CAPE CANAVERAL, Fla. -- Two spacewalking NASA astronauts took on the role of orbiting opticians Thursday, outfitting the Hubble Space Telescope with a sharp new eye on the universe.

What's Next: Tonight in Space

Amid a fifth spacewalk in as many days, two shuttle astronauts will set out Friday to revive the Hubble Space Telescope's infrared camera-spectrometer, which has been dormant since 1999. Columbia mission specialists John Grunsfeld and Rick Linnehan will take on the job around 3:30 a.m. EST (0830 GMT). Their aim is to install an experimental cooling system for the observatory's Near-Infrared Camera and Multi-Object Spectrometer, also known as NICMOS. The instrument's original cooling system lost all its supercold nitrogen coolant within two years of its installation in 1997. Click here for mission updates and live NASA TV coverage beginning at 2:30 a.m. EST (0730 GMT) Friday.

Coming on the heels of a three-day electrical overhaul, James Newman and Michael Massimino fitted the telescope with a powerful planetary camera that will enable it to probe the deepest reaches of the cosmos.

"The first three days we gave Hubble the power, and now you've given Hubble the eyes," fellow astronaut John Grunsfeld told the spacewalkers from shuttle Columbia's cockpit.

"You did an excellent job," added crewmate Rick Linnehan. "You guys just paved the way for a lot of Ph.D.s in the years to come."

Ten times more powerful than its predecessor, the $76 million Advanced Camera for Surveys will allow the observatory to peer further into the universe than ever before.

Soon-to-be the scientific workhorse of Hubble, the massive instrument -- which is about the size of a telephone booth -- sports three specialized channels that are expected to shed new light on the origin, evolution and fate of the universe.

Unrivaled sky surveys will be conducted with its wide field channel as astronomers set out to study the nature and distribution of galaxies.

Its solar blind channel will search for hot stars and quasars while giving scientists an unprecedented capability to study the weather on planets in our own solar system.

And the camera's high-resolution channel will suppress bright light from celestial objects, enabling astronomers to search for Earthlike planets around distant stars as well as entire galactic neighborhoods hidden in the glare of brilliant quasars.

Set to begin observations after an impending nine-week checkout, the digital camera will zoom in on celestial objects far beyond the reach of Hubble's current instruments, generating images and data three to four times faster.

"With ACS, Hubble will detect more faint stars and galaxies in its first 18 months than have been detected with all of the previous Hubble instruments," said Johns Hopkins University astronomer Holland Ford, who led the team that built the camera.

"For astronomers, those stars and galaxies in the data archive are money in the bank."

The camera installation work came amid the fourth spacewalk in as many days for Columbia's seven astronauts, who launched into space last Friday and caught up with Hubble two days later.

With the four-story telescope mounted to a shuttle cargo bay work stand, Newman and Massimino set out on their excursion at 4 a.m. EST (0900 GMT) as Columbia crossed onto the night side of the planet over the Indian Ocean, the sun at its tail.

"Looks like a beautiful night for a spacewalk," Newman said after he and Massimino floated into the shuttle bay, helmet lights ablaze.

The two then set out to remove Hubble's Faint Object Camera from a compartment at the butt of the observatory, a job that required unique expertise in weightless mass handling.

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