American replaces German Astronaut on Spacewalk due to Medical Issues

Astronauts at the International Space Station will conduct a spacewalk on Monday to install the Columbus Space Laboratory. The task will be performed by Americans Rex Walheim and Stan Love after German astronaut Hans Schlegel pulled out owing to medical issues.

"Yesterday there were readings which called for caution," DLR official Andreas Schuetz said about Schlegel's health problems. He probably suffered an attack of space adaptation sickness but is likely to make the mission's second spacewalk on Wednesday.

"Today it has turned out that he is in perfect form and there is nothing standing in the way of the second spacewalk,” Schuetz said.

Schlegel, 56, was scheduled to perform the first two of three spacewalks with veteran spacewalker Rex Walheim. After discussions with the crew, flight surgeons postponed the first spacewalk by 24 hours and changed the lineup.

NASA officials did not discuss the Schlegel’s illness, citing medical privacy policies. This morning, however, a European flight director wished him a quick recovery.

Schlegel is scheduled to join Walheim for the second spacewalk to continue the external setup of Columbus, said John Shannon, NASA's mission management team chairman.

A third spacewalk will then be carried out by Walheim and Love on Friday, to attach a pair of science instruments to Columbus.

The mission has been delayed by a day as the first space walk, which was meant to start the work of attaching the European Space Agency's (ESA) Columbus module to the ISS had originally been set for Sunday.

Consequently, space shuttle Atlantis will also be delayed in returning to Earth and will reach back on February 19 instead of the previously scheduled February 18.

The Atlantis, carrying a crew of seven, docked with the ISS on Saturday. The space shuttle is on the mission in which the key task is affixing the Columbus space lab module to the orbiting ISS.

Besides Schlegel's health, NASA faced two more problems. One involved a flight computer failure, but Shuttle flight director Mike Sarafin said there were two other such computers on board.

Another problem was the small split in the thermal blanket on the right Orbital Maneuvering System pod. NASA said that ‘focused inspections’ of the shuttle's thermal protection system will be performed.