Hubble Problems

18 10 2008

Engineers at the Goddard Space Flight Center in Maryland have hit two
new snags in their effort to repair the Hubble Space Telescope after a
major equipment failure in space last month.

This problem began September 27 with the failure of Hubble’s Science
Instrument Control and Data Handling (SIC&DH) system. The on-board
computer coordinates commands to the satellite’s various instruments
and then downlinks the scientific data to the ground. While that
computer is down, most science observations are at a standstill.

The system was built with a fully redundant backup channel called “Side
B,” designed to come online in the event “Side A” ever failed. Hubble
team members at Goddard began a complicated process on Wednesday to
send computer commands to the telescope to switch over to Side B, and
hoped to have everything completed by midday Friday.

More problems began to pile up…

Early in the afternoon, there were problems powering up one of Hubble’s
instruments, the Advanced Camera for Surveys, though other instruments
turned on normally.

Later in the evening, a communications failure between multiple onboard
computers put all the science instruments, including the main science
computer, into safe mode. It is unclear how these problems are related
to each other or the activation of the SIC&DH Side B channel.

Even if the switch over to the Side B backup ultimately fails, Hubble
managers say the design team had the foresight 20 years ago to build a
spare SIC&DH system, which has been warehoused at Goddard all this
time while the original instrument perked along just fine.

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Hubble’s Communications Fail

30 09 2008

NASA said Monday that it is delaying its mission to the Hubble Space Telescope until next year because of a serious breakdown of the observatory in orbit.

The Atlantis team was scheduled to blast off October 14 to make other repairs and upgrades on the Hubble.

Space shuttle Atlantis had been scheduled to blast off in just two weeks, but an unexpected problem with the Hubble appeared Saturday night, when the telescope stopped sending science data.

That potentially means a new repair issue for the astronauts to confront, one they haven’t trained for and never anticipated.

The failure of the command and data-handling system for Hubble’s science instruments means the telescope is unable to capture and beam down the data needed to produce its stunning deep space images.

Early Monday afternoon, NASA announced that the October 14 launch had been postponed until at least early next year, possibly February.

When Atlantis does fly, NASA may send up a replacement part for the failed component.

It would take time to test and qualify the old replacement part and train the astronauts to install it in the telescope, NASA spokesman Michael Curie said. NASA also would have to work out new mission details for the astronauts who have trained for two years to carry out five Hubble repair spacewalks.

“The teams are always looking at contingencies, and this is just something that has cropped up we have the ability to deal with. They’re just trying to decide what direction we want to go,” Curie said.

There is a backup channel for the science instruments’ command and data-handling system, and NASA may be able to activate it successfully so that data transmission resumes, Curie said. But if NASA relies solely on the backup channel, there would be no other options if it malfunctioned.

Work has begun to switch the telescope to the backup channel. It is a complicated process; the backup channels on the various modules that must be switched over have not been turned on since the late 1980s or early 1990, right before Hubble was launched. The Hubble team hopes to complete the job by the end of the week.

Curie stressed that the telescope is not in trouble; it just cannot send science information to ground controllers. That means NASA is unable to receive the dramatic pictures Hubble is known for.

The mission by Atlantis and a seven-person crew will be the fifth and final servicing mission to Hubble.

Now, Endeavour will be the next shuttle up, on a trip to the international space station in November. Endeavour is at the launch pad; it was supposed to serve as a rescue ship for Atlantis in case of trouble.





Hubble’s Communications Fail

30 09 2008

NASA said Monday that it is delaying its mission to the Hubble Space Telescope until next year because of a serious breakdown of the observatory in orbit.

The Atlantis team was scheduled to blast off October 14 to make other repairs and upgrades on the Hubble.

Space shuttle Atlantis had been scheduled to blast off in just two weeks, but an unexpected problem with the Hubble appeared Saturday night, when the telescope stopped sending science data.

That potentially means a new repair issue for the astronauts to confront, one they haven’t trained for and never anticipated.

The failure of the command and data-handling system for Hubble’s science instruments means the telescope is unable to capture and beam down the data needed to produce its stunning deep space images.

Early Monday afternoon, NASA announced that the October 14 launch had been postponed until at least early next year, possibly February.

When Atlantis does fly, NASA may send up a replacement part for the failed component.

It would take time to test and qualify the old replacement part and train the astronauts to install it in the telescope, NASA spokesman Michael Curie said. NASA also would have to work out new mission details for the astronauts who have trained for two years to carry out five Hubble repair spacewalks.

“The teams are always looking at contingencies, and this is just something that has cropped up we have the ability to deal with. They’re just trying to decide what direction we want to go,” Curie said.

There is a backup channel for the science instruments’ command and data-handling system, and NASA may be able to activate it successfully so that data transmission resumes, Curie said. But if NASA relies solely on the backup channel, there would be no other options if it malfunctioned.

Work has begun to switch the telescope to the backup channel. It is a complicated process; the backup channels on the various modules that must be switched over have not been turned on since the late 1980s or early 1990, right before Hubble was launched. The Hubble team hopes to complete the job by the end of the week.

Curie stressed that the telescope is not in trouble; it just cannot send science information to ground controllers. That means NASA is unable to receive the dramatic pictures Hubble is known for.

The mission by Atlantis and a seven-person crew will be the fifth and final servicing mission to Hubble.

Now, Endeavour will be the next shuttle up, on a trip to the international space station in November. Endeavour is at the launch pad; it was supposed to serve as a rescue ship for Atlantis in case of trouble.





Untitled

21 09 2008
two shuttles on launch pads

Space Shuttle Endeavour is on standby (in the background) in case something happens on Atlantis’ mission to fix the Hubble telescope. (Credit: NASA/Jack Pfaller )

It’s not just a pretty picture. This NASA photo from Kennedy Space Center shows how, for the first time since July 2001, two shuttles are on launch pads at the same time. Atlantis is in the foreground on Launch Pad A, and Endeavour is behind it on Launch Pad B.

Endeavour was moved into position Friday so it could be on standby in the unlikely event that a rescue mission is necessary for the Atlantis’ planned October 10 mission to repair NASA’s Hubble Space Telescope, the agency said.

Once Endeavour is cleared from its rescue spacecraft duty, it’s scheduled to move to Launch Pad A for planned November 12 mission to the International Space Station.

What makes the Hubble repair mission particularly dangerous is that if Atlantis gets seriously damaged during flight, the seven astronauts would be stranded–they couldn’t just hang out at the International Space Station waiting for a ride.

Plus, as the Associated Press points out, Atlantis “faces an estimated 1-in-185 chance that a piece of space junk or a micrometeoroid will cause catastrophic damage to their ship.” Those odds are greater than for a typical shuttle flight because of Hubble’s unusually high and debris-filled orbit.