The Hubble Space Telescope orbited with its big eye open Friday after ground controllers overcame communications problems and lifted its lens cover, but its electronics were shut down due to a malfunction. Those problems, however, were not the immediate concern of shuttle Discovery's astronauts, who prepared for Sunday's return to Earth. ``You've been released from Hubble support. It's on its own,'' Mission Control's Story Musgrave told the five crew members. ``That's great news,'' replied Discovery commander Loren J. Shriver. ``There are handshakes and smiles all around up here. I'll bet it's just that way back down there, too,'' added mission specialist Steven Hawley. ``Who's buying tonight?'' ``We'll buy when you all get back,'' Musgrave replied. Flight director William Reeves said it was too early to cheer. `We still have an important part of the mission to go,'' Reeves said. ``We reserve our celebration until the crew is safely on the ground.'' Discovery is to land at 9:48 a.m. EDT Sunday at Edwards Air Force Base, Calif. Landing would have been delayed a day if astronauts Bruce McCandless and Kathryn Sullivan had had to perform a space walk to crank open the telescope's lens cover, or aperture door. The shuttle trailed 50 miles behind Hubble when the aperture door opened 380 miles above Earth, but passed 3.7 miles beneath the telescope later in the day. The National Aeronautics and Space Administration had planned to release its first test image from the $1.5 billion telescope on Tuesday, showing an open star cluster in the constellation Carina. But Steve Terry, director of orbital verifications, said that would be delayed by problems with Hubble's high-speed antennas. Scientific data will follow in a month or two. Hubble's 10-foot aluminum aperture door was opened to the heavens at 10:30 a.m. EDT, nearly four hours later than planned, exposing its finely polished 94.5-inch mirror to starlight for the first time. Ground controllers sent a signal commanding the door to lift even though the telescope was in an automatic ``safe mode,'' with all motion stopped because of problems in linking its high-speed dish antennas with a relay satellite. One of the two antennas apparently had swung too far, and the telescope shut down, said Jean Oliver, a Hubble deputy project manager. If future movements of the antenna have to be limited to avoid the problem, it would have only slight impact on the telescope's observing time, Oliver said. Terry said the opening of the aperture door could not have been delayed much longer. ``There has to be a point where you say they have to go their way and we have to go ours,'' he said of the astronauts. When the door opened, two of Hubble's four position-stabilizing gyroscopes stopped working; later, engineers got them back on line. The motion of the lens cover knocked out the gyros, said Dave Drachlis of the Goddard Space Flight Center in Maryland. That, too, kept it in the safe mode. Oliver said it would be Saturday morning before the telescope is brought out of the safe mode. It will take another day to get the instrument operating normally again, putting controllers at Goddard several days behind. ``We're trying to be very deliberate and trying not to cut any corners and do anything fast because we feel there's a lot at risk here and we want to make sure we're doing it properly,'' Oliver said. ``We've got a long future ahead of us, and we want to make sure it starts off on the right foot.'' NASA said the telescope was safe and in a stable position. Tolerances for the telescope systems were set particularly narrow for the first operations and that was the cause of many malfunctions, Terry said. In addition to that trouble, there were two communications outages totaling several hours. ``We're cautious, and that's natural,'' Terry said. ``We've got a very expensive spacecraft here and we don't want to do anything to jeopardize the usefulness. ... We'll get to the point where we know exactly what the spacecraft will do and set the limits appropriately.'' Terry said Hubble is designed with safe modes so it can be ``the master of its own destiny'' in case contact with an orbiting communications system is lost for extended periods. The telescope will share the system, known as Tracking and Data Relay Satellites, with other space craft. Except for a tiny wedge opening, the lens cover had been closed and the telescope blind ever since Hubble was released by the astronauts Wednesday. From its orbit high above Earth's distorting atmosphere, the telescope will enable astronomers over its 15-year working lifetime to look back 14 billion years and possibly determine the age of the universe. The universe is believed to have been created about 15 billion years ago in a cosmic explosion. The late astronomer Edwin P. Hubble, for whom the telescope is named, provided the basis for the Big Bang theory of creation. He discovered during the 1920s that the universe is expanding and that the farther the galaxy is from Earth, the faster it is moving away. In honor of the astronomer, Sullivan carried with her into space an eyepiece from the 100-inch telescope at California's Mount Wilson Observatory that Hubble used to make his pioneering observations. ``It's a great pleasure to have something of such historical significance and something that so directly symbolizes Edwin Hubble's fundamental contributions to astronomy,'' she said Friday afternoon. Once back on Earth, the eyepiece will be displayed at the observatory.
