launch was a bit of a mess as a result.

This is a tradeoff that gets made with something as complex as spaceflight. I’m not saying it’s a good thing, and I’m not defending Intuitive Machines here (this was a pretty bad screw up that could have been devastating if NASA hadn’t had the LIDAR system aboard), but I think the blanket statement that private spaceflight is worse than NASA specifically because of human error and judgment calls on time and money is not accurate. 

Spaceflight is hard, and this was a really dumb mistake, but hopefully next time Intuitive Machines will learn from this experience and do better. 

I’ll be back with more news as it comes in!