Astronauts to undertake fourth walk to repair Hubble telescope

May 17, 2009 by Mark Carreau
In this image obtained from NASA video, astronauts work to service the Hubble space telescope. US astronauts will undertake a fourth in a series of five daily spacewalks intended to equip the 19-year-old Hubble Space Telescope for at least another five years of valuable scientific work

US astronauts on Sunday will undertake a fourth in a series of five daily spacewalks intended to equip the 19-year-old Hubble Space Telescope for at least another five years of valuable scientific work.

Fellow spacewalkers Mike Massimino and Mike Good will attempt an intricate repair of Hubble's Space Telescope Imaging Spectrograph, a black hole hunter.

The spectrograph was installed in the telescope during a 1997 shuttle mission but has been inactive since a 2004 power failure.

The repair plan is similar to the one that revived the Advanced Camera for Surveys on Saturday. However, Massimino must extract 111 small screws without losing a single one.

The spacewalk is scheduled to begin at 9:16 am EDT (1316 GMT) and will last approximately six and a half hours.

On Saturday, another pair of astronauts, John Grunsfeld and Drew Feustel, revived the crippled camera and installed a second new scientific instrument aboard the Hubble.

Since hoisting Hubble into Atlantis's cargo bay last week, the shuttle's seven astronauts have achieved six of the mission's highest priorities.

In addition to the Saturday's camera revival and installation of the new Cosmic Origin Spectrograph, the list of achievements include the addition of the Wide Field Camera-3, a new , and power storage batteries.

Hubble, a cooperative project between NASA and the European Space Agency, is headed for a new scientific summit, a perch from which astronomers can search for the oldest star systems, map the large scale structure of the universe and study planet forming processes around other stars.

"We are batting 1,000," said Dave Leckrone, NASA's chief Hubble astronomer, told a news briefing. "We have just an extraordinary capability to image the universe, much more powerfully that what we had before by far."

Saturday's spacewalk breathed new life into the camera for surveys, a seven-year-old instrument that was crippled by a short circuit in January 2007.

The breakdown slowed a campaign to unravel the mysteries of and , two little understood forces that influence the structure and expansion of the universe.

During the repair, Grunsfeld, a 50-year-old astronomer, and Feustel, a 43-year-old geologist, opened the camera to extract and replace four circuit boards and attach a new external power source.

Grunsfeld, who is visiting the space telescope for a third time, removed 32 tiny screws using an assortment of hand ratchets and cutters to revive the imager. A custom cover plate kept the tiny fasteners from floating into the telescope, where it could have caused harm.

Saturday's outing began with the installation of the new Cosmic Origins Spectrograph, an instrument that analyzes the light from stars, planets and other astronomical objects rather than taking pictures.

The new instrument will rely on the light from distant quasars to illuminate the vast web-like structures that extend across the universe encircling regions of interstellar gas and dust.

The new spectrograph promises to aid astronomers as they track the stellar genesis of carbon and the other chemical elements needed for life.

The spacewalkers made room for the spectrograph by removing an optical module installed in Hubble in 1993.

Astronauts on the long ago mission equipped the observatory with the Corrective Optics Space Telescope Axial Replacement, an instrument that overcame an optical flaw in the telescope's light gathering mirror.

The flaw surfaced in the weeks following Hubble's 1990 launch.

In Saturday's there was a notable absence of the stuck bolts and equipment misalignments that marred spacewalks on Thursday and Friday and pushed the outings well beyond their planned six and a half hour limits.

(c) 2009 AFP

Explore further: Computer simulation suggests early Earth bombarded by asteroids and comets

add to favorites email to friend print save as pdf

Related Stories

Spacewalkers equip Hubble with new computer

May 15, 2009

Spacewalking astronauts upgraded the Hubble telescope for the first time in seven years, equipping the 19-year-old stargazer with a powerful new camera and science computer.

Spacewalkers pull off toughest Hubble repairs yet

May 16, 2009

(AP) -- Spacewalking astronauts gave the Hubble Space Telescope a better view of the cosmos by installing a new high-tech instrument Saturday, then pulled off their toughest job yet: fixing a broken camera.

New Science Instruments for Hubble

Oct 16, 2007

To enhance the Hubble Space Telescope’s science capabilities, two new instruments – the Wide Field Camera 3 and Cosmic Origins Spectrograph - will be installed during the fifth and final shuttle servicing ...

Recommended for you

Rosetta measures comet's temperature

9 hours ago

(Phys.org) —ESA's Rosetta spacecraft has made its first temperature measurements of its target comet, finding that it is too hot to be covered in ice and must instead have a dark, dusty crust.

How Rosetta arrives at a comet

11 hours ago

After travelling nearly 6.4 billion kilometres through the Solar System, ESA's Rosetta is closing in on its target. But how does a spacecraft actually arrive at a comet?

Lunar occultation of Saturn

11 hours ago

On the night of Monday August 4, mainland Australia will see Saturn disappear behind the moon. It's the third time this year that the moon and Saturn will perfectly line up, as viewed from our part of the ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

yyz
not rated yet May 17, 2009
Fingers crossed that Hubble%u2019s Space Telescope Imaging Spectrograph (STIS) is successfully repaired on today%u2019s (Sunday) spacewalk. Its super-high resolution spectra are just what%u2019s needed to probe the constituents of planetary atmospheres on transiting planets discovered by Kepler, and to look closely at other known transiting exoplanets. STIS observations of a single transiting exoplanet provided the first characterization of an exoplanets atmosphere.
SparkyMetal
not rated yet May 18, 2009
They did it! I hoped, but didn't really think they'd be able to, pull off today's walk. These guys are heros :) Hope the next one is equally successful & they get back safe and sound.