Friday, February 23, 2024

The IM-1 Story You Haven't Heard

Everyone has heard that Intuitive Machines Odysseus lunar lander and IM-1 mission has successfully landed on the moon.  Unless you've been digging, you probably haven't heard that the mission went through a phase of being doomed, then a MacGyver-like last minute fix that restored the mission and achieved the landing.  Eric Berger at Ars Technica has the story, and as I've often done, I'll pull a couple of paragraphs and recommend you Read The Whole Thing.

There was high drama and plenty of intrigue on Thursday evening as Intuitive Machines attempted to land its Odysseus spacecraft in a small crater not all that far from the south pole of the Moon. About 20 minutes after touchdown, NASA declared success, but some questions remained about the health of the lander and its orientation. Why? Because while Odysseus was phoning home, its signal was weak.

But after what the spacecraft and its developer, Houston-based Intuitive Machines, went through earlier on Thursday, it was a miracle that Odysseus made it at all.

The landing attempt was delayed by about two hours after mission controllers had to send a hastily cobbled together, last-minute software patch up to the lander while it was still in orbit around the Moon. Patching your spacecraft's software shortly before it makes its most critical move is just about the last thing a vehicle operator wants to do. But Intuitive Machines was desperate.

Desperate and with no alternatives designed for just this sort of situation.

Earlier on Thursday, the company realized that its navigation lasers and cameras were not operational.  As an autonomous probe, Odysseus was designed by Intuitive Machines to use cameras onboard for two purposes.  First, to compare terrain images to a stored database, to help the lander decide where it is and second to look for smaller things like boulders or unknown things to avoid when it came time to land.  The lasers were used as altimeters.  The combination provided what IM refers to as terrain-relative and hazard-relative navigation.

Without those sensors, Odysseus was blind.  Not just blind, but hopelessly blind without a seeing eye dog or cane.

Without these rangefinders, Odysseus was going to faceplant into the Moon. Fortunately, this mission carried a bunch of science payloads. As part of its commercial lunar program, NASA is paying about $118 million for the delivery of six scientific payloads to the lunar surface.

One of these payloads just happened to be the Navigation Doppler Lidar experiment, a 15-kg package that contains three small cameras. With this NDL payload, NASA sought to test out technologies that might be used to improve navigation systems in future landing attempts on the Moon.

The only chance Odysseus had was if it could somehow tap into two of the NDL experiment's three cameras and use one for terrain-relative navigation and the other for hazard-relative navigation. So, some software was hastily written and shipped up to the lander. This was some true MacGyver stuff. But would it work?

You know the answer to that big question now, but watching the landing was a bit different.  Earlier in the day, I'd watched some videos from IM and knew that they expected the software to take 15 seconds to radio back that it had landed, and Tim Crain - mission director and co-founder of the company - had said, "those are the longest 15 seconds of your life."  It was more like 15 minutes.  Alright, 10 minutes that felt like 15 when Crain said the lander was sending a faint signal back to Earth, adding, “we’re not dead yet.”

This morning, IM updated the mission webpage at 8:18 CST, saying:

Odysseus is alive and well. Flight controllers are communicating and commanding the vehicle to download science data. The lander has good telemetry and solar charging. We continue to learn more about the vehicle’s specific information (Lat/Lon), overall health, and attitude (orientation).

Odysseus took this selfie while passing over the near side of the Moon, after lunar orbit insertion on February 21.  Image credit: Intuitive Machines 

In this morning's update to the mission web page, they also added, “Intuitive Machines CEO Steve Altemus will participate in a press conference later today to discuss this historic moment.” So far, that page hasn't been updated but I expect there will be a press conference as described. Note that it said NASA paid $118 million to send six experiments to the moon as part of its CLPS program (Commercial Lunar Payload Services).  NASA also paid Astrobotics for a ride to the moon on their Peregrine lander that didn't make it also as a part of CLPS. 

Final words to Eric Berger:

So why is NASA supporting such risky ventures?

The space agency believes that private companies will eventually get the hang of flying vehicles to the Moon. And once the service becomes more routine, it will cost NASA a fraction of the price it would pay for traditionally developed lunar services. In essence, then, NASA is taking some short-term risks for some long-term gains. It looks like one of those risks paid off Thursday.


  1. I didn't hear that they had lost the landing cameras/altimeter until they mentioned that they had to patch into one of the payloiad's' data streams if possible.

    If you can, all you need is to get the data from the experiment's camera(s) and make sure it converted to a format that the flight computer can understand. It's not insurmountable, you may have to do some bit-diddling, but it's straightforward.
    However, it takes time, and you really don't have much opportunity to test it. THAT'S the hair-on-fire element that causes premature gray hair!

    I've done crap like this before, but not in real-time (and real SHORT time!). It's pressure to the Nth degree!!

    Kudos, guys/gals. I'm awfully glad *I* wasn't in the hot seat!!

    1. I figured there was probably a couple of video formats that were most popular in their worlds and it shouldn't be really hard to convert them, and maybe there are existing pieces of software to convert formats. There's a few assumptions embedded in that.

      The wild card is whether or not this was something they thought about and had as backup plan for last resort situations. Either run something that isn't optimum or the mission's over.

      The news conference went off around the time I finished posting this, Video here.

    2. So. The little bugger tripped and fell over. Well, they're getting science, good data, and downloading all the data procured so far.

      Small wonder the signal received here on Earth was way, way weaker than they were expecting!

      Still and all, it's a win!

  2. After listening to the public conference from IM on how things happened and all the interaction between the teams and some planning for sharing nav and other data between the guidance/nav computer and the onboard experiments, they had actually planned ahead of time for some "what if" problems that may have cropped up.
    Contingency planning, y'all. It's not just for war...