5 ms·

Why shuttle Atlantis will not be left attached to the ISS

151 points by soundsop 15y ago

noonespecial 15y ago
Last chance for the Americans to bring down any secret stuff that was on the station?
- joeyh 15y ago
  There does not seem to be any impediment to anyone of any nationality, including space tourists, visiting any part of the ISS, so color me doubtful on that theory. People do seem to avoid the cramped Russian side mostly, and who knows what goes on socially that NASA PR hides from us. Anyway, the US military has their own, apparently unmanned, shuttle replacement and do plenty of launches of secret stuff on conventional rockets. This is not surprising when you consider the relative budgets. Disposing of the station's trash seems a large enough logistical problem that getting one more shuttle-load out could be the real motivator. Sorta sad to think that the last shuttle will be essentially a garbage scow on landing. At least they didn't stuff it to the gills and send it down to burn up on reentry, like is done with the majority of craft that dock to the ISS.
  - schwabacher 15y ago
    Do you have any more info on the military shuttle replacement? That sounds like it could definitely provide some interesting reading
    - Joakal 15y ago
      https://secure.wikimedia.org/wikipedia/en/wiki/Military_space_shuttle https://secure.wikimedia.org/wikipedia/en/wiki/Military_spac...
      - schwabacher 15y ago
        Very cool, thanks!
bcl 15y ago
I love the last point. The shuttle's computer can only count to 365 days.
- cynest 15y ago
  And that it would take millions of dollars to fix.
- bigbento 15y ago
  I can empathize. I've always found date-related bugs to be the hardest to track down and messiest to resolve. Especially in applications consuming data from a huge variety of buggy input formats ("So it's a server in Australia, but their application layer adjusts time +36000 seconds and their durations are listed in days, but it's daylight savings here...") "Well, just don't fly the shuttle over New Year's" seems like a reasonable enough workaround for an otherwise highly planned out program, especially when, as a commenter in OP points out, the missions were only intended to run weeks at a time to begin with.
  - pavel_lishin 15y ago
    It's a good thing there were never any emergencies on the station near the end of December.
- thinkzig 15y ago
  Agreed. If that's not an example of YAGNI I don't know what is.
adrianwaj 15y ago
Is there need for an escape vehicle? Just tethering it to the ISS in case of an emergency could work. Who'd fly it down? Would it get damaged just sitting in space? How long can it be left powered down awaiting an emergency so it doesn't malfunction? How could it be accessed quickly in an emergency? How could it be disposed-of eventually? What's the likelihood of an emergency?
- Zak 15y ago
  The ISS keeps a Soyuz docked for use as an escape vehicle. It is very likely better suited to that purpose than a shuttle. See http://en.wikipedia.org/wiki/Soyuz_(spacecraft) http://en.wikipedia.org/wiki/Soyuz_(spacecraft)
  - burgerbrain 15y ago
    Exactly. The Shuttle is so incredibly ill-suited for that task that I'd wager the ISS would make a better escape vehicle from the Shuttle than the other way around. Soyuz crafts on the other hand are bloody brilliant at the job. Their modern reentry safety record is unparalleled.
    - adrianwaj 15y ago
      Have fun re-entering on the ISS http://en.wikipedia.org/wiki/Skylab#Re-entry http://en.wikipedia.org/wiki/Skylab#Re-entry
      - burgerbrain 15y ago
        That portion of my comment was very obviously tongue in cheek.
        bane 15y ago
        Welcome to HN, the "unfunniest place on the Internet".
Zak 15y ago
It's interesting to see all the anecdotes in the reddit discussion about the flight computer. It is variously claimed to be an 8086, to have less power that a pocket calculator or that it could be easily replaced with a more powerful modern computer. I'm puzzled by the fact that nobody in the thread fact-checked these claims. The shuttle's flight computers are, in fact five IBM AP-101s in a redundant configuration. See http://en.wikipedia.org/wiki/IBM_AP-101 http://en.wikipedia.org/wiki/IBM_AP-101
- aperiodic 15y ago
  People might have that misconception due to hearing about the Apollo flight and guidance computers, which were pretty janky. They had a really difficult to use interface, and used core-rope memory[1] that was woven together by old ladies. [1] http://en.wikipedia.org/wiki/Core_rope_memory http://en.wikipedia.org/wiki/Core_rope_memory
  - gaius 15y ago
    "Janky"? You're right, they should have used Ruby on Rails. And, ermm, AJAX 2.0. I'm sick of people slamming old tech with 50 years of hindsight. They were the smartest people in the world doing the best work they could with what they had available to them. And that's what they came up with - and it got the job done.
    - rwmj 15y ago
      And those IBM mainframes are massively more reliable than the crap (software and hardware) we use today.
  - nazgulnarsil 15y ago
    good lord the best part: "Some NASA programmers nicknamed the finished product LOL memory, for Little Old Lady memory." normally I don't post this sort of thing on HN, but LMFAO.
  - wazoox 15y ago
    > They had a really difficult to use interface AFAIK their Noun-Verb keyboard interface was deemed quite novel and particularly easy to use at the time.
JackWebbHeller 15y ago
> "The Shuttle suffers from its own Y2K problem"... "A software fix is possible, but it has never been worth the millions of dollars necessary to fix it." MILLIONS of dollars?!
- Klinky 15y ago
  Well, if it's a mission critical system with millions of lines of code that need inspecting by highly trained engineers, I don't think that's so far fetched. Some Y2K problems might require significant refactoring. Then pile on code auditing & certification before it can go back into production systems. There were some comments here just a few days ago about NASA software: http://news.ycombinator.com/item?id=2736107 http://news.ycombinator.com/item?id=2736107
- megablast 15y ago
  I imagine for something like the shuttle, there would need to be an awful lot of testing to ensure nothing goes wrong. If a lot of systems rely on the Date code, they all need to be tested.
- konstruktor 15y ago
  The software for the space shuttle flight computers is produced using an incredibly disciplined process. Here's a very idealistic article about it http://www.fastcompany.com/magazine/06/writestuff.html http://www.fastcompany.com/magazine/06/writestuff.html The downside is that every change is prohibitively expensive. I didn't bookmark the article but remember to have read that the astronauts are taught lots of rules like "if the computer displays x and y, this means that z", stuff that would usually be a simple software feature. The new year bug seems to be quite similar.
- ak217 15y ago
  Yes. But I'm not sure if I understand why they would need the flight control computers to stay on if it were to be permanently docked. Of the reasons he listed, only the obstruction of docking ports strikes me as valid. In any case, I think it would have been really cool if they spent a few millions to retrofit the shuttle into a last-chance emergency crew return vehicle (so enable avionics to survive an extended attachment to external power). Then a few years later, if it's not needed, have it land on autopilot in Mojave (or ditch into the Pacific if something goes wrong).
js2 15y ago
Another reason is power. Now, a couple of years ago, they added something called SSPS (Station to Shuttle Power System). This extended the docked capability of the shuttle, but it is by no means a permanent solution. It still uses a fuel cell to run some systems. Apparently, it's SSPTS[1] and it was never retrofitted to Atlantis: The SSPTS also aided Discovery’s twice extended STS-133 docked mission, although STS-135 will not be able to benefit from this system, given the SSPTS is not installed on Atlantis.[2] [1] http://en.wikipedia.org/wiki/Station_to_Shuttle_Power_System#Station_to_shuttle_power_transfer_system http://en.wikipedia.org/wiki/Station_to_Shuttle_Power_System... [2] http://www.nasaspaceflight.com/2011/05/sts-134-nasa-managers-reviewing-endeavours-tps-dings http://www.nasaspaceflight.com/2011/05/sts-134-nasa-managers...

