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NASA can't figure out what's causing computer issues on the Hubble telescope

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Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#231

Post by retrac »

baryphonic wrote: post #91
fouric wrote: post #17

I know that, at different times, NASA has used Forth[1] and Lisp[2] in some of their space applications. Both of these languages offer REPLs that generally accelerate the debugging process, and while your "average" Lisp might be unsuitable for hard real-time applications (due to the presence of a garbage collector, usually without the hard real-time constraints that you can get out of garbage collectors with extreme…

> while your "average" Lisp might be unsuitable for hard real-time applications (due to the presence of a garbage collector, usually without the hard real-time constraints that you can get out of garbage collectors with extreme effort), I wonder if they have some equivalently interactive system on-board the while your "average" Lisp might be unsuitable for hard real-time applications (due to the presence of a garbage…

I've seen at least one implementation that uses explicit regions; before doing something with say a bunch of cons operations, you allocate a region, all the evaluation is done in the region, it returns a result to the parent region, and the region is then manually dropped, freeing the space used. Set up another region for the next large evaluation and so on.

Almost C style, and I'm sure just as error prone, but it seems like it could work.

https://github.com/wolfgangj/bone-lisp

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#232

Post by Freestyler_3 »

omikun wrote: post #217
pc86 wrote: post #195

Earlier quoted context omitted.

It's arguably even worse than just commenting "This." At least that is small enough you can scan over it and barely even register its existence. But this fedora-tipping "Thank you kind sir this is the type of Internet Content I enjoy!" doesn't even afford you that luxury.

How could it have been reworded to avoid the "fedora-tipping" connotation? I'm being sincere here since I also appreciate book recommendations and I get probably half my book recommendations from HN.

I think the point is to instead of using the keyboard, use the mouse to click the up arrow, and leave it at that. (I know how tempting it is to reply quickly to something, I have the urge to just post whats going on my mind right away unfiltered. So I am very forgiving, but not everyone is)

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#233

Post by belter »

They have two computers:

- First they had a DF-224 flight computer and a - Science Instrument Control and Data Handling (SI C&DH)

Initially DF-224 between missions got installed a coprocessor: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/Co...

During another servicing mission they replaced it with something called the Advanced Computer with Intel 80486: https://asd.gsfc.nasa.gov/archive/hubble/a_pdf/news/facts/FS...

It looks like its about 50,000 lines of code in the C and Assembly programming languages.

https://www.nasa.gov/pdf/327688main_09_SM4_Media_Guide_rev1....

Fig 5-10 is the Data Management Subsystem

https://asd.gsfc.nasa.gov/archive/sm3a/downloads/sm3a_media_...

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#235

Post by grumple »

AnIdiotOnTheNet wrote: post #88
beerandt wrote: post #38

Earlier quoted context omitted.

>"The rule of thumb is when something is working you don't change it," Hertz said. "We'd like to change as few things as possible when we bring Hubble back into service."

A lesson not taught to any modern software developer. Instead they change things all the time for no real reason other than that they want to change things.

This is not true. If something's working, you don't change it for no reason.

Business requirements and requests change all the time. 90% of our work is done in response to that. The other 10% is fixing up technical problems due to increased scaling or bugs found, and then basically never do we upgrade a system to keep up with security updates or change to a more modern tech.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#237

Post by jandrese »

hindsightbias wrote: post #222
jandrese wrote: post #92

Earlier quoted context omitted.

Hubble is basically a repurposed spy satellite so it may still be sensitive. Although I doubt any of its sisters are still flying.

They are believed to have lifespans as long as Hubble. The last block 4 was launched in 2013. https://en.wikipedia.org/wiki/USA-245 USA-314, launched this year, is allegedly a KH derivative.

Hubble has only lasted as long as it has because it was serviced on 4 separate occasions--although one of those was to fix a manufacturing defect. I don't think any of the spysats had service missions.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#238

Post by seanc »

macksd wrote: post #201
qzw wrote: post #7

pushes up glasses I would watch the heck out of a Twitch stream of their debugging/brainstorming sessions. I always loved the movie Apollo 13 , especially the technical troubleshooting parts.

Honestly that movie is a lot of why I got into math and engineering. Jim Lovell was undeniably a badass but I watched that movie and thought the heroes were the ones reading telemetry off a computer screen and using their slide rule to figure out what to do. I hope Hidden Figures does that for another generation.

Like John Aaron, the steely eyed missile man!

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#239

Post by r_police »

gentleman11 wrote: post #202
NeutronStar wrote: post #176

Earlier quoted context omitted.

What did that comment actually bring to the conversation?

Occasionally, very occasionally, it’s nice to read somebody just expressing enthusiasm instead of just posting a clever counter argument. It’s like a spice that you only want a little of but that’s still nice

I mean, you could watch the same news on r/news if you want to see that kind of comments. We don't do that here, and tourists always try to emulate their customes but it is still wrong.

Just commenting as a person with many years on this platform.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#240

Post by [deleted] »

desktopninja wrote: post #199
desktopninja wrote: post #62

I wonder if NASA would welcome a live worldwide collaboration to try solve this problem.

I doubt we (humans) can be respectful enough to each other in truly a global event where an individual partakes in the war room. What I'm thinking here is, and I admit a rather simplistic view ... here is the problem; here is how to observe/debug, submit what you think would be the solution. This would be reviewed/vetted. Most likely school/college/university teams knowledgeable in the subject matter would be the "in…

[deleted]
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