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Programming IT Technology

Open Source Satellite Control 90

Debra writes "Have you ever wondered how you harness a satellite control system written in three languages, on four development platforms, and deployed to multiple client environments? With open source, naturally. When one wrong move can cost millions, you must rely on teamwork, smart design, and open standards to keep the project -- if not the satellite -- from going down in flames. This article covers software engineering basics, taking advantage of outside solutions, and scripting multi-million-dollar manuvers."
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Open Source Satellite Control

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  • Reliability? (Score:4, Insightful)

    by delta407 ( 518868 ) <> on Friday September 06, 2002 @10:17PM (#4210699) Homepage
    Open source software is plenty stable -- when it's mature. But, when "one wrong move can cost you millions", can you afford a kernel oops because someone forgot a \n?

    See, in this case, the nice part about commercial software is that you have someone to blame, and you at least stand a chance in court (IANAL, but it would be under contract law), so you have an opportunity to recoup your losses. In this case, an "oh yeah, fixed in CVS" isn't good enough.
    • See, in this case, the nice part about commercial software is that you have someone to blame, and you at least stand a chance in court (IANAL, but it would be under contract law), so you have an opportunity to recoup your losses.

      When was the last time you heard of NASA suing someone successfully to recoup losses due to contractor/vendor negligence?

    • Nobody EVER gets any money from software vendors in lawsuits, contract or EULA. By spreading that myth, you perpetuate the "stupid consumer" model of software.

      I don't know how you grew up, but I've always been taught "Buyer beware" is the the best model, and the most aware buyer is one who can intelligently check out the product he/she is buying.

      If I was paying somebody for a service, I'd want to at least be able to satisfy my own curiosity about how well it works, at least so that I'll sign off on the check. I would want to know, ESPECIALLY if it was controlling my precious satelite.

      In fact, I'd BET that for commercial satelites, the people funding any launch have teams of outsiders checking the code.

      I could also imagine that at NASA, there is a mixture of vendor written and in-house written.

      But don't fall for the "who ya gonna sue" stupidity......there's nobody, they're already gone.
    • But, when "one wrong move can cost you millions", can you afford a kernel oops because someone forgot a \n?

      Like Microsoft "We don't know why all Windows boxes are being hacked" has never had one-off and buffer overflow problems?? A proprietary programmer is no more infallible than an OS one. The big difference with OS is that if the software blows up, you don't have to wait on the pleasure of your supplier to get it fixed.

      With Open Source, you can also check the source code yourself and make sure that the really critical stuff isn't missing a \n in a critical place.

      Open source doesn't make software perfect -- It just makes it easier to fix.

    • See, in this case, the nice part about commercial software is that you have someone to blame, and you at least stand a chance in court...

      If that was true, Microsoft would be bankrupt by now...
  • But what if... (Score:1, Offtopic)

    by MBCook ( 132727 )
    • ... I want my satalite to go down in flames?
    • ... I want to have to hard reboot it every 10 days even though missions must be planned 6 months in advance?
    • ... I don't WANT other people to be able to use the software. As one of my professors says: "Job security!"
    • ... I planned to write a bunch of these and am now drawing a blank?
    • ... I regret posting this because I'm a karma whore and it gets modded down?
    • ... this post is completely off topic by now?
  • You know... It's too easy to be famous these days... just start any weird project and put an "Open Source" and "Linux Compatible" or "Microsoft Free" on it.

    You mean... Open Source controlled satelites? What is next? Open Source ARM-Controlled inflatable dolls?
  • We all know that Windows was "found" in the startwars sattelite system after a "memory protection fault" required astranauts, including Bill G., had to fly to orbit to reboot it.

    What only I know is that Windows crashes for a purpose. That purpose is to sell upgrades. Consumers are conned into believing this "progress". NASA has been conned into thinking that this ISN'T "extortion" or "blackmail".
  • by Anonymous Coward on Friday September 06, 2002 @10:32PM (#4210754)
    Did I see a Windows screenshot? Fer crissakes, people. If you want a decent satellite ops program, use OASIS []. CCSDS compliant, multi-mission, multi-terminal, UN*X-based... None of this Java and Windows namby-pamby ops software. Yeesh.
  • by Waffle Iron ( 339739 ) on Friday September 06, 2002 @10:51PM (#4210794)
    I highly recommend the excellent and Free (as in love) GNU metric2imperial library if you are planning something ambitious like a Mars mission. It can really reduce the possiblity of a miscommunication with your subcontractors.


    met2imp --len=fathoms --vol=pecks --mass=apothecary_oz < >
    • by Anonymous Coward
      Waffle Iron is trolling. The imerialmetric problem that NASA had with it's subcontractors wasn't an oh, they meant meters, not yards. Oops...

      The problem was that the measurements drifted average hundres of conversations between two systems. The Free (as in love) GNU metric2imperial application introduces exactly those types of errors.

      The best solution is just to just pick a system so that these conversion errors aren't introduced!
  • ... I wonder if the developers fought over which scripting language to use for those million-dollar manuevers, PERL or Python?
    • Re:Scripting Wars (Score:1, Informative)

      by Anonymous Coward
      Both are in use in different parts of at least one satellite control system I am all too familiar with. Python is doing some telemetry crunching while perl is used extensively for ground control command scripting.
  • by Anonymous Coward
    why not just use Windows ME? It'll work.... hehehe, bastards.
  • Speaking of the benefits of Open Source for high-risk missions, perhaps that Mars probe [] would have fared better if only management had chosen to use Perl with the freely available Math::Units module!
  • That article seems to cover usage of open-source software being used by a structured team.

