sm-shuttle-endeavour-220-nasa

NASA typically does not allow unmanned cargo ships to dock while one of its space shuttles is still at the International Space Station. ((NASA))

The last flight of the space shuttle Endeavour has been pushed back 10 days.

NASA announced Monday that it has rescheduled the launch for 3:47 p.m. ET on April 29.

The 14-day mission, officially known as STS-134, had been scheduled to blast off on April 19.

However, that would have resulted in a scheduling conflict with the unmanned Russian Progress supply vehicle scheduled to launch April 27 and arrive at the International Space Station April 29 — while the space shuttle would have still been at the station, NASA said.

The new launch date, set following a meeting of International Space Station partners on Sunday, eliminates that conflict.

NASA spokesman Kyle Herring said typically the space agency does not allow unmanned cargo vehicles to dock while a space shuttle is at the station because the docking process, including the firing of the cargo ship's thrusters near the station, poses some risk to the shuttle.