NASA's space shuttle Atlantis today is spending what is expected to be its final day in space. The six person crew of Atlantis craft's has been testing the shuttle's flight control system and maneuvering jets today in preparation for a scheduled 8:48 a.m. EDT landing at Kennedy Space Center in Florida.

At this point, NASA plans to immediately retire Atlantis and then the remainder of the shuttle fleet after two other spacecraft complete their final missions. Some observers expect that delays will force the NASA space shuttle program to continue into next year.

After undocking from the International Space Station, the shuttle crew made a customary fly around the station to check for any anomalies or damage to the orbiter. Then on Monday, the crew did a final inspection of the shuttle's heat shields, using cameras mounted on the robotic arm of Atlantis.

Over the course of the latest mission to the space station, astronauts installed a Russian-made module , which will add storage space, and room for scientific research to be done. The astronauts also installed a communications dish antenna on the outside of the station. And one of their last tasks was to install six new batteries on the space station's solar array.

The Atlantis lifted off from Kennedy Space Center in Florida on May 14. The space shuttle has been flying for 25 years and had logged in 115 million miles before this latest mission began.

The last space shuttle flights are focused on ferrying spare parts and equipment to the space station. Once NASA's shuttle fleet is retired, it will be far more difficult, if not impossible, to get such massive pieces of equipment to the station.