Image: Astronaut John Grunsfeld
Astronaut John Grunsfeld stand on a foot restraint and prepares to replace a radio transmitter on the Hubble Space Telescope.
By Staff Writer
updated 1/23/2007 12:02:40 PM ET 2007-01-23T17:02:40

If things go according to plan, the Hubble Space Telescope will undergo its fifth tune-up in 2008, more than 16 years after deployment.

For astronaut John Grunsfeld, who will be onboard, the mission has both personal and scientific meaning. This being his third time to the orbiting telescope, Grunsfeld calls himself "literally a Hubble hugger."

Hubble orbits 360 miles above Earth. It weighs as much as two adult elephants. And it is equipped with an arsenal of science instruments that have produced an unprecedented string of scientifically useful and universally popular photographs and other data. During its lifetime, Hubble has completed about 93,500 trips around the planet, taking three-quarters of a million snapshots and probing 24,000 celestial objects and phenomena.

“Hubble has truly transcended just being an astronomer’s tool for science," Grunsfeld said in a recent interview here at the Space Telescope Science Institute, command central for the orbiting observatory. “It is an icon for science and as I travel around the country or around the world, people know Hubble — people have an idea of what Hubble does, people recognize that it’s important.”

That's why Grunsfeld took it so hard when this Hubble servicing mission was initially cancelled by former NASA Administrator Sean O’Keefe after the deadly shuttle Columbia accident in February 2003.

The announcement instigated a chorus of protest from the public, politicians and the astronomical community. “The decision hit me in the head like a two-by-four," Grunsfeld said then.

Time is short
Time is running out for Hubble. The batteries are nearly depleted, its steer-controlling gyroscopes are shutting down one-by-one and the wear and tear from years in space is taking its toll. Without some serious TLC — tasks slated in the proposed service mission — Hubble might cease to function as a science instrument anytime in the next year or two. Eventually, without installation of a mechanism to bring the telescope back to Earth safely it would spin out of control.

Slideshow: Month in Space: January 2014 “This is a very complex observatory that requires lots of care and feeding,” Grunsfeld said.

So ever since the service mission was cancelled, Grunsfeld and others have fought to have it reinstated. Behind the scenes, he lobbied and ultimately convinced O’Keefe to consider a robotic mission to Hubble.

Mike Griffin, who stepped in as O'Keefe’s replacement in April 2005, ultimately put a full-blown service mission back on the agenda. After lengthy analyses of the safety of sending a shuttle mission to Hubble, the NASA Administrator gave the green light last October.

The mission is expected to breathe years of additional life into Hubble, extending its expiration date to 2013.

Risky business
One reason the Hubble mission underwent such thorough scrutiny is due to an inherent risk factor.

For most shuttle missions, the craft gets launched into an orbital trajectory that allows it to reach the international space station if necessary. “You can live on the station a long time while we figure out other ways to get people back down,” Grunsfeld said. But the Hubble telescope is in a different orbit, and the shuttle would be out of reach of the station.

“That’s why Hubble really is a risky mission," Grunsfeld said. "What Mike Griffin has decided is we will do Hubble because we believe the shuttle is safer than it’s ever been.”

A second shuttle will be prepared to launch in the event a rescue is needed. “We still realize that it’s a risky business,” Grunsfeld said.

Hubble tune-up
Over a series of five spacewalks, astronauts will complete nuts-and-bolts work to keep Hubble alive.

They will also install two new instruments: the Wide Field Camera 3, which has visible, near-UV and near-infrared capabilities; and the Cosmic Origins Spectrograph, which will use ultraviolet vision to study the formation and evolution of galaxies and ultimately how the universe’s structure has changed over time.

For Grunsfeld, the most significant and trickiest task will be to revive the Space Telescope Imaging Spectrograph  which conked out after a power failure in August 2003.

Installed on Hubble in February 1997, the STIS separates incoming light into its constituent colors, giving astronomers a chemical map of a distant object. Since deployed, STIS has been critical in the confirmation of black holes at the centers of galaxies, made the only discovery of an atmosphere around an exoplanet and helped confirm the age of the universe.

The repair job would typically be completed in a clean room, where mechanics would don sterile garbs and be equipped with tiny screwdrivers. The instrument is too bulky to even move it into the shuttle for repairs.

“The first problem is that the power supplies are deep in the instrument and behind covers," Grunsfeld said. "If we could take STIS out of Hubble and bring it to the shuttle it would be relatively straightforward, but you can’t do that."

The most optimal power supply for replacement is beneath a cover plate mounted to the instrument with more than 100 tiny screws and washers. “And that’s the kind of thing we have no capability to do with the current set of tools," he said. "So we’ve developed a new power tool— a mini power screwdriver—and ways of grabbing these screws so they don’t get loose inside the telescope, which could be disastrous."

