This
story was updated 5:45 p.m. EST.
The Hubble Space Telescope's
primary camera is offline, with some science capabilities likely lost for good,
NASA officials said Monday.
An electrical
short in the backup system for Hubble's Advanced
Camera for Surveys (ACS) pushed the space telescope into a protective "safe
mode" over the weekend and prompted the formation of an Anomaly Investigation
Board on Monday, NASA officials said.
The
incident, the third since June to hobble Hubble's ACS camera, occurred at 7:34
a.m. EST (1234 GMT) on Jan. 27. Engineers managed to switch the space telescope
back to normal operations, with the exception of the ACS instrument, by Sunday and
hope to resume science observations with the observatory's remaining instruments
later this week.
NASA has convened an Anomaly Review Board
to go over Hubble's latest malfunction, the results of which are expected to be
presented by March 2.
"Obviously,
we are very disappointed by this latest event because of the popularity of the
ACS instrument with astronomers," NASA's Preston Burch, Hubble program manager
at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland, told
reporters today in a teleconference.
It was
Hubble's ACS camera's wide field channel, for example, that allowed astronomers
to generate Hubble's
Ultra Deep Field - the deepest view into the universe to date. But that ACS
channel, and a high-resolution channel used to study stars surrounded by planet-forming
material, are likely lost since the latest glitch has cut off power to
their systems, Hubble managers said.
"We're not
optimistic at all that those will be restored," said David Leckrone, NASA's
senior project scientist for Hubble at the GSFC. "The saving grace here is that
we have a superb new wide field camera coming along that was originally
designed, in fact, to be a back up for ACS in case ACS failed. It was designed
to work in tandem with ACS if [it] was full alive."
That new camera
- known as Wide
Field Camera 3 - is due to be installed at Hubble during NASA's last space shuttle flight to the
observatory in September
2008.
Hubble
engineers hope they will be able to restore partial ACS science capability with
its third feature - the Solar Blind channel used recently to study auroras on Jupiter and Saturn - by February to aid NASA's
New Horizons mission, which is due to make a close
flyby of Jupiter on Feb. 28.
"As soon as
we're confident that everyone has done their homework on that, we could very
have the Solar Blind operating by the end of February," Burch said. "That would
be the hope."
Hubble's
other, non-ACS instruments - the Field Planetary
Camera 2, Near Infrared Camera Multi-Object Spectrograph, and the Fine Guidance
Sensors - are unaffected by the recent glitch.
Hubble's
camera troubles
Hubble's
ACS camera has been working on its backup, or Side B, system since the instrument's
primary Side A electronics encountered a malfunction in June
2006. An electronics hiccup a few months later in September again knocked the
camera offline, but the system recovered a short time later.
NASA Hubble
managers said the most recent glitch is a completely isolated incident and is
not connected to the earlier problems.
"It's very
different," Burch said, adding that the current anomaly's signature is very
different from those seen last year.
Hubble
managers have also prepared about six observation surveys that do not require
the ACS camera just in case the finicky instrument went offline. Those research
projects will now be implemented while the camera is unavailable.
The ACS anomaly comes just two months before the instrument's projected
five-year warranty expired, Hubble managers said. Spacewalking astronauts installed
the camera on March 7, 2002 during NASA's STS-109
mission aboard the Columbia orbiter. Launched
in 1990, the Hubble Space Telescope has been billed as one of the most valuable astronomical
instruments of all time and is the product of a partnership between NASA and the European Space Agency.
"It's
certainly been an astounding success as an instrument," Rick Howard, acting
director of NASA's Astrophysics Division at NASA's headquarters in Washington,
D.C., adding that the camera met about all of its initial science objectives
before its recent failure.
Because of
the ACS camera's hard-to-reach location on Hubble and the already packed
five-spacewalk schedule of NASA's final servicing
mission to Hubble - Servicing Mission 4 slated to launch in September 2008 -
adding a new and complicated repair job to the spaceflight is not an attractive
option, Burch said.
"Servicing
Mission 4 is a very full mission with installing new batteries and gyroscopes,
installing one of the fine guidance sensors and two new instruments," Burch
said, adding that the initial plan carries no ACS-related additions to the
upcoming Hubble overhaul.
Leckrone
said that the new instruments to be grafted into Hubble during Servicing
Mission 4 (SM-4) will almost completely restore the telescope's lost ACS
abilities, though the new Wide Field Camera 3 will take longer to generate its
predecessor's stunning views of the universe.
"The
successful completion of SM-4 and insertion of Wide Field Camera 3 will take us
fully back to not only where we are now, but where we want [Hubble] to be in
the future," Leckrone said.
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