material for Flight Day 8 -
Cooling System (NCS)
Goddard Space Flight Center
The Hubble Space Telescope Project
Hubble Status Report
| Mar. 8, 2002 - 10:51 pm EST
In today's EVA #5, Shuttle astronauts John Grunsfeld and Richard
Linnehan installed a mechanical cooling system to revive NICMOS,
an infrared-sensitive camera originally placed on the telescope
in February 1997.
For a period of nearly two years extending into early-1999,
NICMOS obtained extremely valuable data on the birth and death
of stars, the formation of dusty disks around stars from which
planets eventually form, and the properties of extremely distant
galaxies near the edge of the observable universe. The cooling
system passed its aliveness and functional tests during today's
Infrared instruments such as NICMOS need to be cooled to very
low temperatures to suppress thermal radiation from the instrument
itself which can overwhelm faint light emitted by astronomical
NICMOS was originally cooled passively by means of a tank
of solid nitrogen ice which was expected to last for approximately
five years. Due to a heat leak which melted the ice faster
than anticipated, the operable life of the instrument was
reduced to a little under two years.
The NICMOS Cooling System uses a mechanical cooler run off
of electrical power to pump extremely cold neon gas through
the NICMOS instrument. Comparison of the new "cryocooler"
to the original solid ice cooling method for NICMOS is essentially
the same as the comparison of a refrigerator to the icebox
of one hundred years ago.
Cryocoolers are felt to have a promising future in space,
but their ability to operate over long durations in space
has not yet been demonstrated. In addition to reviving the
very important infrared capabilities of Hubble and NICMOS,
the cooling system will hopefully be a trailblazer for this
very important technology in space.
The Hubble Space Telescope Program wishes to express its sincere
thanks to the Shuttle astronauts and the Johnson Space Center
for its superb performance in this incredible five-EVA Servicing
Mission. It is one for the record books.
Watch for the deployment of Hubble around 4:30 am EST on Saturday
Space News :: Latest Items
| Mar. 8, 2002 - 9:58 am EST
The aliveness test for the entire Nicmos Cooling System was
completed successfully. After close-out is finished, the astronauts
will have a few statements for back home and return to the
shuttle. This is possibly there last EVA of the mission.
Deployment of Hubble will occur around 4:30 am EST tomorrow.
| Mar. 8, 2002 - 5:05 am EST
The Nicmos Cryogenic Cooler (NCC) was installed a short while
ago inside of Hubble. Grunsfeld and Linnehan then proceed
to fit the NCS radiator to the side of Hubble and work on
making the connections between Nicmos, the NCC, and the radiator.
| Mar. 8, 2002 - 3:18 am EST
Columbia Astronauts John Grunsfeld and Richard Linnehan began
the fifth spacewalk of the STS-109 mission Friday at 2:26
During the 6 1/2-hour spacewalk they will install an experimental
cryogenic cooler and an associated radiator. The system is
designed to revive the Near-Infrared Camera and Multi-Object
Spectrometer of the Hubble Space Telescope. The instrument
has been inactive since 1999, when its coolant was exhausted.
| Mar. 8, 2002 - 3:00 am EST
The crew of the space shuttle Columbia will give Hubble a
way to open one of its slumbering eyes during the fifth and
final scheduled spacewalk of this mission. An experimental
cooling system will be installed on a camera that has been
dormant since 1999 in hopes of bringing it back to life.
Astronauts John Grunsfeld and Rick Linnehan plan to step out
into the shuttle’s payload bay about 2:30 a.m. CST Friday.
The objective of the 6 1/2 hour spacewalk is to install the
Near Infrared Camera and Multi-Object Spectrometer (NICMOS)
Cooling System - the NCS for short, which consists of two
main components - the NICMOS Cryogenic Cooler (NCC) and the
Grunsfeld will retrieve the NCC from the shuttle's payload
bay and both spacewalkers will install the unit inside the
telescope (port axial bay). They will then retrieve and install
the large flat NCS radiator on the outside of Hubble.
Todays spacewalk is the fifth and final scheduled spacewalk.
reports about this mission day