Image: Hubble Space Telescope
NASA via AFP - Getty Images file
NASA has decided it will make one last service call to the Hubble Space Telescope. The launch is tentatively scheduled for no earlier than May 2008.
Once this sweat-dripping operation is complete, the astronaut can change out the power-supply card — and the real fun begins.

“The card has 300 or so tiny gold pins on the back for replacement that we have to slide in. But you can’t really see it because we have on these huge bubble helmets. You can’t get your head in there with a tiny flashlight. So it’s going to be hard,” he said.

Grunsfeld and other service team members have practiced the repairs for hours and hours in a simulated environment. With a background in ballooning, Grunsfeld said he has experience reaching into instruments and completing repairs like this one without stereo vision.

Close connection
In addition to Grunsfeld, the crew will consist of mission commander Scott Altman, Gregory Johnson, Andrew Feustel, Michael Good, Michael Massimino and K. Megan McArthur.

Who will complete the STIS repairs? That is still up in the air, but Grunsfeld said he’d like to do it.

Even with a tune-up, Hubble won’t last forever. After shutting down, HST is planned to remain in orbit until at least 2021 until it is allowed to splash down into the ocean.

Grunsfeld hopes to be there to say goodbye when that happens: “I hope there’s a cruise that goes out to the Pacific. We’ll get out our walkers and sit on the deck and watch Hubble re-enter and we’ll have a huge party. Maybe in the meantime we’ll service it again.”

Even after a splashdown, Hubble will stay alive, if only in history books. “If we look ahead 500 or 1,000 years and imagine Encyclopedia Galactica some student might be reading, and he’s going to read about the major advancements in science through humankind, and there’ll probably be a picture of Galileo looking through the first telescope that he used for astronomy.”

“But Hubble will definitely be there as this paradigm-changing, mind blowing telescope that people made that really changed the history of humankind, and I think it’s neat to be a part of that.”

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Photos: Classic Hubble Hits

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  1. Happy birthday, Hubble!

    The Hubble Space Telescope is celebrating its 20th birthday and we have some images taken by the iconic space observatory over the past two decades. Arp 148, shown here, is the staggering aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. This image is part of a collection of 59 images of merging galaxies taken by Hubble and released on its 18th anniversary. (NASA/ESA/Hubble Heritage Team) Back to slideshow navigation
  2. Swirling merger

    AM 0500-620, located 350 million light-years away from Earth, consists of a highly symmetric spiral galaxy seen nearly face-on and partially backlit by a background galaxy. (NASA/ESA/Hubble Heritage Team) Back to slideshow navigation
  3. Galactic duet

    This Hubble image displays a beautiful pair of interacting spiral galaxies with swirling arms. The smaller of the two, dubbed LEDA 62867 and positioned to the left of the frame, seems to be safe for now, but will probably be swallowed by the larger spiral galaxy, NGC 6786 (to the right) eventually. (NASA/ESA/Hubble Heritage Team) Back to slideshow navigation
  4. Spiraling galaxies

    This image shows a Hubble view of Arp 272, a remarkable collision between two spiral galaxies, NGC 6050 and IC 1179. The galaxy cluster is part of the Great Wall of clusters and superclusters, the largest known structure in the Universe. The two spiral galaxies are linked by their swirling arms. (AP) Back to slideshow navigation
  5. Tail of stars

    NGC 520 is the product of a collision between two disk galaxies that started 300 million years ago. It exemplifies the middle stages of the merging process: the disks of the parent galaxies have merged together, but the nuclei have not yet coalesced. It features an odd-looking tail of stars and a prominent dust lane that runs diagonally across the center of the image and obscures the galaxy. (NASA via Reuters) Back to slideshow navigation
  6. Galactic merger

    This is the sharpest image yet from the Hubble Space Telescope of the merging Antennae galaxies. As the two galaxies smash together, billions of stars are born, mostly in groups and clusters of stars. The brightest and most compact of these are called super star clusters. (NASA / ESA / STSI via Reuters) Back to slideshow navigation
  7. Starburst galaxy

    This photo of the starburst galaxy, Messier 82 (M82) is the sharpest wide-angle view ever obtained of M82, a galaxy remarkable for its webs of shredded clouds and flame-like plumes of glowing hydrogen blasting out from its central regions. Located 12 million light-years away, it is also called the "Cigar Galaxy" because of the elongated elliptical shape produced by the tilt of its starry disk relative to our line of sight. (NASA / ESA via AP) Back to slideshow navigation
  8. Stellar spiral

    This Hubble Space Telescope image released February 28, 2006, shows the spiral galaxy of the Messier 101. It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble. (NASA / ESA via Reuters) Back to slideshow navigation
  9. A starry night

    This image bears remarkable similarities to the Vincent van Gogh work, "Starry Night" complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space. The Advanced Camera for Surveys is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). V838 Mon is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy. (NASA / The Hubble Heritage Team) Back to slideshow navigation
  10. A brilliant white

