NASA invented a device to improve the telescope's optics. The new device is called COSTAR (Corrective Optics Space Telescope Axial Replacement). They would place two concave primary mirrors to reflect light properly to the new Wide Field Planetary Camera 2 and four axial instruments. This would be the hardest repair to the Hubble Space Telescope.
It's tricky operating in the weightless environment of space, wearing a bulky space suit, and working with delicate parts and instruments. Endeavor astronauts had over 100 training sessions. They practiced controlling the remote manipulator arm they would stand on to complete the repairs. It took 394 hours in water tanks to practice replacing the second Wide Field Planetary Camera and installing COSTAR. They worked five days during the 11 day mission on up to six hour shifts, establishing a new American record for their five space walks.
Photo. Astronaut K. Thornton works in NASA's Weightless Environment Training Facility (WETF) to practice replacing the Wide Field Planetary Camera. Courtesy NASA.
Future improvements to the Hubble Space Telescope are in the works. NASA wants to install an infrared camera, replace Wide Field Planetary Camera 2, and add other new devices on the telescope. Three additional repair missions have been planned.
Photo, left. The view from a flawed Hubble, seen through the Wide Field Planetary Camera 1.
Photo, right. With the new COSTAR system, the view from Hubble's new Wide Field Planetary Camera 2 is now much clearer; the telescope can also pick up objects much more distant.
Both courtesy STSCI, NASA.
The Hubble Space Telescope has been fixed so it will see more clearly now. WFPC1 could only see light from 3 - 4 billion light years away but its replacement, WFPC2, can see 11 - 12 billion light years distant. Since HST has been repaired, it has witnessed spectacular events taking place in our own solar system and viewed distant objects that can give us clues to the age and size of the universe.
HST has opened a new window to the universe. We have the ability to look across the vastness of space back in time perhaps to the origin of the universe.