Tuesday, January 30, 2007

ACS on Hubble badly injured, may be dead?

A famous champion is badly injured on both sides and may need to be put down.

I'm not talking about Barbaro the racehorse, but about the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope. ACS suffered a (smoking) short circuit on Jan 27 that fried the Side B electronics.

Like other NASA instruments, ACS has redundant Side A and Side B electronics. ACS was using side B due to an earlier fault on Side A. Side B is now most probably dead. Side A may be usable, but probably only in limited modes that exclude the Wide Field Camera (WFC) responsible for the pretty pictures you've enjoyed from ACS & Hubble.

Of course, this happened the day after astronomers submitted 498 proposals to use ACS this year. Everyone's scrambling to rewrite, or create new proposals, now that ACS is dead or severely limited. I'm pondering writing a quickie Nicmos proposal -- it's an old instrument with a small field of view, and the observations wouldn't be very efficient -- but it may now be one of the better uses of HST.


Andrea said...

How repairable are either the Side A or Side B faults? I know the blown fuse would be replaceable if there's another servicing mission, but I also know that just replacing a fuse without fixing what made it blow is not a recommended electronics technique.

astrodyke said...

HST's website says astronaut repair is being discussed. But servicing mission 4 is already chock full: replace COSTAR with COS, replace WPFC2 with WFPC3, and attempt to fix STIS.

Worse, what are the odds that the short circuit, if locatable, is astronaut- servicible? Unless it is, then you're exactly right -- swapping fuses doesn't help.

L. Riofrio said...

HST service mission, last launch for Atlantis is scheduled for September 11, 2008.

You might enjoy the Beyond Einstein Town Hall meeting in Newport Beach Thursday. That Fry's store in Burbank is a wonder too. Great posts, want to trade links?

Jackie M. said...

A little bird told me that Ed was busy regaling everybody with last-minute proposal stories at Monday morning coffee when Rodger walked in the news.

After a moment of silence, Ed suggested that killing the messenger might be the only alternative left.