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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

#221

Post by trothamel »

cameldrv wrote: post #196
trothamel wrote: post #120

Earlier quoted context omitted.

If you want to see debugging a computer in space, check out Apollo 13's sequel, Apollo 14. The moon landing is being held up by shorted-out switch that's causing the LM to abort the landing, and it's up to the programmers back home to figure out how to work around it in time to allow the landing. Apollo 13 was the story of a 'successful failure', while Apollo 14 shows how hard work and creative thinking can turn fail…

Don Eyles' book Sunburst and Luminary has a chapter on this, and Don was primarily responsible for the Apollo 14 workaround. The book is also generally just a fantastic account of what it was like to develop software for the Apollo Guidance Computer.

Also about living through the sexual revolution. It's a really interesting book, but as much of a memoir as a technical book.

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

#222

Post by hindsightbias »

jandrese wrote: post #92
recov wrote: post #58

Earlier quoted context omitted.

Interesting thought. I would say something like the hubble transcends politcal/governmental boundaries... although I do wonder how much if its software is used in other secretive satellites.

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.

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

#223

Post by belter »

bencollier49 wrote: post #148
stakkur wrote: post #146

"If this computer were in the lab, we'd be hooking up monitors and testing the inputs and outputs all over the place, and would be really quick to diagnose it," he said. "All we can do is send a command from our limited set of commands and then see what data comes out of the computer and then send that data down and try to analyze it." They've just mostly described my career.

Still probably faster than deploying to AWS.

"According to NASA, the 3 computers aboard the Hubble Space Telescope contain over 50,000 lines of code in the C and Assembly programming languages." https://www.leeholmes.com/writing/hubble.pdf

I am going to go out on a limb here and post my diagnostic: There is some global counter that overflow as the system was not rebooted for a while...NASA...take it from here :-)

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

#224

Post by diamondo25 »

3pt14159 wrote: post #197
diamondo25 wrote: post #121

Earlier quoted context omitted.

The amount of preparation is much, much more than every other "accessible" installation. Typos are the worst to recover from, backspace usually doesnt exist. As I've sent commands to our Linux-running satellites, its usually prepending your commands with ctrl-c characters and a couple newlines at the end, just to make sure it runs and nothing is left in the buffer. There is also a possibility that commands get execut…

I'm surprised theres no error correction in your uplink. Crazy.

It depends on the API. If your API is "put this data over uart to the TTY", and the uart of the device is overloaded and drops characters... Or maybe mangles characters due to bitflips. Or what have you. Its all possible!

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

#225

Post by falcrist »

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.

It's worth noting that the people in that movie were WAY more loud and emotional than the real NASA engineers and operators.

You can see how NASA people react to tough situations by watching the videos of mission control during the Challenger and Columbia disasters. No shouting. No arguments. Just cool professionalism and restrained emotions.

They have a job to do, and they do it well even under stress. "Steely-eyed missile men/women" indeed.

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

#226

Post by etskinner »

boardwaalk wrote: post #140
35fbe7d3d5b9 wrote: post #107

Earlier quoted context omitted.

One of the best senior engineers I worked with taught me how to run an outage. The most important thing? Stop what you are doing, take charge, and get everyone else to stop what they are doing. The best case scenario of a bunch of engineers flailing about on a bridge turning knobs is that you luck into a fix but don't know how you got there. But you're more likely to make things worse.

Sounds like “locking the doors” (Space Shuttle disasters). Although, there was really not much to recover from there.

I hadn't heard of this before, chilling but cool: https://www.theguardian.com/world/2003/feb/13/columbia.space...

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

#227

Post by mkr-hn »

abnry wrote: post #95
keanebean86 wrote: post #74

Earlier quoted context omitted.

This would be cool for earth satellites. On the other hand watching a stream involving something on Mars, let alone voyager, would be pretty boring! Send: ls Ok let's take a 20 minute break.

Job Posting: NASA programmer, needs at least 1 wpm typing speed and experience with compiling large projects.

Time to bring back flowchart templates.

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

#228

Post by diamondo25 »

bentcorner wrote: post #183
diamondo25 wrote: post #121

Earlier quoted context omitted.

The amount of preparation is much, much more than every other "accessible" installation. Typos are the worst to recover from, backspace usually doesnt exist. As I've sent commands to our Linux-running satellites, its usually prepending your commands with ctrl-c characters and a couple newlines at the end, just to make sure it runs and nothing is left in the buffer. There is also a possibility that commands get execut…

Isn't there some way to ensure that what you typed is what is being executed? Dropping characters from the terminal sounds terrifying. I don't know enough about ssh and terminals to know if it's possible to type "12345" and see "12345" echoed back to me but really what the remote session sees is "1245".

Yes, terminals usually echo back the characters. In our case this would be buffered and we could request the buffer. But that would still take some operations. Best way, usually, is to send a bunch of commands in a way you ensure proper order of execution (eg write a file, check checksum of file, execute file), and make sure you can pull the logs afterwards.

Nowadays, links and systems get easier to work with, and you can sometimes have a literal TTY open to the system, like Reactor Hello World has ( https://reaktorspace.com/reaktor-hello-world/ ). However, this is over S-band, which is a 2Mbit/s link, so overhead for a stable TTY (or ethernet connection) is a lot less than using UHF/VHF.

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

#229

Post by diamondo25 »

abnry wrote: post #147
diamondo25 wrote: post #121

Earlier quoted context omitted.

The amount of preparation is much, much more than every other "accessible" installation. Typos are the worst to recover from, backspace usually doesnt exist. As I've sent commands to our Linux-running satellites, its usually prepending your commands with ctrl-c characters and a couple newlines at the end, just to make sure it runs and nothing is left in the buffer. There is also a possibility that commands get execut…

Very fascinating! You haven't happened to written a blog post or something on this, have you? I am sure HN would love reading about it.

Sorry, I did not. There are plenty of stories on the internet about cubesats, they get launched by universities even :)

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

#230

Post by retrac »

mietek wrote: post #106
baryphonic wrote: post #91

Earlier quoted context omitted.

> 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…

How about a Lisp without the need for garbage collection at all? http://web.archive.org/web/20020331165324/http://home.pipeli...

Ah, Rust's grandparent!
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