Live In Orbit: Hubble Outfitted With Last Instrument

A super-sensitive spectrograph that's expected to shed light on mysterious dark matter is electrically alive inside NASA's Hubble Space Telescope today after a successful installation.

Spacewalkers Drew Feustel and John Grunsfeld teamed up to install the $88 million Cosmic Origins Spectrograph, which is designed to study that "cosmic web" that holds all matter in the universe together. It is expected to help scientists determine the nature of dark matter, the mysterious form of energy that appears to account for 90 percent of the mass of the universe.

The COS also will detect faint light from faraway quasars and provide greater insight into how planets, stars and galaxies form.

"We haven't said a lot about COS and it's sort of the quiet instrument back in the background waiting to come out and be a super star," said David Leckrone, senior Hubble project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

"COS is the most sensitive spectrograph ever to fly in space," he added. "A spectrograph is kind of a poor relative to a camera. It doesn't take pretty pictures. It merely produces precise, quantitative astrophysical data on everything in the sky that we point it to."

Anchored to the end of the robot arm of shuttle Atlantis, Feustel hoisted the instrument -- which is the size and shape of a phone booth -- and slid it into one of the telescope's axial bays.

"Great job. Excellent," said shuttle mission specialist Mike Massimino, who was directing the spacewalking work from the aft flight deck at Atlantis. "Good work, boys."

The astronauts then went on to stow the Corrective Optics Space Telescope Axial Replacement, or COSTAR, in a protective canister for the return trip home.