    I think the /. audience has always pulled for is open-structure teams, i.e. a thousand geeks looking at code and output to find flaws.

    I know I for one am geeky enough to sit and stare for hours at sat telemetry and uplink commands for weird anomolies...nothing more exciting.

    Amateur radio sats have been leaning that way, I hope someone gets around to it.

    -Dan N7NMD/9W2DU
  • I really believe this is a great idea.

    I would love to see big, important, public projects utilizing open source.
  • by ghostlibrary ( 450718 ) on Friday September 06, 2002 @11:51PM (#4210953) Homepage Journal
    Actually, NASA satellite ops often uses generalized environments (was it called MOPS?) and mix contractor-produced customerware with in-house software or scripting. Then, use Perl to create stuff after launch that was needed, or to make stuff web-accessible (internal network only, sorry).

    Perl and Tcl/Tk are still popular (Tk for GUIs, Tcl or Perl for scripting).

    It's not GPLed open source but, within NASA, it is open source.

    Many missions are trying to move away from the 'custom designed only-works-for-us' software because it becomes rapidly dated.
    • It's not GPLed open source but, within NASA, it is open source.
      I guess it's JPL []ed.
  • Good thing its a nice buzzword too or IBM wouldn't have bothered with this story in the first place.

    They could've made it a little less obviously a commercial though. Seriously, "Migrate your VisualCafé applications to WebSphere Studio by following this three-part series of articles:"?

  • Last time i checked maneuver was spelled maneuver, not manuver.

    I suppose this is how open source should behave... Working our way to an error free slashdot! ;)
  • "When one wrong move can cost millions, you must rely on teamwork, smart design, and open standards to keep the project -- if not the satellite -- from going down in flames"

    You should consider a career as a preacher.

  • Beeing involved with TT&C I can tell you it is quite hard to loose a satellite once it is in position. Besides having a lot of redundancy and beeing fool proof in case something very wrong happends and he is about to crash into atmoshphere he will manouver itself out and place itself in a high orbit waiting slot. There is a funny storry about Telespazio Italia "loosing" a satellite. It was a scientific satelite. Periodicaly you had do do checks and orbit corections but when the checks were scheduled there was a technical problem and the guys that were supposed to fix it (the shift) were sleeping. As a consequence the satellite did get the telemetry controls at the right time and in 2 hours thought something verry wrong is happening and flew away in a safe position. It took them 4 months to get it back where it was supposed to be and shorten its life a lot doe to fuel consumtions. As for the software it was just about the time because 90% of the comercial and verry expensive software is full of crap.
  • From the article:
    Only last-minute heroism and a remarkably potent design were able to rescue the operators' displays from severe delays.
    Um, if you need your last-minute heroism... it wasn't a remarkably potent design, now was it?
  • I know it's a bit off topic, but not too much so. The only thing that has kept me from buying a DirectPC set is that I would have to buy a new MS XP system to act a a gateway. Talk about security issues. Anyone know if it will run in a XP VM under Linux? Firewall issues? Matti
  • This says it all. (Score:3, Interesting)

    by FreeLinux ( 555387 ) on Saturday September 07, 2002 @10:53AM (#4212096)
    Inadequate JVMs forced migration to Windows NT,

    Not a particularly strong endorsement of open souce now, is it? I'm sure we'll see this used in MS literature describing the stability of MS products. Something like:

    NT/2000/XP - So reliable, that the JPL uses it to control their satellites.
  • It's not just the government funded agencies or commercial satellite companies that use command and control systems. There are many amateur high altitude ballonists that need a way to send commands and receive data from payloads attached to balloons. Here in Colorado, Edge of Space Sciences [] is a group of enthusiasts that launch and recover high altitude balloons with a variety of payloads. They are always looking for volunteers to help with launch and recovery. There are similar groups thoughout the U.S.
  • Some data about FedSat [], a Scientific R&D microsatellite that's due for launch on the next H-2A from Tanegashima:

    Firstly, the on-board software is in Ada-95, using the 3.13p version of GNAT [] as the compiler and RTEMS [] as the Run-time Kernel. Both Open-Source, and the 'p' in "3.13p" means public, free-as-in-beer. The on-board software was developed mostly by Software Improvements [], a bunch of software professionals who are heavily into SLCMs, CMM, etc. And lo, it worketh, on-time, under-budget.

    The ground station is another matter. OASIS [] was tried, but couldn't do all that was required. In a spectacular case of less-than-wonderful-judgement, VB on Windows was used for development. After a while, they got some software pros to work on that one too, rather than the hack'n'slash electronics engineers. Well, it partially works - enough so that a few months or years after launch, it will do most of what's wanted.

    Moral: if it's important, and has to work first time, every time, do it in Ada and open source, and use the principles described in the parent article. If it's not so important, and can be fixed up afterwards, you're still better off using Ada, though Java's a good second choice. The only reason Ada's so good is that it makes it easy to adhere to good software engineering principles, such as teamwork, smart design, and open standards.

    • Separate Public view and private view -> Interfaces between teams made easier
    • High-level (generics, tasks etc) and low-level (address clauses) features ease design task
    • Standardised - Ada-83 was standardised as Mil-Std-1815A in January 1983 and later as ISO/IEC 8652:1987, Ada-95 as ISO/IEC 8652:1995.Copies of the LRM (Language Reference Manual) [], style manual etc are all freely available on the web.

    A.Brain, Rocket Scientist []

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