A key test of a daring yet wobbly spacewalking technique that could be used someday to repair space shuttle heat shields worked well yesterday and got good reviews from two astronauts from the shuttle Discovery, which probably won’t need quick fixes, Nasa officials said.

Space shuttle Discovery escaped damage from the potentially deadly chunk of foam that broke off from the fuel tank during lift-off, but may have been struck in the wing by a much smaller piece, Nasa says.