linebeck (u/linebeck)

linebeck commented on GeoDeep's AI Detection on Maxar's Satellite Imagery tech.marksblogg.com/geode... · Posted by u/marklit

linebeck · 8 months ago

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 commented on What We Lose When Our Memories Exist in Our Phones bloomberg.com/news/articl... · Posted by u/JumpCrisscross

jasode · 9 months ago

>As objects, paper tickets serve as proof of past lives long after their brief utility as proof of payment. I sat with my accidental time capsule for more than an hour, doing what my teenage self had probably hoped I might: linking each one to a buried memory as best I could. [...] But most of the tickets I’d bought myself, in person and almost always with cash, at box offices or the Ticketmaster counter at the local grocery store. They looked like they’d been printed on a machine even older and more obsolete than the “Ticketmaster counter” as a concept. You don’t need to be a techno-pessimist to acknowledge that digital tickets, for all their advantages in transferability and traceability, don’t serve this long-tail purpose.

I did the exact opposite. I hung onto a bunch of paper TicketMaster stubs for decades because I was indecisive about throwing them away or hanging on to them. The "sentimental baggage" surrounding those tickets distorted my thinking and attached too much importance too them.

And then I read about de-cluttering your life advice from minimalists and learned of a good hack that worked for me: Just take photos of your mementos and then throw them away.

That was the psychological breakthrough I needed. I digitally scanned all my old Ticketmaster stubs as *.tif files and then threw them out. I also had a bunch of useless novelty coffee mugs (free gifts from trade shows or past employers). I just took digital photographs of each mug and then gave them away at Goodwill. Preserving them digitally helped me let go of the physical objects. Everyone once in a while, I might revisit my digital scans of the concert tickets on my computer monitor and that's good enough for me.

Reading passages like hers reminds me that that some people need those physical mementos and some don't. In a similar vein, a lot of people like physical media like DVDs and CDs. In contrast, I got rid of my entire physical library of thousands of discs. I don't miss the space they took up at all.

linebeck · 9 months ago

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 commented on Ask HN: Are YC startups *actually* hiring? · Posted by u/logotype

linebeck · a year ago

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 commented on Ask HN: Predictions for 2025? · Posted by u/uncomplexity_

linebeck · a year ago

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 commented on How to avoid a BSOD on your 2B dollar spacecraft clarkwakeland.com/blog/20... · Posted by u/linebeck

akira2501 · a year ago

Can you speak at all as to how the development on this software is done? Is it distributed with centralized version control? Does release and engineering process interact with the version control at all? Are there mechanisms that link defect reports, corrections, and sign offs back to version control and into the build system?

I got lost recently in how the Shuttle software was managed, mostly through IBM mainframes, and z/OSs facilities for all the above. I'm curious how modern development looks in comparison.

linebeck · a year ago

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 commented on How to avoid a BSOD on your 2B dollar spacecraft clarkwakeland.com/blog/20... · Posted by u/linebeck

Jtsummers · a year ago

> 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.

To the last part first: Good that safe mode kicked in and did the right thing, but now what? What caused it to enter safe mode in the first place?

That's why they care when it happens. If they don't know why it's entering safe mode, they can't correct the actual problems in the system.

linebeck · a year ago

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 commented on How to avoid a BSOD on your 2B dollar spacecraft clarkwakeland.com/blog/20... · Posted by u/linebeck

barbegal · a year ago

Could I ask you to clarify why avoiding safemode is so important? In a non satellite system safemode means everything is driven to a safe state which is fine during testing in the lab.

Also do you not run these tests in an even more simulated environment where there is only the flight computer and no real hardware at all?

linebeck · a year ago

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 commented on How to avoid a BSOD on your 2B dollar spacecraft clarkwakeland.com/blog/20... · Posted by u/linebeck

linebeck · a year ago

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 commented on Detection of an Earth-sized exoplanet orbiting nearby ultracool dwarf star nature.com/articles/s4155... · Posted by u/belter

linebeck · 2 years ago

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!