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linebeck

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How to avoid a BSOD on your 2B dollar spacecraft

clarkwakeland.com
190 points·by linebeck·il y a 2 ans·152 comments

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linebeck
·l’année dernière·discuss
Cool post. I'd be interested in seeing models likes this deployed to the satellites themselves.

Typically, data gathered from satellites needs to wait for the satellite to do a pass over a dedicated ground station before it can be processed, which is probably somewhere in the US. If you move the processing from the ground station to the satellite, then you 1. Don't have to transmit as much data, 2. Can transmit actionable intelligence much faster. It can be upwards of 90 minutes before a satellite passes over it's ground station. If you could get that down to a few seconds, I could see some serious applications in disaster response.
linebeck
·l’année dernière·discuss
I think it's highly dependent on the significance of the memento. I have physical credentials I received for a major athletic event I competed in, and never in my life would I consider taking a picture of them and throwing them away.

It doesn't sound like you were all that attached to the coffee mugs to begin with, in which case digitizing them was a good move.

I'd imagine this is part of the reason why my parents still keep my terrible first grade art pieces framed on their desks.
linebeck
·l’année dernière·discuss
It’s likely they know someone they’ve effectively already offered the job to, but equal opportunity laws require a job posting to be made. So while they are technically “hiring”, the job posting is fairly meaningless.
linebeck
·il y a 2 ans·discuss
Blue Origin's New Glenn achieves successful booster recovery and payload to orbit delivery. Initially this is seen as huge win and they emerge as potential challengers to SpaceX, however manufacturing issues with BE-4 engines and questions about the design choice of New Glenn's massive 7m fairing (when satellites are converging towards smaller, more compact designs) will cause speculation for their product market fit.
linebeck
·il y a 2 ans·discuss
FSW development is done by a different team than mine but I believe it's just managed through gitlab. Releases are done through tags, and any updates that need to be made have tickets created for them and are developed by the FSW team. Final approval is given by certified product engineers and then a new tag is created for that release. Like I said this is a different team but from what I've seen the process is fairly modern given how old our hardware is. I'm not sure of the exact process of how it's loaded onto the satellite through.
linebeck
·il y a 2 ans·discuss
There are faults IDs that trip if certain telemetry goes outside of a normal range. If a safemode were to occur, we would investigate which faults tripped and at what time, and use those to construct a "story" of what happened on the satellite before it entered safemode. We're also constantly recording every telemetry that comes down, so we could reference any telemetry we wanted as far back as months in the past.

To your point, yes you're correct. The cause of the safemode is much more interesting than the fact we entered it.
linebeck
·il y a 2 ans·discuss
Having discussed this same question with the more experienced members of my team, the only conclusion I can draw is that the customer (US Government) is incredibly risk averse. Any unexpected entry into safemode would require a report, multiple meetings with the customer, and them being pretty angry. Their line of reasoning seems to be "Safemode->Something is wrong->Why is something wrong? We're not paying you to be wrong". I'm personally of the opinion that safemode isn't that bad. It's fully recoverable and shows the system is working properly.

We normally have a Functional Test Assembly (real computer and some other hardware for testing) to run our tests against, but we only have one setup and it is consistently unreliable. This particular CLT was unable to get a clean run in the lab but it was decided that the issues were related to the lab setup rather than the actual test, so we moved forward to run on the satellite (against our team's protests).

This to me is the real crux of the issue: if we can't even trust our own testing environment, what's the point of having it at all? If the customer is so risk averse, why would we take this chance? Needless to say, I don't think we'll be running anything on the satellite without full FTA vetting anytime in the near future.
linebeck
·il y a 2 ans·discuss
Author here: I should clarify the satellite is not running Windows. Instead, it’s running its own custom OS written in C called Flight Software (FSW) specifically designed for the satellite onboard computer.

Re-reading the post, I see how the title, my analogies, and poor attempts at humor would give the incorrect description of what’s happening with the satellite when it enters safemode. I’ll amend the post soon.

Thanks for the feedback, I’ll be better next time.
linebeck
·il y a 2 ans·discuss
Exoplanet detection is a very precise measurement. The two main methods we have (doppler shift of host star from the planet's orbit and the transit of the planet across the star) are not exhaustive by any means and biased towards discovering large planets that have short orbital periods. The fact that more Earth sized planets are being discovered and could serve as targets of analysis by JWST is an exciting prospect and I can't wait to see its development!