Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Old software keeping space missions alive

bbc.com

Post reply on HN
Print view View original

41–50 of 67 posts

Re: Old software keeping space missions alive

#41

Post by dang »

snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

Ok, I've taken the ancient technology out and replaced it with old software in the title above. Thanks!

Re: Old software keeping space missions alive

#42

Post by neilv »

> Launched almost 46 years ago in 1977, the twin Voyager probes continue to send back data from beyond the Solar System.

> I checked with Nasa, which has assured me that the spacecraft are still being controlled from the same beige cubicle in an annex of its Jet Propulsion Laboratory (JPL) that I visited in 2017, marked with a homemade cardboard sign reading: "Mission critical hardware – PLEASE DO NOT TOUCH".

I throw around the term "mission critical" maybe too easily. Because that beige cubicle with the homemade cardboard sign sounds humbling.

Re: Old software keeping space missions alive

#43

Post by weinzierl »

snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

The article is bad but the premise is not wrong. The things that fly and a lot of the things that stay on the ground are analyzed with NASTRAN whose solver kernel dates back to 1964. At its heart it is still the old FORTRAN code because reproducibility is king.

Re: Old software keeping space missions alive

#44

Post by deepspace »

justinator wrote: post #5
snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

There's a little more to it. If your original team retires because of old age, that's a lot of wisdom lost. Not everyone wants to learn COBOL to keep planes in the air and the IRS running, imagine needing to figure out the low level code on something millions of miles away with half the hardware broken, the battery cracked and leaking – and if the software update doesn't work, the entire mission is over? It's altoget…

The article calls software from the 90s "old". Nobody used COBOL for mission-critical software at that time. There is embedded software I wrote in the 80s and 90s still running in the field, mostly written in C.

Re: Old software keeping space missions alive

#45

Post by hilbert42 »

AlanYx wrote: post #6
hilbert42 wrote: post #3

How about traveling-wave vacuum tubes from the pre-transistor era. Doesn't Voyager use them to generate its RF transmission power?

It does! But the really interesting thing is that travelling wave tubes are still being used for quite a few modern satellite designs. For example, SiriusXM used them in SXM-9/10, and is probably using them in SXM-11/12.

In recent years I've occasionally wondered what the type/part number of that TWT is. Given its history, its heater and cathode emission seems to have held up remarkably well.

Another question I'd like answered, do the Voyagers cycle down or turn off the heater during TX downtime? Turning it off risks metal/cycling fatigue, leaving it on risks reducing the cathode life—or even poisoning it from stray ions.

A final point, presumably the TWT's output has dropped over the decades, how is this monitored and do we know the percentage drop in power output (from the TWT not the Pu power source)?

The fact the TWT is still working seems quite remarkable—but then perhaps I shouldn't be overly surprised, one of my TV sets, a 23" Sharp, is 43 years old and the CRT still works well (and it's switched on for several hours every day).

Re: Old software keeping space missions alive

#46

Post by mosselman »

snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

I find one of the subtitles for one of the images strangely worded too:

“The Voyager space missions were maintained by technology that would today be artefacts in a museum”

The technology either is or isn’t in a museum right now. Why say “would today be”. If it is you can say “technology that by now you can see in a museum” and if it isn’t you could say “expect to be in a museum”.

Re: Old software keeping space missions alive

#47

Post by FetusP »

WalterBright wrote: post #24
mikestew wrote: post #17

Earlier quoted context omitted.

Why would anyone need bolt cutters to extract the drives? I've had PC cases that had eyelets for a lock. You'd have to get through that before "unscrew(ing) the drives".

The drives aren't password protected. Why would one need to take the drives apart? Besides, the text was about extracting the drives, i.e. taking them out of the computer box.

Maybe to access the drive, they have to go through a lockable case. If someone lost the keys to that case, they might have had to pop the locks with a bolt cutter

Re: Old software keeping space missions alive

#48

Post by hilbert42 »

3pac wrote: post #28
hilbert42 wrote: post #3

How about traveling-wave vacuum tubes from the pre-transistor era. Doesn't Voyager use them to generate its RF transmission power?

It also has a vidicon tube for gathering images, although that can no longer be switched on.

Do we know the reason? Heater/cathode failure or HV supply would be likely reasons, or is there now insufficient power from the Pu source to run it?

(The HV supply on a vidicons is usually about 700V—that's high enough to be quite stressful on P/S components.)

Re: Old software keeping space missions alive

#49

Post by hilbert42 »

dr_orpheus wrote: post #36
CoastalCoder wrote: post #19

Earlier quoted context omitted.

Slightly tangential, but if money were no object, do vacuum tubes or solid-state amps have a longer service life in this kind of application?

Theoretically, solid state amplifiers would have a longer service life. Vacuum tubes will always have cathode depletion causing them to degrade eventually (although this is pretty well controlled in most cases for long life). In space though the answer might become more complicated. Because the vacuum tubes are more tolerant of high voltages, they are probably also more tolerant of charge build-up and discharge from…

That makes sense, also it's likely solid state devices would be more susceptible to cosmic rays, high velocity protons, which could cause catastrophic (instant) failure whereas TWTs would be unaffected.

I wonder if you may know any answers to questions I put to AllanYx ?

Re: Old software keeping space missions alive

#50

Post by [deleted] »

FetusP wrote: post #47
WalterBright wrote: post #24

Earlier quoted context omitted.

The drives aren't password protected. Why would one need to take the drives apart? Besides, the text was about extracting the drives, i.e. taking them out of the computer box.

Maybe to access the drive, they have to go through a lockable case. If someone lost the keys to that case, they might have had to pop the locks with a bolt cutter

[deleted]
Post reply on HN