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Thee are a bunch of comments here asking why one would run Windows on a spacecraft. I am a spacecraft engineer. I don’t see anything in the linked article indi
by GlenTheMachine 2y ago
Thee are a bunch of comments here asking why one would run Windows on a spacecraft.
I am a spacecraft engineer. I don’t see anything in the linked article indicating that they are actually running Windows - the BSOD claim is tongue-in-cheek, or at least that’s how I read it. I also don’t know of anyone anywhere that runs Windows on a spacecraft, with the exception of laptops used by astronauts. Typically one runs vxWorks, or maybe QNX. Some experimental (high risk, low cost) systems run Linux. Older spacecraft don't run any OS at all, everything is running on bare metal, and that may be true for a handful of current spacecraft as well.
Windows is used in some places by ground controllers, but these days they tend to be running Linux a lot more often.
- TrueDuality 2y agoSeconding the vxWorks and bare metal. Never seen Windows or Linux on a satellite bus. Haven't really touched payloads but I've seen some wonky things shipped to orbit by universities and not all them have been cubesat student projects.
- nicce 2y agoEvery Starlink runs with Linux. The license list is a bit long: https://www.starlink.com/assets/pdfs/Starlink-Open-Source-Components-License-Notices.pdf https://www.starlink.com/assets/pdfs/Starlink-Open-Source-Co...
- MichaelZuo 2y agoIt's surprising they didn't pick a RTOS.
- gosub100 2y agoWhy? What benefit would that give them?
- deleted 2y ago[deleted]
- karlgkk 2y agoI can't tell if this a serious comment or not, but they need an OS with realtime guarantees. They have claimed to use linux in a rtos configuration, also probably have a redundancy and voting-based failover system.
- gosub100 2y agoI can't tell if this is a serious answer to the question or not, as you have answered it in terms of the question: "why the need for RTOS? -> because they need RTOS". Stop wasting time with replies like this that add no value.
- karlgkk 2y agoIf you can’t understand why the control system for SOMETHING GOING TO SPACE needs an RTOS then I can’t even begin to have a conversation with you
- karlgkk 2y agoThey did.
- MichaelZuo 2y agoHow? That was a very recent change to linux.
- wrs 2y agoIt was merged to mainline Linux last week. The patches have been usable for many years if you compile a custom kernel.
- MichaelZuo 2y agoIt’s not quite Linux anymore if it’s a custom kernel…
- karlgkk 2y agoYeah, usually it has a vendor brand slapped on it tbqh
- fennecfoxy 2y agoWhy? I doubt that Linux controls everything. I imagine it's used for the core higher level functions of the satellites themselves, but I'm sure processes running in Linux will eventually comms with lower level hardware that is indeed running an rtos or similar. In the same way that any pi project should really use i2c or spi to comms with hardware that's more purpose designed.
- cobalt 2y agothat doesn't state what uses linux, angular.io is also on there
- mrpippy 2y agoThat's likely software for the receiver/router/CPE that customers use, since it's being distributed they have to satisfy license obligations for it. Software actually running on satellites isn't being distributed, so there's no license obligations there (unless it's AGPL, ha!)
- nicce 2y agoIt includes that software too, but they have claimed that they use Linux, so I would assume that some software is from the satellite itsef as well. It is still not clear ”what” obligations you have for a piece in the space.
- lofaszvanitt 2y agoYeah, why would a satellite have angular...
- inamberclad 2y agoI've used Linux on the payload processor computer of a spacecraft so I know it happens :P I've also worked with a payload running Windows Embedded.
- jdiez17 2y agoLinux on a satellite bus is definitely up and coming. For example ESA's OPS-SAT ran the NanoSat MO Framework (https://nanosat-mo-framework.github.io/ https://nanosat-mo-framework.github.io/), written in Java and running on an ARM Linux OBC. It also makes a lot of sense for payload computers. I'm working on a Linux distribution for space applications that addresses some of the pain points (application deployment, software update & memory-safe implementations of typical space protocols like CCSDS/PUS). If all goes to plan it will fly on a 1U CubeSat tech demonstrator this year, a cybersecurity research 1U CubeSat next year, and a 2U high performance satellite ... later. :)
- zanthras 2y agoLinux(with realtime patch) is used very heavily in spacecraft by Spacex. So both in terms of high visibility/important/danger (dragon 2) and high count (starlink) it is very widely used. citation https://old.reddit.com/r/spacex/comments/ncj4vz/we_are_the_spacex_software_team_ask_us_anything/gy8xyzh/ https://old.reddit.com/r/spacex/comments/ncj4vz/we_are_the_s...
