
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, April 27, 1990                   TAG: 9004270965
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A/1   EDITION: EVENING 
SOURCE: Associated Press
DATELINE: SPACE CENTER, HOUSTON                                LENGTH: Medium

LENS IS OPEN, HUBBLE SET TO SEE UNSEEN

The lens cover on the Hubble Space Telescope opened this morning, eliminating the prospect for a spacewalk repair job by Discovery astronauts after a morning of worrisome problems.

"We have confirmation from the Space Telescope Operations Control Center that the aperture door is open," said John Dumoulin of the Goddard Space Flight Center.

The space shuttle Discovery, which carried the telescope to orbit, was 50 miles behind the telescope, ready to lend a hand if needed.

"It appears the crew will be the last to know they will not rendezvous, that the telescope's aperture door has been successfully opened," said mission control's Jeff Carr.

Discovery was out of touch with the ground because the commands to the telescope were being sent through the Tracking and Data Relay Satellite, which is also used for shuttle communications.

The lens cover, a 10-foot diameter "aperture door," covers the opening to the telescope's light shield. When it is closed, the telescope is blind.

Soon after the door's opening, another problem developed.

Two of the four "rate gyros" that steady the telescope and lock it into position failed. When that happens, the telescope automatically goes into a safety mode to prevent sunlight from striking the lens.

But the Hubble was already in that position, giving controllers time to work on corrections.

The lens cover had been closed - except for a tiny wedge opening - ever since the $1.5 billion telescope was placed overboard by the Discovery crew on Wednesday. Now that it is opened, starlight can strike the lens for the first time and it can go about its business of photographing and analyzing the universe in ways and with sensitivity never before possible.

The door is made form honeycombed aluminum sheets covered on the outside with solar-reflecting material. The inside is painted black to absorb stray light.

If the door opening command had failed, the five Discovery astronauts who deployed Hubble were prepared to head back to the telescope.

by CNB