NASA has swapped out the next crew headed for the International Space Station. Astronaut Michael Fincke and cosmonaut Gennady Padalka will be replacing Russian Valery Tokarev and American Leroy Chiao. Russian space officials said that it wasn't because the team was unprofessional or ill, just that it hadn't had enough time to be ready for space - Leroy Chiao was only added to the team last month when astronaut William McArthur fell ill. Fincke and Padalka are due to blast off on from the Baikonur cosmodrome with Dutchman Andre Kuipers in a Soyuz rocket on April 19.