Mission accomplished -- again.
In their fourth successful space walk, the crew from the shuttle Endeavour outfitted the blurry-eyed Hubble Space Telescope today with its second pair of corrective lenses, extended the memory of its on-board computer and stowed a scientific instrument for return to Earth.
And they finished the work in 6 hours and 45 minutes.
"I'm happy . . ." astronaut Tom Akers said after installing a co-processor that will enhance the memory of Hubble's computer.
Tonight, astronauts F. Story Musgrave and Jeffrey Hoffman will attempt the last scheduled space walk to replace an electronics device that helps position the telescope's solar panels and install a backup power supply for the telescope's spectrograph. And NASA officials said they plan to boost the telescope higher into space tomorrow and unfurl Hubble's new solar panels.
The number of space walks planned for the 11-day Hubble servicing mission was unprecedented in the 12-year history of NASA's shuttle program.
"We're going for a slam dunk," Milt Heflin, the lead flight director for the mission, said this morning.
The Hubble telescope, discovered to have a focusing problem soon after its deployment in April 1990, now is equipped with two new instruments designed to correct the flaw in the observatory's primary 94.5-inch-wide mirror.
With practiced ease, astronauts Akers and Kathryn "KT" Thornton slid COSTAR (the acronym for Corrective Optics Space Telescope Axial Replacement) into the belly of the telescope, nudging the refrigerator-like component along a set of guard rails. This was no small feat as COSTAR was designed to fit snugly into the telescope and the astronauts had to be careful not to bump it for fear of disrupting the sensitive optics inside.
But the space walkers installed the package on the first try.
"Keep coming, coming . . . It's sliding in easy," Mr. Akers, an Air Force colonel, told his companion.
"It's in!" Dr. Thornton exclaimed when the job was done.
Designed in part by scientists at the Space Telescope Science Institute in Baltimore, COSTAR uses 10 mirrors -- some no bigger than a dime -- deployed on movable arms to correct the vision flaw in three astronomical instruments aboard Hubble.
The latest success mirrored that of astronauts Musgrave and Hoffman who yesterday replaced the telescope's Wide-Field Planetary Camera with an improved model. The camera, which accounts for half of Hubble's scientific observations, had been outfitted with new optics to compensate for Hubble's misshapen primary mirror.
