NASA was contemplating a fourth spacewalk, to prevent another potential hazard during Discovery's return to Earth. Shortly after astronaut Steve Robinson finished removing two pieces of "gap filler" from the shuttle's insulating tiles, NASA engineers thought the crew needed to do another spacewalk.
The new concern: a torn thermal blanket below a cockpit window. The thermal blanket protects the shuttle from extreme temperatures encountered during space flight. NASA was worried that, during the shuttle's re-entry, a roughly 300 millimeter-long section of the blanket could tear away, turn around and slam into the shuttle, possibly causing severe damage.
Thursday, Shuttle Commander Eileen Collins said she was not worried about her crew's safe return, which is set for Monday. "I feel very confident coming back because we have looked at everything and whatever we decide to do on the blanket, I'm not too worried about it. I think it's going to be fine, and I am really looking forward to getting back and seeing my family again."
Also Thursday, the nine shuttle crewmembers took time to remember the crew of the Space Shuttle Columbia, and other fallen astronauts and cosmonauts. Each Discovery astronaut read a tribute, transmitted back to Mission Control. "To the crew of Columbia, as well as the crews of Challenger, Apollo One, and Soyuz One and Eleven, and to those who have courageously given so much, we now offer our enduring thanks. From you, we will carry the human spirit out into space, and we will continue the explorations you have begun."
The Columbia and Challenger shuttles broke up in the Earth's atmosphere, Apollo One burned on the launch pad, and the crews of Soyuz One and Eleven died in landings.