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My $500M Mars rover mistake

chrislewicki.com

31–40 of 361 posts

Re: My $500M Mars rover mistake

#31
post #12

Are the electronics in these rovers really so bespoke that they don't have multiple copies of each electronic component warehoused on-site? I'd expect that the rover body itself would be bespoke this late in the process, although a parallel test vehicle would be useful, do they have that?). But in case someone fried the rover's electronics I'd think tearing it apart and replacing them while maintaining the chassis sh…

Typically your best bet is going with a provider that already produces whatever item, isn't bespoke to that particular program, and has an assembly line of sorts already set up. However the other problem is they are often built in low numbers to begin with so getting hold of a flight qualified unit will most likely be an issue as well. Also everything is tightly packed together which usually makes replacing something involve messing with a bunch of other items.

Re: My $500M Mars rover mistake

#32
One thing about long aerospace missions like this with huge lead times that always gets me - you can spend years of your life working on a mission, only for it all to fail with potentially years until you can try again.

This is a refreshingly humanizing article, but is also one written from the perspective of a survivor. Imagine if the rover were actually lost. I asked the question "what would you do if the mission failed after all of this work? How could you cope?" to the folks at (now bankrupt) Masten Aerospace during a job interview, and maybe it was a bad time to ask such a question, but I didn't get the sense they knew either. "The best thing we can do is learn from failure," one of them told me. An excellent thing to do, but not exactly what I asked. This to me stands out as the defining personal risk of caring about your job and working in aerospace. Get too invested, and you may literally see your life's work go up in flames.

Re: My $500M Mars rover mistake

#33
post #6

Why would you ever allow people to work 12-hour days on something so important? Grad student labour is cheap, surely trying to have one person do the work of two is a false economy.

On your next hospital visit for life-saving care, I'm sure you will be comforted to know that nurses (in the US) typically work 12 hour shifts and they're on their feet the whole time.

Re: My $500M Mars rover mistake

#35
post #9

Earlier quoted context omitted.

So the work is too important to work 12 hour shifts on it, yet your solution is throwing “cheap” grad students at it?

Wait until I tell you who's doing work in hospitals and how much they're being paid for it.

Another relevant bit of info from hospital accidents: hand-offs between shifts are known to increase the risk of a mistake in care and are part of the reason nurses and doctors work such long hours.

Re: My $500M Mars rover mistake

#36

How is this a $500 million mistake? It seems the issues didn’t cost $500 million.

I guess the idea is that it potentially could have cost $500 million therefore it was a $500 million mistake. It's not exactly accurate but it does help contextualize the gravity of their mistake.

Reminds me of my favorite George Carlin bit[1]:

Here's one they just made up: "near miss". When two planes almost collide, they call it a near miss. It's a near hit. A collision is a near miss.

[1]: https://www.quotes.net/mquote/35854

Re: My $500M Mars rover mistake

#37
post #6

Why would you ever allow people to work 12-hour days on something so important? Grad student labour is cheap, surely trying to have one person do the work of two is a false economy.

On your next hospital visit for life-saving care, I'm sure you will be comforted to know that nurses (in the US) typically work 12 hour shifts and they're on their feet the whole time.

And doctors doing 24h shifts. At least in the NICU my kids were in.

Re: My $500M Mars rover mistake

#38

Ohhhh I hate things that you “just have to not screw up.” A fiddly manual process with so many possible ways to screw something up is almost guaranteed to see a catastrophic failure. If this really manual fiddly process was really the only way they could test the motors, I’d say that’s a big failure on the design engineer’s part.

Test requirements often arise after system design is complete. Engineers need time to examine the system, theorize failure modes, and design the tests. Also time to test the system, find some unexpected failure mode, and then design yet more tests.

Re: My $500M Mars rover mistake

#39
post #6

Why would you ever allow people to work 12-hour days on something so important? Grad student labour is cheap, surely trying to have one person do the work of two is a false economy.

I have bad news for you about health care professionals.

Re: My $500M Mars rover mistake

#40

Ohhhh I hate things that you “just have to not screw up.” A fiddly manual process with so many possible ways to screw something up is almost guaranteed to see a catastrophic failure. If this really manual fiddly process was really the only way they could test the motors, I’d say that’s a big failure on the design engineer’s part.

Or it just needs a budget that can dramatically increase and/or have a deadline that can continue to be pushed back to allow for corrections. As exhibit A, I'd like to present the james webb space telescope.
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