151 points by soundsop 15y ago

noonespecial 15y ago

Last chance for the Americans to bring down any secret stuff that was on the station?

joeyh 15y ago
There does not seem to be any impediment to anyone of any nationality, including space tourists, visiting any part of the ISS, so color me doubtful on that theory. People do seem to avoid the cramped Russian side mostly, and who knows what goes on socially that NASA PR hides from us. Anyway, the US military has their own, apparently unmanned, shuttle replacement and do plenty of launches of secret stuff on conventional rockets. This is not surprising when you consider the relative budgets. Disposing of the station's trash seems a large enough logistical problem that getting one more shuttle-load out could be the real motivator. Sorta sad to think that the last shuttle will be essentially a garbage scow on landing. At least they didn't stuff it to the gills and send it down to burn up on reentry, like is done with the majority of craft that dock to the ISS.
- schwabacher 15y ago
  Do you have any more info on the military shuttle replacement? That sounds like it could definitely provide some interesting reading
  - Joakal 15y ago
    https://secure.wikimedia.org/wikipedia/en/wiki/Military_space_shuttle https://secure.wikimedia.org/wikipedia/en/wiki/Military_spac...
    - schwabacher 15y ago
      Very cool, thanks!

bcl 15y ago

I love the last point. The shuttle's computer can only count to 365 days.

cynest 15y ago
And that it would take millions of dollars to fix.
bigbento 15y ago
I can empathize. I've always found date-related bugs to be the hardest to track down and messiest to resolve. Especially in applications consuming data from a huge variety of buggy input formats ("So it's a server in Australia, but their application layer adjusts time +36000 seconds and their durations are listed in days, but it's daylight savings here...") "Well, just don't fly the shuttle over New Year's" seems like a reasonable enough workaround for an otherwise highly planned out program, especially when, as a commenter in OP points out, the missions were only intended to run weeks at a time to begin with.
- pavel_lishin 15y ago
  It's a good thing there were never any emergencies on the station near the end of December.
thinkzig 15y ago
Agreed. If that's not an example of YAGNI I don't know what is.

adrianwaj 15y ago

Is there need for an escape vehicle? Just tethering it to the ISS in case of an emergency could work. Who'd fly it down? Would it get damaged just sitting in space? How long can it be left powered down awaiting an emergency so it doesn't malfunction? How could it be accessed quickly in an emergency? How could it be disposed-of eventually? What's the likelihood of an emergency?

