Cape Canaveral, Fla. ? Shuttle Atlantis’ sick German astronaut looked and sounded well Sunday as he helped a crewmate prepare for a spacewalk that should have been his.

In an extremely unusual move, NASA pulled Hans Schlegel off the spacewalk to help install the European lab, Columbus, at the international space station, and delayed the work until today, one day later than planned.

Schlegel, 56, a physicist and former paratrooper who has seven children, was fine for Thursday’s liftoff and became ill in orbit, European Space Agency officials said, adding that the condition was neither life-threatening nor contagious.

Even though he did not look sick, spacewalks are strenuous and an astronaut needs to be in top form, they said.

The hope is that Schlegel will be well enough to take part in Wednesday’s spacewalk, the second of three planned for Atlantis’ space station visit.