Hubble Advanced Camera Broke

Ok, it is really official Space Telescope news on ACS (dynamic web page)

Spare power electronics popped, not recoverable, may not be repairable.
They're looking to see if they can run the ACS SBC only off the A-side electronics (which failed last year, which is why the ACS is running on the spare).

also on NASAwatch

This is bad. Could really muck up the current jobs round, ACS must fund 1-200 postdocs.
If they can switch to A-side, it sounds like only the Solar Blind Channel (narrow field ultra-violet imaging) can be used, not the optical wide field or high resolution cameras.
Argh.

Full text below:

29th Jan 2007 - 6pm or so.

HST Mission Update

Update on HST Safing Status
HST entered an inertial hold safemode on Saturday morning, Jan. 27. The safemode entry was tripped off by the detection of a pressure increase in the Aft Shroud of the telescope, the large cylinder that holds the scientific instruments. At the same time, there was clearly a power anomaly in the ACS (Advanced Camera for Surveys). Data from the time of the incident have been recovered from the data recorders (HST was out of contact with the ground when the event occured) and have been quickly analyzed.

Unfortunately, it is apparent that there has been a serious failure in side 2 of the ACS. ACS has two redundant chains of electronics, side 1 and side 2. Side 2 electronics have been in use since June 2006. Indications are that there was an electrical short circuit of sufficient duration and intensity to blow the fuse on side 2. The short circuit had sufficient energy that it resulted in a short release of gaseous material, which tripped the pressure sensor alarm. An Anomaly Review Board (ARB) will attempt to identify the precise cause of the problem, but it is very unlikely that we will be able to use ACS side 2 again. The ARB will have to establish whether it is safe to return ACS to side 1 operation. If so, we will be able to use the SBC, but not the HRC or WFC. The ARB will also help establish whether there is any prospect for servicing the ACS. While the blown fuse can easily be replaced by an astronaut, repairing or working around the short circuit could be considerably more difficult.

The NCS (NICMOS Cooling System) was also safed during the event, as an automatic reaction to the detection of higher than normal pressures in the aft shroud. Subsequent analysis of the engineering data shows no sign of any problems with the NCS or the NICMOS. The NCS will be restarted on Monday afternoon, and should restore the NICMOS to proper operating temperature in a day or two.

The apparent loss of the ACS is obviously a serious blow to the HST science program. ACS observations have dominated our observing schedules since its installation during SM3B. We now have the problem of replacing the ACS portion of the observing program and continuing with the best possible science program with the telescope, at least until SM4. Several steps are being taken in this regard. First, the schedulers will be doing the best they can to move up available Cycle 15 NICMOS, WFPC2, and FGS observations. Second, we will activate the ACS Contingency programs that have been proposed and selected for just this situation. Contact Scientists and Program Coordinators will be working with the PIs of these programs to get them available and into the scheduling system as soon as possible. As was done with STIS, we will review all the current ACS programs and determine which might be transfered to other instruments, most likely WFPC2, in a way that maintains the scientific intent of the program. Finally, we are considering extending the Cycle 16 Phase I proposal deadline, which was last Friday, in order to give the astronomy community a quick opportunity to switch proposals from the ACS, and to provide additional NICMOS, WFPC2, and FGS proposals for the TAC to review. Notification of such an extension will come from SMO.