Astronauts snare Hubble, repair flaws.

A team of specialists paid a call on the ailing Hubble Space Telescope this week, hoping their ministrations would sharpen the telescope's cloudy vision and improve its overall health. Featuring an unprecedented series of space walks, the mission began after a two-day chase in which the space shuttle Endeavour came within 30 feet of Hubble. Astronaut Claude Nicollier, using a mechanical arm, reached out, grabbed the orbiting observatory, and secured Hubble in the shuttle's cargo bay

"Houston, Endeavour has a firm handshake with Mr. Hubble's telescope," radioed shuttle commander Richard O. Covey

Although Hubble's blurry vision has become the telescope's most notorious flaw, astronauts addressed other problems during the mission's first two space walks (SN: H/6/93, p. 296). Floating out into the cargo bay for the first walk, Jeffrey Hoffman and Story Musgrave replaced two pairs of gyroscopes (top photo), three of which had failed. Had a fourth gyroscope died before the repair, Hubble could no longer have pointed accurately enough to observe astronomical targets.

During the second walk, Kathryn Thornton and Tom Akers replaced Hubble's two wing-like solar arrays, which flapped unacceptably each time the telescope passed in and out of Earth's shadow. Ground controllers had earlier commanded the arrays to roll up like window shades so the crew could stow them for a return trip to Earth. But one of the 400-pound, 5-meter arrays, badly warped during its 3.5 years in space, retracted only partially, making it impossible to store. Thornton first attached a handle to the warped array as she perched on the end of the mechanical arm. She then jettisoned the array, which drifted into space (bottom photo) as the shuttle gently sped away

It will take some seven weeks to determine whether the crew's optical repairs have improved Hubble's ability to see faint objects.