NASA announces major delay in Hubble repair mission

By William Atkins
Tuesday, 30 September 2008 18:54

Science - Space

The Hubble Space Telescope had a glitch in one of its control systems and turned itself off. Luckily, this happened before the HST repair mission STS-125 got off the ground. NASA is now attempting to fix Hubble from the ground, and possibly replace the faulty system in space, but not until 2009.


The significant "Hubble Anomaly," as it is being called by NASA, occurred on Saturday, September 27, 2008, when a channel on “side A” of a data formatting computer, called the Hubble Control Unit/Science Data Formatter (CU/SDF), failed.

Hubble uses a Science Instrument Control and Data Handling (SICDH) unit to control numerous instruments, to receive commands from ground controllers, and to send data and images back to Earth.

The SICDH uses the CU/SDF to store and transmit science data from the telescope's five main instruments and format it into data packets for transmission.

However, on Saturday, the CU/SDF went into “safe mode” after failing in order to protect itself from further damage.

The back-up channel (“Side B,” or CU/SDF-B) is expected to be turned on later to restore usage to the telescope.

However, Side B has never been turned on before in space. Ground controllers are optimistic and hopeful that Side B will be able to replace the failed channel.

According to NASASpaceFlight.com, “Side B side has not been operated on orbit, for HST’s entire on orbit service life it has operated on Side A (CU/SDF-A). However, the B side was fully tested before launch.” [NASASpaceFlight.com: “Hubble control system failure - STS-125 launch date delayed”]

Page two continues the story.