Wednesday, May 20, 2009

Hubble Is Now Free

Atlantis's manipulator arm lifts the Hubble Space Telescope out of its cargo bay just prior to launching it into orbit. Image credit: NASA

Yesterday, the space shuttle Atlantis released the Hubble Space Telescope from its cargo bay, and set it on its way to make more observations of the universe:

Rejuvenated by hours of repairs in space, the Hubble Space Telescope floated out of shuttle Atlantis' cargo bay on Tuesday to reclaim its place as the world's flagship observatory for astronomical research.

Atlantis astronauts spent more than 36 hours over five marathon spacewalks to make upgrades and outfit Hubble with new instruments. These included a panchromatic wide-field camera that should be able to see objects formed just 500 million years after the universe's birth in the big bang explosion some 13.7 billion years ago.

Astronauts Release Hubble Telescope Back Into Space

This mission saw more than the usual run of difficult tasks. In particular, there were repairs done on two instruments that were never designed to be repaired in space:

The Atlantis crew completed everything NASA had planned, including the unprecedented repair of two science instruments not designed to be worked on in space. The astronauts, clad in bulky suits and gloves, sometimes struggled with the repair work, and were held up at times by stuck bolts.

Astronauts Release Hubble Telescope Back Into Space

Image credit:NASA, reduced by Cujo359

NASA engineers had to design a new power tool to effect some repairs on the HST:

Nothing in the astronaut’s regular tool kit could remove so many fasteners in a short time, Cassidy said. The pistol-grip tool, which is NASA’s version of a cordless drill, turns about 15 times a minute on the high side. It’s a staple for space construction, but could not do the job fast enough on the Hubble servicing flight. Engineers wanted at least 10 times that speed, but didn’t need the torque the pistol-grip tool generated.

"With these fasteners, you don’t need a really strong motor to break them free, but what you need is a really, really fast motor to be able to, basically like an Indy pit crew, to be able to buzz through all these fasteners in a very rapid succession of time," Cassidy said.

They also needed something to corral all the fasteners as they came loose. Otherwise, they might float into something critical inside the telescope and cause a problem.

It took four to five years to develop the mini power tool and the fastener capture plate, Cassidy said. The power tool spins at 210 revolutions per minute. The capture plate, meanwhile, was designed to work with the fastener tools and simply collects each fastener as it is removed.

Hubble Flight Tests Toolmakers

The HST will now have to be set up for several months before it can start making new observations:

While activities here in the [Space Telescope Operations Control Center] in support of the telescope and the space shuttle are nearing a conclusion, the science mission orbital verification work involving detailed checkouts, alignments and focusing of the new instruments is expected to take several months to complete.

Hubble scientists expect the first "new" images to be released in September.

Space Telescope Operations Control Center: Flight Day 8

For now, we'll have to do with the desktop backgrounds we already have ...

While this mission required tremendous planning and training to complete, it still serves to demonstrate what is possible for us to do in space, even with current technology. In a way, this is a sad occasion, since there will be no more shuttle missions to the HST. It's quite possible that there will be no more repair missions, since there are no other manned vehicles either in existence or in design that have anywhere near its capacity. That we haven't followed up with an improved space shuttle design by now, after more than twenty years, is a shame.

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