Hubble fix hits snag, is delayed

By Phil Plait | October 17, 2008 12:10 pm

I just heard that something has gone awry with the switching on of the backup system on Hubble. It’s not clear what’s going on as I write this or how serious it is, but Hubble has gone back into "safe mode" which is when it shuts itself down and awaits new orders. NASA is planning a telecon on this at 3:00 Eastern time. I unfortunately won’t be around to listen, but it will be webcast on their site.

I’ll post more info as I find it.


Comments (19)

  1. But everything was going along so well. B-side telemetry looked good. Maybe it’s thermal issue – these usually kicks in after a delay.

  2. ‘scuse my grammar. publik skool lernt me well.

  3. This is an instance where I sincerely wish we could all mentally influence Hubble with our well wishes and thoughts to fix itself.

    Hmmm, has NASA considered putting some psychics on the spot? If they are so confident in their abilities, they should have everything fixed in a jiffy.

  4. skepTick: I wondered about thermal issues as well… let’s hope for the best here!

  5. It’s a shame kicking it isn’t an option from 600 miles away.

  6. almurray1958

    webcast delayed until 16:00 EDT

  7. Todd W.

    It’s Mercury’s fault, clearly.

  8. I think McCain is behind this. He thinks the Hubble is a kaleidoscope.

  9. Back to ‘safe mode’?
    the F8 key is stuck!



  10. Phil (et al.): The HST486 (replacement to the DF-224) computer that manages the spacecraft pointing control and other subsystem tasks safed, as it is supposed to do, the NSSC-1 (NASA Standard Spacecraft Computer 1) that normally interfaces with the science instruments, and then the SI’s themselves at 21:14 UT. The two computers “talk” to each other across what is known as a “Processor Interface Table”, or PIT. A continual “handshake” (PIT toggle) between the two computers is expected. If the DF-224 does not get that handshake it presumes the NSSC-1 may have a problem and, through a predefined sequence of inter-computer commands puts the NSSC-1, and then seperately the HST Instruments into a “safe” configuration. Of course, then, the “stored command plan”, which was on a path for recovery to restart science, carried out by the NSSC-1, is suspended.

    What caused the loss of the PIT toggle? That is still under investigation. But, what is known is that the redundant “Command Unit/Science Data Formatter B”, part of the Command and Data Handling (C&DH) unit side A, that failed after 18 years is apparently fine. In fact, the NSSC-1 memory after it was safed was successfully dumped to the ground through CU/SDF-B. A preliminary analysis of that memory dump points to a “potential problem” (emphasis is on potential, as this is quite early in the investigation) in the Central Processor Module (CPM) on C&DH Side B. But unclear if that is a potential H/W, configuration (remember everything was just switched over to Side B with a lot of reconfiguring), or S/W “problem” – so I would not jump to any conclusions ahead of the good folks at Goddard looking at this carefully and methodically.

    In the short term… As the CPM is redundant – AND can be cross-strapped- (in a
    side A/B hybrid configuration) by ground command, Goddard is in the process of moving contingency operating procedures to affect that cross-strap using the high-fidelity Hubble simulator (the VEST “Vehicle Electrical and Test” facility). That may already have been done as I write this, and thus (presuming that ground test is succesful, as I would expect it to be), the COP would be available to do the same on-orbit if further diagnostics and analysis indicate a side A/B hybrid would (for now) take care of the problem.

    The above is an “unofficial” explanitory status. Look to NASA for the official word.

    Glenn Schneider

  11. Thanks 10^6 Glenn!
    The show is underway… Typing & listening…

  12. Charles Boyer

    Glenn: superb explanation–deep yet not overwhelmingly technical.

    Bottom line is that Hubble needs some TLC from some astronauts. We’re very lucky that these problems didn’t break out after the orbiter had come and gone, because another repair mission would have been all but impossible from a political standpoint.

  13. Cheyenne

    It’s very cool to see how these articles can evolve with some of the comments. Awesome Glenn.

    Although I clearly have no real understanding of the computer equipment on Hubble, it’s nice to hear from somebody that does, and seems to think that NASA can fix it.

  14. Thanks Glenn! For everyone’s info, Glenn is an old friend, and we worked together on a few Hubble observations led by him. He knows his stuff!

  15. IVAN3MAN

    Yes, just click on his name and you’ll see for yourself. His C.V. is impressive!

  16. Did anyone consider that the problem might be condensation? You know, it’s really cold at those altitudes and if there’s any humidity in the atmosphere….oh wait.


  17. Joker

    William won my best post of the thread & day award on October 17th, 2008 at 1:31 pm with :

    “I think McCain is behind this. He thinks the Hubble is a kaleidoscope.”

    Classic. ūüėÄ

    ROTFLMAO! 8)

    Mercury to blame? Well if its a thermal issue then * the mercury * (hg) is a bit of an issue .. ūüėČ

    NB. Hg = Mercury as in Na =Sodium & Cl =Chlorine & Au = Gold.


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