http://www.stsci.edu/hst/acs/sm4/requirements/localNews?display_type=all http://www.stsci.edu/hst/acs/sm4/requirements/localNews?display_type=all#HeadlineNews The launch of the Hubble Space Telescope Servicing Mission 4, planned for October 14, 2008, has been delayed. Due to a Hubble Space Telescope malfunction that occurred on Saturday, September 27, 2008, affecting the storage and transmittal of science data to Earth, NASA will evaluate the investigation results before fully determining the impact to the launch of STS-125 for the HST Servicing Mission 4.<br /> <br /> Under consideration is the possibility of flying a back-up replacement system as part of the payload, which could be installed during the servicing mission. The back-up unit will need to be checked out and tested at Goddard Spaceflight Center and as a result, won&#8217;t be ready to be delivered to Kennedy Space Center in Florida until the first week in January 2009. NASA now will fly space shuttle Endeavour's STS-126 mission to the International Space Station first, with the STS-125 servicing mission moving into 2009. Endeavour is targeted to launch in mid-November 2008. <br /> <br /> The malfunctioning system is Hubble's Control Unit/Science Data Formatter - Side A. Shortly after 8 p.m. on Saturday, September 27, the telescope's spacecraft computer issued commands to safe the payload computer and science instruments when errors were detected within the Science Data Formatter. An attempt to reset the formatter and obtain a dump of the payload computer&#8217;s memory was unsuccessful. <br /> <br /> Additional testing demonstrates that Side A no longer supports the transfer of science data to the ground. A transition to the redundant Side B should restore full functionality to the science instruments and operations.<br /> <br /> The transition to Side B operations is complex. It requires that several other modules used in managing data also be switched to their B-side systems. The B-sides of these modules last were activated during ground tests in the late 1980&#8217;s and/or early 1990, prior to the launch of Hubble.<br /> <br /> The Hubble operations team has begun work on the Side B transition. The transition may occur around October 17 to 22, after the team completes its work and undergoes a readiness review.<br /> <br /> Hubble is expected to return to science operations soon after the transition to Side B, if the reconfiguration is successful.