Endeavour is slated to land Friday at Florida's Kennedy Space Center following a two week return voyage to the International Space Station.
NASA said one of two thrusters used to control Endeavour following its de-orbit burn failed Thursday morning's test. The space agency, however, said the jet's failure "will not be an issue for landing." It provided no further details.
The crew also tested Endeavour's aerospace surfaces and flight control systems. NASA did not report any problems with those systems.
Endeavour crewmembers on Wednesday inspected the craft's heat shield to ensure it can withstand reentry. NASA again reported no issues. The shield already passed one inspection, but NASA wanted to be certain that the shuttle's protective tiling was not seriously damaged by liftoff debris when it blasted off on July 15.
NASA also wanted to ensure the heat shield was not damaged in space.
Pieces of foam insulation from the external fuel tank damaged heat shields on the space shuttle Columbia in 2003. The vehicle disintegrated upon reentry to Earth's atmosphere, killing all seven astronauts aboard.
The seven space shuttle Endeavour crewmembers said their goodbyes to counterparts aboard the ISS early Tuesday as the shuttle undocked from the orbiting research platform. On Monday, a pair of astronauts from Endeavour worked their way through a five hour spacewalk around the ISS. The jaunt saw them complete a range of maintenance and research tasks outside the station.
Endeavour lifted off on July 15th after a series of delays caused by faulty equipment and bad weather.
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