In January 2007, Hubble’s Advanced Camera for Surveys (ACS), the instrument responsible for many of Hubble’s most impressive images of deep space, stopped working due to an electrical short.
In February the portion of Hubble’s Advanced Camera for Surveys (ACS) used to study auroras and weather on solar system planets was restored, but the rest of the camera remains out of commission.
ACS has three cameras, or channels. The solar blind channel, now returned to life, uses a photon-counting detector to study objects visible only in ultra-violet light. For instance, it was used to study Jupiter’s auroras.
The wide-field channel, known for its efficient collection of light and surveys of the universe, and the high-resolution channel, capable of taking extremely detailed pictures of astronomical objects, are not functioning, but engineers are still studying whether the two channels could be revived during the upcoming servicing mission to Hubble in 2008.
Hubble still has other significant science capabilities. The Near Infrared Camera and Multi-Object Spectrograph (NICMOS), the Wide Field Planetary Camera 2 (WFPC2), and the Fine Guidance Sensors (FGS) are all working. ACS was installed in 2002 and has essentially met its expected lifespan of five years.
Observations that had been scheduled for the still-working instruments will be moved, when possible, into the time slots left empty by ACS’s breakdown. Current ACS programs were reviewed to determine which observations might be transferred to other instruments -- most likely WFPC2.
In 2008, astronauts will install a new instrument, called Wide Field Camera 3 (WFC3), in Hubble. WFC3 will replace and improve upon many of the capabilities lost with the partial injury to ACS.