U.S. astronauts trying to bring device back from dead

In this photo provided by NASA, astronaut Andrew Feustel, left, STS-125 mission specialist, navigates near the Hubble Space Telescope on the end of the remote manipulator system arm, controlled from inside Atlantis' crew cabin as astronaut John Grunsfeld, right, signals to his crew mate from just a few feet away, Saturday, May 16, 2009. Astronauts Feustel and Grunsfeld were continuing servicing work on the giant observatory, locked down in the cargo bay of the shuttle.(Agencies)

Astronauts are attempting their second in-orbit repair of a dead science instrument on the Hubble Space Telescope in as many days.

Astronauts Mike Massimino and Mike Good on Sunday morning plan to venture out of the space shuttle Atlantis to try to fix a long-dead spectrograph. The day before, two other spacewalkers successfully fixed a camera.

Massimino will remove 117 screws from the device. And he can't let any float away.

It's a repair job that was not part of the scientific instrument's design so NASA had to make dozens of special tools.

The device makes a fingerprint of cosmic objects by separating light. It is good for finding black holes and examining the atmosphere of planets outside our solar system.

(Agencies)