A new kind of insulation and adhesive were used on the Discovery to produce a stronger bond, a NASA spokeswoman said.

A NASA spokeswoman said last night that Mr. Cooper was survived by his wife but that she had no further information on survivors.

"Everything worked out great," said Susan Hendrix, a NASA spokeswoman.

"At this point, we know we are not going to use the component," said Sara Keegan, a NASA spokeswoman.

The center will be closed through Monday at least, said a NASA spokeswoman, Melissa Mathews.

Nancy Lovato, a NASA spokeswoman at Edwards, said, "It was an apparently perfect landing."

Sarah Keegan, a NASA spokeswoman, said lens of the null corrector was too far from a mirror.

"The difficulty with patches is being able to find a material that's suitable," said Ms. Motichek, the NASA spokeswoman.

"It's something we're not prepared to look at right now," said Peggy C. Wilhide, a NASA spokeswoman.

Sarah Keegan, a NASA spokeswoman, said in an interview that a comparative figure for the defunct space station Freedom was $14.6 billion.