Hubble engineers at the telescope's mission control center in Greenbelt, Md., have spent the last few weeks since
the Sept. 27 failure of the orbital observatory's main data transmission channel reviewing procedures to switch to a backup system, with a final center meeting set for today. Mission engineers also met Thursday discuss the plan, with top NASA officials expected to give a final review on Tuesday."We are still marching forward in our process," said Ed Campion, a spokesperson at NASA's Goddard Space Flight Center, which oversees Hubble operations. "Right now, I would characterize the things that came out of that meeting yesterday as positive and we're planning on moving forward."
Hubble's science silence stems from the loss of the Side A channel in a device called a Control Unit/Science Data Formatter, which failed for good last month after 18 years of service since the space telescope's launch in 1990. There is a backup, Side B, but switching to that channel is an arduous process that includes moving five separate systems to the same string as well.
The failure forced NASA to delay plans to launch seven astronauts to Hubble aboard the space shuttle Atlantis on one last service call on the orbital observatory. The shuttle was slated to launch on Oct. 14, but will now lift off no earlier than early 2009.
"They are taking a very detailed look at everything that is involved in making this switchover to Side B," Campion said.
If top NASA officials sign off on the systems switch on Tuesday, engineers could begin the Side B activation as early as Wednesday morning, he added.
"It's a pretty lengthy process," Campion said. "They've described this as being like a 40-some-hour process."
Meanwhile, a separate team of engineers is continuing work to study a spare for the failed data formatter that has been in storage at Goddard for the last two decades.
NASA wants to ensure the spare unit is spaceworthy and in working order before including it aboard the space shuttle Atlantis to be added among the other upgrades planned for Hubble's last overhaul. The agency is expected to brief the public on its Hubble repair plan in a televised briefing on Tuesday at 12:30 p.m. EDT (1630 GMT).
Commanded by veteran astronaut Scott Altman, Atlantis' astronaut crew plans to perform five back-to-back spacewalks to install new cameras, replace aging batteries and broken gyroscopes, upgrade Hubble's guidance system and add a docking ring to the space telescope. The astronauts also plan to attempt to fix instruments never designed for in-space repairs and hope to extend Hubble's mission through at least 2013.
With Atlantis' launch to Hubble delayed to next year, NASA has turned its attention to the next shuttle flight - STS-126 aboard Endeavour. That mission is due to launch toward the International Space Station on Nov. 14 to deliver new life support equipment and supplies designed to allow the orbiting laboratory to expand to larger, six-person crews.
SPACE.com -- NASA Draws Plan to Revive Hubble Space Telescope
