SpaceX F9 - IM-1 Nova-C Lander - LC-39A - Includes Post Launch Discussion

[ecarfan]

The CEO of IM invited Eric Berger into IM-1 Mission Control, clearly to try to pitch him that the mission was an “absolute success”. And after the visit, Berger agrees with him. He also learned some heretofore unrevealed information.

It turns out that Odysseus landed on the Moon without any altimetry data​

Altemus [the CEO] said Tuesday that the flight computer onboard Odysseus was unable to process data from the NASA payload [the hastily patched in alternate nav system] in real time. Therefore, the last accurate altitude reading the lander received came when it was 15 kilometers above the lunar surface—and still more than 12 minutes from touchdown. That left the spacecraft, which was flying autonomously, to rely on its optical navigation cameras. By comparing imagery data frame by frame, the flight computer could determine how fast it was moving relative to the lunar surface. Knowing its initial velocity and altitude prior to initiating powered descent and using data from the inertial measurement unit (IMU) on board Odysseus, it could get a rough idea of altitude. But that only went so far.
"So we're coming down to our landing site with no altimeter," Altemus said.

Yikes. That’s incredible. No wonder the landing did not go well.

Unfortunately, as it neared the lunar surface, the lander believed it was about 100 meters higher relative to the Moon than it actually was. So instead of touching down with a vertical velocity of just 1 meter per second and no lateral movement, Odysseus was coming down three times faster and with a lateral speed of 2 meters per second.
"That little geometry made us hit a little harder than we wanted to," he said.
But all was not lost. Based upon data downloaded from the spacecraft and imagery from NASA's Lunar Reconnaissance Orbiter, which flew over the landing site, Intuitive Machines has determined that the lander came down to the surface and likely skidded. This force caused one of its six landing legs to snap. Then, for a couple of seconds, the lander stood upright before toppling over due to the failed leg.

And supposedly a photo is coming tomorrow taken by the lander at the moment of touchdown, just after one of the legs broke but it was still upright.

 

[ecarfan]

Berger rates the mission as a success because:

…NASA is thrilled with Intuitive Machines' performance. The aerospace industry at large understands what this company was up against and is celebrating its success. Most of the customers flying on Odysseus are getting the data they paid for. The reality is that Intuitive Machines is a private company with about 250 people working on this lunar lander program. That's a small fraction of the resources that national space programs typically devote to these initiatives, and with all the data it has gathered, Intuitive Machines and its customers can be pretty confident that the company will stick the landing next time. And there will be a next time, as the commercial lunar landers built by private companies in the United States cost about $100 million instead of the half-billion dollars the government would have spent on a specialized, one-time mission to the Moon.

I am looking forward to the next IM mission and have some confidence that it will go much more smoothly.

 

[scaesare]

I agree that the team pulled a bit of a rabbit out of the hat and made what could have been a total loss in to a reasonable success... good for them. And glad they are positive and NASA is too...

Getting that pic will be cool to see...

 

[JB47394]

I am looking forward to the next IM mission and have some confidence that it will go much more smoothly.

You can be sure that the laser rangefinder safety will be off before launch.

 

[Grendal]

 

[HVM]

https://twitter.com/x/status/1762919217089720716

 

[ecarfan]

Eric Berger:

Intuitive Machines has determined that the lander came down to the surface and likely skidded. This force caused one of its six landing legs to snap. Then, for a couple of seconds, the lander stood upright before toppling over due to the failed leg.

I’m guessing that the broken landing leg was on the downhill side, causing the tip over. With 6 legs, it seems like if the lander had touched down on level ground and one leg broke it would remain upright.

 

[JB47394]

This image illustrates Odysseus' landing strut performing its primary task, absorbing first contact with the lunar surface to preserve mission integrity. Meanwhile, the lander's liquid methane and liquid oxygen engine is still throttling, which provided stability. The Company believes the two insights from this image enabled Odysseus to gently lean into the lunar surface, preserving the ability to return scientific data.

My head is getting dizzy from the spin. Thank goodness Eric explained what happened in English.

I’m guessing that the broken landing leg was on the downhill side, causing the tip over. With 6 legs, it seems like if the lander had touched down on level ground and one leg broke it would remain upright.

Downhill side?

 

[ICUDoc]

" ..landing strut performing its primary task, absorbing first contact with the lunar surface to preserve mission integrity. "
What an extraordinary use of language.

