The space shuttle Atlantis is making final preparations for its last return to earth, marking the end of the 30-year U.S. space shuttle program.

NASA says the four astronauts on board Atlantis shut the payload doors and began de-orbiting procedures on Thursday. The shuttle is scheduled to touch down at the Kennedy Space Center in the southern state of Florida at 9:56 UTC.

Officials say the weather forecast continues to be “very favorable” for the landing.

On Wednesday, mission managers completed final inspections of the shuttle's heat shield for entry into the Earth's atmosphere. Atlantis also deployed a four-kilogram satellite, the last to be released by a U.S. space shuttle.

Atlantis' 13-day mission capped off its 33rd and final flight after 26 years in service.

The crew departed from the International Space Station on Tuesday after an eight-day visit to deliver a year's worth of supplies, and haul trash and used equipment back to Earth.

Atlantis will be displayed at the Kennedy Space Center after its retirement.