The backup computer that helps operate ISS’s robot arms is not responding to commands.

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The backup computer that helps operate ISS’s robot arms is not responding to commands.

The timing could not be worse.. Though the number one computer is functioning fine, this unit is essential for controlling the robot arm that will berth Dragon to ISS this week.

Side note: The article above described this problem in its headlines as a “glitch.” I despise this word, as it is generally used by government bureaucrats to minimize the seriousness of a failure. The Soviet era bureaucrats in Russia loved it. I have noticed it popping up in American news reports relating to space more and more, and it is never a very accurate description of the situation. This computer failure is not a “glitch,” it is a serious failure of an essential piece of hardware.

Update: Because a spacewalk will be required to fix the backup computer, NASA has okayed the launch of Dragon. They need it to arrive first because it carries a new spacesuit and other parts needed to replace the suit that almost drowned an astronaut during a spacewalk last summer.

Note: I was in the back country of Arizona this past weekend, caving, which is why I am only now getting up to speed on this weekend’s news.



  • mpthompson

    I agree with you regarding the word “glitch”. Rarely is a glitch ever a “glitch”. Seems the word was used extensively in the media recently to describe the Obamacare web site as well.

    I’m curious as to the nature of the computer controlling the arm on the ISS. I presume it’s a embedded system of some kind that really needs to be close proximity to the physical arm. On one hand this is understandable, but on the other hand it seems to me that extraordinary efforts should be made to try and place such equipment in locations that don’t actually require a spacewalk for access. I guess I’m being to optimistic that such critical computer systems can be made accessible in such a way on the ISS.

  • Stu Harris

    Agree about “glitch.” A related non-word is “typo”, now used for any small text error. Its original meaning, of course, is an error that it not the author’s fault because it was made by a typographer. These days authors are their own typographers, so a “typo” is just an “error”.

    I’ve seen it used for errors that go beyond mere spelling mistakes, too. When Mike Bara wrote “An annular eclipse means that the Moon and Sun are in perfect alignment, but the Sun is not totally blotted out because the Moon is a little too close to the Earth…” (‘The Choice’, p.214) he excused himself by claiming it was a mere “typo.”

  • Kelly Starks

    Great so a critical system to “berth” Dragon, may be failing, and can’t be fixed if it fails without equipment to be carried by Dragon.

    The universe has a nasty sense of irony.

  • Edward

    This morning on the radio, I heard the Heartbleed problem referred to as a major glitch. I, too, considered a glitch as a small, temporary problem, but describes it as any problem in a machine or program:
    1. a defect or malfunction in a machine or plan.
    2. Computers. any error, malfunction, or problem.

    Definition 3 may be where we got the idea that a glitch was a relatively minor thing. “a brief or sudden interruption or surge in voltage in an electric circuit.”

  • Pzatchok

    So does NASA giving the go ahead for the launch mean that Dragon can dock on its own?
    I can’t see how Dragon is so far behind the Russians craft in terms of tech that it can’t dock on its own and the Russians can. Well the Russians at least don’t need the arm to dock.

    Or does it mean they will be able to use the arm?
    Are they that sure that their repair effort will work?

    Or are they just going to leave the cargo ship hanging out there until the Russians lift more replacement equipment up for us.

  • You need to understand the engineering designs here to understand what is going on.

    1. Dragon is not designed to do a docking. It doesn’t have the right kind of equipment to do the maneuver all by itself. It can rendezvous with the station however with great accuracy.

    2. The backup computer that has failed specifically controls the position of the robot arm on the truss, as does the primary computer that still works. Neither controls the arm itself or how it moves to grab things.

    3. The berthing itself is done manually by an astronaut inside the station, operating the robot arm.

    What they have done is to use the primary computer for sliding the robot arm along the truss to immediately move the arm to the correct position so that it can be operated by the astronauts to berth Dragon. With this done, the failure of the back-up computer is less critical, at least for the moment.

    Dragon will arrive, as is normal, and astronauts will use the robot arm to grab and berth it, as is normal. It will not hang there in space.

  • Kelly Starks

    Could be embarrassing if they have to go out a hatch and lasso it and drag it in. ;)

    Dragon wranglers. ;)

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