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What computer and software is used by the Falcon 9? (2015)

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Re: What computer and software is used by the Falcon 9? (2015)

#111

Post by thebruce87m »

Nokinside wrote: post #59
nullifidian wrote: post #15

Sounds kinda disappointing/irresponsible. Chromium is an overly complex, relatively buggy piece of software. For example I recently experienced a bug where a text I selected was significantly offset from what should have been selected given the pointer position (on linux), a misclicky kind of bug. Considering that the majority of Crew Dragon's controls are through touch screen, maybe even manual docking(not sure, but…

Most safety critical code in the world, both civilian and military, is currently written in C/C++. Ada/SPARK is also used but it 's below 50%. These languages have the best practical static code analyzer, verification and proofing tools money can by. I'm personally using Astree https://www.absint.com/astree/index.htm Auto­matic docking software for the ATV that delivers supply to ISS is written using C code and verif…

How much is Astrée? I get nervous when you can’t see a price on the website.

Re: What computer and software is used by the Falcon 9? (2015)

#112

Post by azhenley »

qchris wrote: post #100

Knowing that the ground control software is written in LabView is one of the more disappointing things I've read recently. I did a bunch of test engineering during co-ops during college, including multiple "codebases" of LabView, plus the normal class coursework and research lab instrumentation. I hate LabView, to the degree that I made a commitment never to apply to a job that has it's use as one of the requirements…

Having worked at National Instruments, I will say there are some engineers out there that really love LabVIEW. It has been a successful tool.

Re: What computer and software is used by the Falcon 9? (2015)

#113

Post by tonyedgecombe »

peter303 wrote: post #98

Other references say parts of Falcon9 and Dragon a version of Unix calLed VxWorks from Charles River. It is realtime (not virtual) and predates Linux. NASA uses it in a lot of its space probes because its been debugged for 33 years. That doesnt means its perfect. The two 2003 Mars rovers experienced a bug in the then-newfangled flash memory driver. It was successfully fixed and reloaded from Earth. https://en.wikiped…

VxWorks from Charles River

I think it is Wind River Systems.

Re: What computer and software is used by the Falcon 9? (2015)

#114

Post by BiteCode_dev »

dilyevsky wrote: post #107
peter303 wrote: post #98

Other references say parts of Falcon9 and Dragon a version of Unix calLed VxWorks from Charles River. It is realtime (not virtual) and predates Linux. NASA uses it in a lot of its space probes because its been debugged for 33 years. That doesnt means its perfect. The two 2003 Mars rovers experienced a bug in the then-newfangled flash memory driver. It was successfully fixed and reloaded from Earth. https://en.wikiped…

I’ve worked with vxworks and I don’t think it can be considered Unix unless something changed in last 10 years

Can you give some details about the experience?

I'm curious about this system, but not curious enough to spend a week playing with it.

Re: What computer and software is used by the Falcon 9? (2015)

#115

Post by jccooper »

qchris wrote: post #100

Knowing that the ground control software is written in LabView is one of the more disappointing things I've read recently. I did a bunch of test engineering during co-ops during college, including multiple "codebases" of LabView, plus the normal class coursework and research lab instrumentation. I hate LabView, to the degree that I made a commitment never to apply to a job that has it's use as one of the requirements…

That AMA is from 2013, when LabView would have seemed like a more reasonable choice. Dunno if they've changed since then, but it's possible they've come to their senses.

Re: What computer and software is used by the Falcon 9? (2015)

#116

Post by BiteCode_dev »

jonplackett wrote: post #108
BiteCode_dev wrote: post #99

Earlier quoted context omitted.

It reminds me of this olognion piece: https://www.theolognion.com/unreal-engine-5-is-meant-to-ridi... That's not just hilarious, that's also pretty close to how I feel most of the time. I mean, some people have built the Airbus A380. On the other hand, last week, I created a test DB with the user "test" and the password "test". I couldn't connect to it, and after a long debugging session, noticed I misspelled "test".…

Well, that Mars rover missed its target because they got their units of measurement mixed up. https://www.latimes.com/archives/la-xpm-1999-oct-01-mn-17288... So, don’t feel too bad...

It does feel better knowing my mistake didn't cost $125-million dollars.

Is there a book that lists many bugs and weird IT stories? Like the 500km email or the FileNotFound boolean.

Re: What computer and software is used by the Falcon 9? (2015)

#117

Post by Czarcasm »

yellowapple wrote: post #70
stefan_ wrote: post #45

Earlier quoted context omitted.

The fact that it's implemented in JavaScript and Chromium just tells you the fancy display is entirely superfluous to mission success.

Is there a backup should that fancy display fail? If not, then I'd hardly call it "superfluous to mission success".

Apparently the physical controls below the screens can perform all of the mission critical functions in the event of a display failure.

Re: What computer and software is used by the Falcon 9? (2015)

#118

Post by scotty79 »

vertex-four wrote: post #66
davedx wrote: post #43

Earlier quoted context omitted.

You haven’t made any arguments about why Javascript isn’t good for building UIs there. Here’s mine for why it is: - first class functions (callback style is a good fit for UI programming) - async/await and single threaded - many components of UIs are async by nature, Javascript supports you well here while keeping things simple with its single threaded model

There's... a large number of languages with both of those features.

Could you name few better than js?

Re: What computer and software is used by the Falcon 9? (2015)

#120

Post by qchris »

bmitc wrote: post #109
qchris wrote: post #100

Knowing that the ground control software is written in LabView is one of the more disappointing things I've read recently. I did a bunch of test engineering during co-ops during college, including multiple "codebases" of LabView, plus the normal class coursework and research lab instrumentation. I hate LabView, to the degree that I made a commitment never to apply to a job that has it's use as one of the requirements…

How well do you actually know LabVIEW? Have you ever used its object-oriented system, actor framework, network streams, or get/set control value by indices (a feature actually implemented for SpaceX) functionalities? These are all things a professional LabVIEW engineer will be familiar with and use. The fact that a system didn't use these means it's either seriously outdated or the person writing it wasn't aware. It…

This is definitely fair--I don't consider myself a LabView expert. I'm proficient with object-oriented systems (Python, C++, Rust (if you consider Rust object-oriented)), with get/set for indices and network streams, but not familiar with actor frameworks outside of a passing read-some-docs a few times. I'd estimate I've cumulatively spent around a month working on LabView full-time, including writing/editing several working instrumentation sets in different settings.

I don't like LabView because of the when-properly-architected asterisk. Sure, well-written code doesn't happen all the time in any language, but my personal experience is that the both the frequency and severity of that being the case is much higher in LabView than any other language I've used, making the barrier to entry for writing good code essentially being close to a full-time LabView engineer.

You'll get no argument that it can do a good job when it's written well--the good LabView VIs I've used are definitely fast, and as you pointed out, NI makes sure that it plays well with hardware. But, to me, the risk of getting hired somewhere with a poorly-constructed system written in LabView is far too high, considering the grief I've had trying to fix those system.

I appreciate your suggestions for other alternatives--I haven't personally used C#/.NET a lot, but I know several test engineers who love it enough to do all their GUI work in it. I'll keep it in mind next time I'm setting up a DAQ system!

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