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XKCD
XKCD
4:11 AM
 
fyrepenguin
fyrepenguin
4:47 AM
@ErinAnne unexpected because apparently they decided to change landing sites after the critical design review. The original site *didn't* have craters/topography like their new site did, and they didn't do due diligence afterwards, apparently
https://spacenews.com/software-problem-blamed-for-ispace-lunar-lander-crash/

> A factor in the crash, he said, was a change in landing sites made after the mission completed its critical design review in February 2021. The mission was originally to land in Lacus Somniorum, a basaltic plain with few craters. That change, he suggested, was not sufficiently tested before launch.
>
> The company changed the landing site “to maximize the benefit of the mission,” he said, for both the company and its payload customers. “This is a payload transportation business, and we need to maximize the paylo…
 
 
5 hours later…
Erin Anne
Erin Anne
9:23 AM
I kind of don't like the message in the end of the Scott Manley video and somewhat in the ispace announcement that the problem is software, rather than specifically navigation
they got bit by a standard filtering technique that they applied without really thinking through what the filter would need to accept and reject
I've already forgotten what other missions Manley quickly recounted failing as also being software-related
but like...at least this one wasn't a problem you solve by hiring better software engineers or computer science PhDs, it could very easily go al the way to the filter requirements
 
 
4 hours later…
TheMatrix Equation-balance
TheMatrix Equation-balance
1:22 PM
Probably as usual - QA (simulator test) issue.

Boeing's 2nd Starliner software glitch.
Issues during the Orbital Flight Test (OFT) mission, particularly when it comes to the spacecraft's software. Along with the previously disclosed error with Starliner's onboard timer, a second software issue could have potentially led to a slight but problematic collision of two of the spacecraft's components, investigators determined.
 
 
5 hours later…
fyrepenguin
fyrepenguin
6:07 PM
@ErinAnne moreover, it’s really kind of a project management failure. From the sounds of it, with the original plan, the software and hardware would’ve been sufficient. It was only after making changes late in the game without doing due diligence that caused the issues
We may never know, but it’s entirely possible that it would’ve had success originally as-designed and planned. I wonder if the assumptions they made regarding the filter were just too tailored to their original landing plan. Not great for a generic lander, but wouldn’t’ve been an issue
I feel like the right play here is to add another hardware rangefinder, or trust the altimeter that already was there since it sounds like it was A-OK
 
 
1 hour later…
Erin Anne
Erin Anne
7:22 PM
Maybe "build the generic lander" should be the lesson here
though that's the opposite of a standard software engineering lesson so maybe not
seeing as how it was a lunar mission they had constant contact with, it also seems like there should be some questions about how the mission was being controlled
I know it was driving itself but it was absolutely being monitored by engineers
surely those engineers had some questions about how the state was being updated, because it seems like they reverted to doing that completely inertially
 

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