 

[ecarfan]

Downhill side?

Well, we’ve been told the lander touched down on a 12 degree slope. If the uphill leg had broken it seems like the lander may well have remained upright?

Because the vehicle thought it was at about 100m when it impacted the surface, perhaps it was not fully vertical, so the leg that broke was the first one to touch the surface.

I’m just speculating of course.

 

[ecarfan]

" ..landing strut performing its primary task, absorbing first contact with the lunar surface to preserve mission integrity. "

I did not think there were shock absorbers in the legs.

Seems to me the primary task of the legs is to keep the lander vertical when it is on the surface of the Moon. To me the broken leg actually failed at its primary task.

But in the world of IM speak, the legs worked correctly.

 

[ecarfan]

Eric Berger’s description of the latest info from IM: That moment when you land on the Moon, break a leg, and are about to topple over

As it impacted and skidded, the spacecraft's main engine was still firing. Then, just as the spacecraft touched down more firmly, there was a spike in the engine's combustion chamber. This is consistent with the bell-shaped engine nozzle coming into contact with the lunar surface.
It is perhaps worth pausing a moment here to consider that this spacecraft, launched a week earlier, had just made an autonomous landing without knowing precisely where it was. But now it found itself on the Moon. Upon impact, one or more of the landing legs snapped as it came down hard. Then, at that very moment, with the engine still burning, an onboard camera snapped an image of the scene. Intuitive Machines published this photo on Wednesday. It's spectacular.
"We sat upright, with the engine firing for a period of time," Altemus said. "Then as it wound down, the vehicle just gently tipped over."

And IM released this photo. It’s not clear to me which way the surface is sloping or whether the broken landing leg is uphill or downhill or to one side. And Berger says it is possible more than one leg broke.

 

[JB47394]

Well, we’ve been told the lander touched down on a 12 degree slope. If the uphill leg had broken it seems like the lander may well have remained upright?

If you land upright on a slope, the uphill legs will contact first. Surely they should break first. Assuming that they snap and don't just compress, you now have support on the downslope side, but none on the upslope side. Worse, assume that you're skidding in the direction of the snapped legs. It'll fall over to the upslope side.

Remember too that the lander was initially believed to have fallen over onto a rock. The uphill slope would fill that role.

Separately, we talked about the likelihood of a skid based on that bright patch in the LRO images. I guess that much is confirmed.

 

[ecarfan]

Agreed, but the lander thought it was 100M high when it impacted the surface; perhaps it had not fully pitched over.

Again, my speculation.

 

[HVM]

[Symbol of Metre is lowercase m, muttering in SI]

 

[ecarfan]

NYT reports:

During a news conference on Wednesday afternoon, Intuitive Machines, the Houston-based company that built Odysseus, said the spacecraft continued to operate, but that it would be put into a planned shutdown within a few hours.
Despite everything that did not work quite right, Steve Altemus, the chief executive of Intuitive Machines, called the mission “an unqualified success.”

In the real world this mission is definitely a “qualified success”. Many things went right. Many things went wrong. Next time they will do better.

 

[scaesare]

Agreed, but the lander thought it was 100M high when it impacted the surface; perhaps it had not fully pitched over.

Again, my speculation.

It was also travelling laterally faster than expected (~3mph), so I suspect that as soon as it touched, all the load transferred to the "leading" leg as it dug in....

 

[scaesare]

So they said:

Meanwhile, the lander's liquid methane and liquid oxygen engine is still throttling, which provided stability.

I wonder if that's just because the engine was still firing because it didn't have altimeter data, or if they are implying the lander could tell it was starting to pitch over, and was deliberately attempting to thrust for stability?

The latter scenario makes me think of the Falcon 9 that knew it was going over due to a buckled leg and tried valiantly to keep itself up with it's cold gas thruster lol:

 

[Grendal]

So they said:



I wonder if that's just because the engine was still firing because it didn't have altimeter data, or if they are implying the lander could tell it was starting to pitch over, and was deliberately attempting to thrust for stability?

The latter scenario makes me think of the Falcon 9 that knew it was going over due to a buckled leg and tried valiantly to keep itself up with it's cold gas thruster lol:

Nice. A great example of what the lander was probably trying to do. Luckily, they didn't have the big boom at the end.

 

[scaesare]

And apparently here we have IM's next lander... anything stand out to you?