Mission Crew 11 returned early due to medical problem: first time in 25 years

"The early return of some 20 days does not compromise the mission and does not change much in the organisation of work on the ISS," noted Paolo Nespoli, space veteran who has three missions for the European Space Agency to his credit. "Probably the decision to anticipate the re-entry was dictated by a precautionary choice."

Nasa gave notice of a crew member's health problem on 7 January, at the same time announcing the postponement of the spacewalk scheduled for the following day. The two Nasa astronauts Zena Cardman and Mike Fincke were supposed to take it.

It is plausible that the health problem was detected in the medical examination that is used to give clearance for extra-vehicular activity, but of course there is absolute secrecy about both the nature of the health problem and the astronaut in whom it was detected.

Nasa merely said that conditions are stable. 

On the Iss, "most medical problems can be solved, as they have been in the past, without aborting the mission," Nespoli said. "In 25 years this is the first time a space mission has been aborted for medical reasons. Usually these problems are solved on board through coordination between astronauts with medical training and under the guidance of doctors from the mission's ground control centre, in a kind of telemedicine," added the former astronaut, who had received training in dealing with medical problems on his missions.

"There is also a well-stocked pharmacy on the International Space Station, including medicines that American astronauts call 'controlled' because their use must be authorised by the doctor on Earth, in a kind of prescription," he said.

Since it was not considered an emergency, normal procedures were followed: the shuttle Endeavour ditched in the Pacific Ocean off the coast of California and, after recovery by ship, the crew had to be transported to the mainland by helicopter and then by plane to NASA's Johnson Space Center.

"This is the first time we are performing a controlled medical evacuation from the vehicle," said Amit Kshatriya, Nasa's associate administrator. "What matters to us," he added, "is the entire crew and we don't want to do anything, given the nature of the condition, that would pose additional risk to the crew by deviating from our normal procedures."