    NASA's Hubble Space Telescope trained its eye on one of the universe's most stately and photogenic galaxies, the Sombrero galaxy with the space telescope's Advanced Camera for Surveys , in May-June 2003 . The image of the galaxy's hallmark brilliant white, bulbous core is encircled by the thick dust lanes comprising the spiral structure of the galaxy. (NASA / The Hubble Heritage Team) Back to slideshow navigation
  11. Glowing dust

    This dramatic image offers a peek inside a cavern of roiling dust and gas where thousands of stars are forming. The image, taken by the Advanced Camera for Surveys aboard the Hubble Space Telescope, represents the sharpest view ever taken of this region, called the Orion Nebula. (NASA / ESA / STScI / ESA) Back to slideshow navigation
  12. Pillars of creation

    Columns of cool hydrogen gas in the Eagle Nebula serve as the incubators for new stars - which look like tiny bubbles within the dark pillars. (NASA / AURA / STSCI) Back to slideshow navigation
  13. Cosmic comets

    In the left image, the Cartwheel Galaxy looks like a wagon wheel in space. A more detailed image of the galaxy"s hub shows bright, comet-like clouds circling at nearly 700,000 mph. (NASA / AURA / STSCI) Back to slideshow navigation
  14. A nebula's neon colors

    A nebula known as the Cygnus Loop is actually the expanding blast wave from a supernova. The blast has hit a cloud of dense interstellar gas-causing the gas to glow. (NASA / AURA / STSCI) Back to slideshow navigation
  15. Helix Nebula

    Pictured is an image of the Helix Nebula showing tremendous detail of its mysterious gaseous knots. The cometary knots have masses similar to the Earth but have radii typically several times the orbit of Pluto. (NASA / AURA / STSCI) Back to slideshow navigation
  16. Ballooning star

    Eta Carinae was the site of a giant outburst observed from Earth about 150 years ago, when it became one of the brightest stars in the southern sky. The star survived the explosion, which produced two billowing clouds of gas and dust. (NASA / AURA / STSCI) Back to slideshow navigation
  17. Clouds of glory

    HH 32 is an excellent example of a "Herbig-Haro object," which is formed when young stars eject jets of material back into interstellar space. The jets plow into the surrounding nebula, producing strong shock waves that heat the gas and cause it to glow in different colors. (NASA / AURA / STSCI) Back to slideshow navigation
  18. Eye of heaven

    This celestial object, with the scientific name MyCn18, looks like an eerie green eye staring out from two intersecting rings. But it's actually an intricately shaped "hourglass" nebula with a star at its center. (NASA / AURA / STSCI) Back to slideshow navigation
  19. Stormy weather

    Temperature differences within interstellar clouds of gas and dust can result in structures reminiscent of Earth's tornadoes. Here are some twisters in the heart of the Lagoon Nebula. (NASA / AURA / STSCI) Back to slideshow navigation
  20. Sunny side up

    The small spiral galaxy NGC 7742 is probably powered by a black hole residing in its core. The core of NGC 7742 is the large yellow "yolk" in the center of this fried-egg image. (NASA / AURA / STSCI) Back to slideshow navigation
  21. Feeding a black hole

    A spiral-shaped disk of dust fuels what scientists believe is a black hole near the center of the galaxy NGC 4261. The material heats up and glows as it swirls around the black hole. (NASA / AURA / STSCI) Back to slideshow navigation
  22. Light up the night

    Like lanterns in a cavern, scores of hot stars light up the gaseous walls of the nebula NGC 604. The nebula is a prime area for starbirth in an arm of the spiral galaxy M33. (NASA / AURA / STSCI) Back to slideshow navigation
  23. Supernova circuits

    Three rings of glowing gas encircle the site of supernova 1987A, a star that was seen to explode in 1987. Though the rings appear to intersect, they are probably in three different planes. (NASA / AURA / STSCI) Back to slideshow navigation
  24. Surrealistic Saturn

    A false-color image shows infrared light reflected from the planet Saturn. The different hues help scientists discern different levels of the planet's thick atmosphere. Two of Saturn's moons - Dione and Tethys - are visible as specks on the image. (NASA / AURA / STSCI) Back to slideshow navigation
  25. Jupiter's aurora

    A curtain of glowing gas is wrapped around Jupiter's north pole like a lasso in a Hubble Space Telescope image captured in 1998. The curtain of light, called an aurora, is produced when high-energy electrons race along the planet's magnetic field and into the upper atmosphere. The electrons excite atmospheric gases, causing them to glow. A similar aurora crowns Earth's polar regions. (NASA) Back to slideshow navigation
  26. Cosmic Horsehead

    The Horsehead Nebula is one of the most photographed objects in the sky. The Hubble Space Telescope took a close-up look at this heavenly icon, revealing the cloud's intricate structure. This view of the horse's head was released April 24, 2001, to celebrate the observatory's 11th anniversary. Hubble was launched by the shuttle Discovery on April 24, 1990. (NASA via Reuters) Back to slideshow navigation
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