HST data recorder failure October 7, 2008Posted by aquillam in Astronomy.
Tags: HST, instrumentation, space missions
I just had a telecon sponsored by the Education Office at GSFC about HST, so I want to get this info written down before I get confused.
If you pay any attention to astronomy news, you’ve heard something is wrong with Hubble. Side A of the Control Unit/Science Data Handler (CUSDF) failed about a week ago, just in time to stop the servicing mission (seriously. The team was on its way to Huston for the final testing and training when they got the phone call to turn around and come home). The CUSDF is part of the Science Instrument Command and Data Handler (SIC&DH). The SIC&DH takes commands from the computer and interprets them for the instruments. It also takes the data from the instruments and formats it into a standard format that can be transmitted back to Earth and interpreted easily. Without it, no data comes from the science instruments.
The HST Program hired a independant group to do testing on the ground unit this past week. That team decided there was very little risk in using the B side of the CUSDF, so on the 15th ground controllers will begin the switch over. It should take about a day and a half of sending commands back and forth to get Hubble talking to us again. HOWEVER, the B side is the back-up, so if we do nothing else and the B side fails, that would end the mission.
Since we really aren’t ready to end the mission yet, the HST program intends to swap out the current SIC&DH with the one that’s been in storage on the ground for the past 18 years. It was tested yesterday and is working nominally. They could just change out the CUSDF, but it is actually harder to swap out just that componant, and of course the other instruments could fail, and they’d just have to replace the whole thing latter anyway. The new CUSDF will be programmed to use side B, with side A as backup so that no reprogramming is needed to switch the the new module.
The Office of Human Space Flight runs the shuttle program. They want the launch pad back for Endevor’s mission, so the payload from Altantis will be moved to the very clean and spacious Payload Hazardous Systems Facilty until the new SIC&DH can be confirmed to be flight ready and loaded into the payload (and no, the payload isn’t hazardous, that is just the most convenient facility). If all goes well, the mission should launch mid February, with May as the backup date. It should still launch on Atlantis. While this will add some time to the time astronauts have to spend working on Hubble, it should not add any time to the down-time for the telescope.
Some other info on this mission:
This is currently the last planned servicing mission (write your congressman and tell him/her how much you want Hubble to continue!)
Part of the mission is to install a new camera to replace the Advanced Camera for Surveys that failed a while ago, and a new spectograph. Currently, Hubble can see light between 400 – 900 nm with the WFPC. The new instruments will expand its view to 200 – 1700 nm, or near infra-red to near ultra-violet light.
The new instrument adds about 200 lbs to the mission
The mission has the heaviest mid-deck payload ever.
HST is still sending engeneering data, and it can send astrometric data back with that.
Mission Specialist (astronaut) Andrew J. Feustel is planned as the speaker for the 2009 Astronomy at the Beach in Kensinton Metropark, Milford MI, Sept 25 & 26, 2009.