- XorNot 2y agoI wonder how the integration of PREEMPT_RT is going to affect that technology stack going forwards (I imagine slowly, but it's there now).
- yndoendo 2y agoSave costs by integration with the new feature or increasing cost with maintaining a custom kernel branch in the long run.
- chupasaurus 2y agoIt was merged to mainline a week ago.
- bboygravity 2y agoAnd apparently the astronaut !touchscreen! GUI is written in Javascript (not a joke).
- lisper 2y agoThe author of TFA clarifies here: https://news.ycombinator.com/item?id=41651715 https://news.ycombinator.com/item?id=41651715 TL;DR: the spacecraft is indeed not running Windows. It's running a custom OS written in C.
- yashap 2y agoIndeed, and it’s clearly stated in the article: > Safemode is the satellite equivalent of a blue screen of death. It’s about avoiding safemode, and more generally about the end-to-end QA/testing process for satellites before they’re sent up into orbit. It’s very clearly not about actual Windows BSODs, it’s just written in a tongue-in-cheek style. Those commenting about “wtf windows on a spacecraft” clearly didn’t read the article, just read the title. FWIW I found the writing style engaging and the content interesting. I guess the title is a little click-bait-y, but not in a way that I minded much, and I probably wouldn’t have read an article titled “How to avoid safemode on a satellite.” It’s a fine line, but titles DO have to draw you in, otherwise you’ll never read the article. Re: the article itself, I did think it was pretty wild that customers have to be informed of every incident where a satellite flips into safemode in TESTING! In real operations, sure, but in testing, that’s wild. Feels like having to report bugs caught in my local dev environment, that were never deployed to prod.
- GlenTheMachine 2y agoThis would be during formal testing, which is similar to what you might know as “acceptance testing”. The spacecraft doesn’t “enter safe mode” during development. If you’re paying two billion $ for something you become very very interested in test design and test results. Also, safe mode isn’t really the same as a BSOD. It’s a mode where the spacecraft decides something is wrong and disables a lot of functionality and focuses on pointing the solar panels at the sun and the antennas at the ground. It does not cease functioning - if that happens, you’ve probably lost your spacecraft. It is therefore VITALLY IMPORTANT that safe mode works, and a smart program manager tests the hell out of it.
- Brian_K_White 2y agoSo it's a bsod that switches to safe mode instead of halting. We already got that it's not actually Windows and so not literally identical to bsod in every detail. It's not the same as a common os safe mode either because it happens by itself as the last resort response to a problem, like a bsod. Not just on command.
- 2y ago
- firecall 2y agoSo could this finally be the year of Linux on the Moon? ;-)
- Fnoord 2y agoWhich OS do the Mars rovers run?
- GlenTheMachine 2y agovxWorks
- garaetjjte 2y agoThe helicopter ran Linux.
- freedomben 2y agoI worked on UAVs in the late 00s and early 10s and it was all VxWorks as well. We were playing around with some embedded Linux but it wasn't used on anything "serious," despite some of our dreams.
- rob74 2y agoWell, it's a fair question, because the article jumps right into extremely detailed specifics like "Closed Loop Tests" that probably just people working in this domain are familiar with, without first making clear what exactly it's talking about. "The lifecycle of most spacecraft consists of a final phase" - as someone with only a cursory knowledge of spacecraft, at this point I assumed he would be talking about deorbiting?
- deleted 2y ago[deleted]
- TacticalCoder 2y ago> Thee are a bunch of comments here asking why one would run Windows on a spacecraft. Because TFA is highly misleading > I don’t see anything in the linked article indicating that they are actually running Windows TFA literally begins with a picture of a Windows BSOD with a Windows error message.
- metadat 2y agoIs there any open-source equivalent to QNX?
- GlenTheMachine 2y agoNo, unfortunately. QNX was itself not exactly open source, but at least used a “source code available for inspection” model and apparently had a fantastic user community. Then it got bought by RIM (BlackBerry). The source code went away and the owners stopped responding to the user community and the whole thing basically became irrelevant.