Zak 15y ago
The ISS keeps a Soyuz docked for use as an escape vehicle. It is very likely better suited to that purpose than a shuttle. See http://en.wikipedia.org/wiki/Soyuz_(spacecraft) http://en.wikipedia.org/wiki/Soyuz_(spacecraft)
- burgerbrain 15y ago
  Exactly. The Shuttle is so incredibly ill-suited for that task that I'd wager the ISS would make a better escape vehicle from the Shuttle than the other way around. Soyuz crafts on the other hand are bloody brilliant at the job. Their modern reentry safety record is unparalleled.
  - adrianwaj 15y ago
    Have fun re-entering on the ISS http://en.wikipedia.org/wiki/Skylab#Re-entry http://en.wikipedia.org/wiki/Skylab#Re-entry
    - burgerbrain 15y ago
      That portion of my comment was very obviously tongue in cheek.
      - bane 15y ago
        Welcome to HN, the "unfunniest place on the Internet".

Zak 15y ago

It's interesting to see all the anecdotes in the reddit discussion about the flight computer. It is variously claimed to be an 8086, to have less power that a pocket calculator or that it could be easily replaced with a more powerful modern computer. I'm puzzled by the fact that nobody in the thread fact-checked these claims. The shuttle's flight computers are, in fact five IBM AP-101s in a redundant configuration. See http://en.wikipedia.org/wiki/IBM_AP-101 http://en.wikipedia.org/wiki/IBM_AP-101

aperiodic 15y ago
People might have that misconception due to hearing about the Apollo flight and guidance computers, which were pretty janky. They had a really difficult to use interface, and used core-rope memory[1] that was woven together by old ladies. [1] http://en.wikipedia.org/wiki/Core_rope_memory http://en.wikipedia.org/wiki/Core_rope_memory
- gaius 15y ago
  "Janky"? You're right, they should have used Ruby on Rails. And, ermm, AJAX 2.0. I'm sick of people slamming old tech with 50 years of hindsight. They were the smartest people in the world doing the best work they could with what they had available to them. And that's what they came up with - and it got the job done.
  - rwmj 15y ago
    And those IBM mainframes are massively more reliable than the crap (software and hardware) we use today.
- nazgulnarsil 15y ago
  good lord the best part: "Some NASA programmers nicknamed the finished product LOL memory, for Little Old Lady memory." normally I don't post this sort of thing on HN, but LMFAO.
- wazoox 15y ago
  > They had a really difficult to use interface AFAIK their Noun-Verb keyboard interface was deemed quite novel and particularly easy to use at the time.

JackWebbHeller 15y ago

> "The Shuttle suffers from its own Y2K problem"... "A software fix is possible, but it has never been worth the millions of dollars necessary to fix it." MILLIONS of dollars?!

Klinky 15y ago
Well, if it's a mission critical system with millions of lines of code that need inspecting by highly trained engineers, I don't think that's so far fetched. Some Y2K problems might require significant refactoring. Then pile on code auditing & certification before it can go back into production systems. There were some comments here just a few days ago about NASA software: http://news.ycombinator.com/item?id=2736107 http://news.ycombinator.com/item?id=2736107
megablast 15y ago
I imagine for something like the shuttle, there would need to be an awful lot of testing to ensure nothing goes wrong. If a lot of systems rely on the Date code, they all need to be tested.
konstruktor 15y ago
The software for the space shuttle flight computers is produced using an incredibly disciplined process. Here's a very idealistic article about it http://www.fastcompany.com/magazine/06/writestuff.html http://www.fastcompany.com/magazine/06/writestuff.html The downside is that every change is prohibitively expensive. I didn't bookmark the article but remember to have read that the astronauts are taught lots of rules like "if the computer displays x and y, this means that z", stuff that would usually be a simple software feature. The new year bug seems to be quite similar.
ak217 15y ago
Yes. But I'm not sure if I understand why they would need the flight control computers to stay on if it were to be permanently docked. Of the reasons he listed, only the obstruction of docking ports strikes me as valid. In any case, I think it would have been really cool if they spent a few millions to retrofit the shuttle into a last-chance emergency crew return vehicle (so enable avionics to survive an extended attachment to external power). Then a few years later, if it's not needed, have it land on autopilot in Mojave (or ditch into the Pacific if something goes wrong).

js2 15y ago

Another reason is power. Now, a couple of years ago, they added something called SSPS (Station to Shuttle Power System). This extended the docked capability of the shuttle, but it is by no means a permanent solution. It still uses a fuel cell to run some systems. Apparently, it's SSPTS[1] and it was never retrofitted to Atlantis: The SSPTS also aided Discovery’s twice extended STS-133 docked mission, although STS-135 will not be able to benefit from this system, given the SSPTS is not installed on Atlantis.[2] [1] http://en.wikipedia.org/wiki/Station_to_Shuttle_Power_System#Station_to_shuttle_power_transfer_system http://en.wikipedia.org/wiki/Station_to_Shuttle_Power_System... [2] http://www.nasaspaceflight.com/2011/05/sts-134-nasa-managers-reviewing-endeavours-tps-dings http://www.nasaspaceflight.com/2011/05/sts-134-nasa-managers...