Update on ACS Operations
2 October 2006Hubble's workhorse, the Advanced Camera for Surveys (ACS), resumed science operations on 1 October 2006 with one of its three channels, the Wide Field Channel (WFC), brought back into service. Historically, this channel has accounted for 70-80% of all observations obtained with the ACS. Observations with the WFC form an integral part of the HST science observing plan for next week.
The ACS suspended operations on 23 September due to an anomalous voltage reading from the electronics box for the High Resolution Channel (HRC), one of its three cameras. The other two cameras are the Wide Field Channel (WFC) and the ultraviolet-sensitive Solar Blind Channel (SBC). The anomalous voltage reading in the HRC was caused by an open relay which normally supplies power to the HRC detector electronics. A brief on-orbit test Friday morning confirmed that this condition persists. Neither the WFC nor SBC is affected by this open relay, so operations with the WFC were cleared to resume as early as the observing schedule allowed.
Scientists and engineers from the HST Project at Goddard Space Flight Center, Ball Aerospace, and STScI are developing a plan for further tests of the HRC in the coming weeks to see if the HRC can be used in its present condition or whether the suspect relay needs to be exercised.