The space shuttle Discovery undocked from the International Space Station on Saturday and headed home after a mission to install a new ammonia tank and deliver experiments and other gear.
The Discovery astronauts completed three spacewalks to install the ammonia tank to the station's cooling system. But a problem with a stuck valve needed to get the tank operating caused problems and NASA briefly considered adding a fourth spacewalk to fix it.
The space agency eventually decided the tank could operate as it is temporarily and that the problem can be solved later without another spacewalk on this mission.
Last week NASA extended Discovery's mission by one day to allow the crew to inspect the shuttle's heat shield while still docked at the ISS. The inspection found no problems with the shuttle.
Discovery is now slated to land at Kennedy Space Centre in Florida Monday at 8:54 am (1824 IST).
The US space agency is scheduled to retire the ageing space shuttle fleet later this year after three remaining missions.