After postponing the Hubble Telescope servicing mission due
to an unexpected communications breakdown until at least February next year,
NASA started working on re-directing the flow of data from Hubble 18-year-old
486 system to a new backup system. The team of engineers began the switch operation
on Wednesday, at 9:30 a.m., after receiving positive telemetry.
On Wednesday night, the Space Telescope Operations Control
Center at the NASA Goddard Space Flight Center managed to turn on Side B of
Hubble’s Science Instrument Control and Data handling (SIC&DH) system, as
well as retrieve the Advanced Camera for Surveys (ACS), Wide Field Planetary
Camera 2 (WFPC2) and Near Infrared Camera and Multi-Object Spectrometer
(NICMOS) instruments from safe mode.
The second day of operations ended well, and NASA said that
by Friday, October 17, at noon, the review of the internal exposures for Hubble
should be completed. This review is considered a one last check of “transparency”
of switching to the redundant spacecraft electronics the Hubble team activated
on the first day, NASA explained.
NASA seemed very optimistic that the Hubble operations will
resume by the end of the week, although the first mission of Hubble after the
glitch still remains unknown. We will have to wait for an indefinite time for
the first images to be released of course, but the agency’s spokesperson said
that if everything goes according to plan, it will be sooner than later.
NASA’s final mission to Hubble until at least 2014 didn’t go
exactly as planned, and has been marked by repeated delays, first due to
weather problems, then due to technical problems. The Atlantis mission, which
was supposed to carry seven astronauts to Hubble this month, will have to stand-by
until next year to execute a set of repairs meant to keep Hubble up and running
for another 5 years at least.
In February, when hopefully everything will go smoothly and
according to plans, NASA’s astronauts will execute 5 six-and-a-half-hour
spacewalks to install the Wide Field Camera 3 (WFC3) and the Cosmic Origins
Spectrograph (COS). While the first images following the servicing missions
were initially expected in early 2009, it will probably take NASA longer than
that to release them.
The Wide Field Camera 3 will prove useful in the studies of
dark energy and dark matter, the formation of individual stars and the
discovery of remote galaxies which are currently beyond Hubble’s vision
capabilities. The Cosmic Origins Spectrograph will study galaxy evolution, the
formation of planets, the rise of the elements needed for life and the “cosmic
web” of gas between galaxies.
The Hubble mission started back in 1990, when the shuttle
Discovery launched and released the telescope into the orbit 304 nautical miles
above the Earth. Since then, it has circled around Earth over 97,000 times, and
has provided numerous answers in ways that would have been impossible from
Earth observations.
Update: Apparently, Hubble activation went in some troubles. "Activation of the Hubble Space Telescope science
instruments and resumption of science observations have been suspended
following two anomalies seen in systems onboard the telescope on
Thursday," NASA said in a statement. "All of the telescope's payloads
are back in safe mode condition while engineers perform troubleshooting. An
updated status report with more information will be issued shortly."
In a report posted on its website NASA said taht an anomaly occurred during the last steps of the
commanding to the Advanced Camera for Surveys. At 1:40 pm, when the low voltage
power supply to the ACS Solar Blind Channel was commanded on, software running
in a microprocessor in ACS detected an incorrect voltage level in the Solar
Blind Channel and suspended ACS.
Then at 5:14 pm, the Hubble spacecraft
computer sensed the loss of a "keep alive" signal from the NASA
Standard Spacecraft Computer in the SIC&DH and correctly responded by safing
the NSSC-I and the science instruments. It is not yet known if these two events
were related. The investigation into both anomalies is underway. All data has been collected
and is being analyzed.