NASA has powered down space shuttle Discovery for the final time, nearly three decades after it first rolled out and went on to deploy 21 satellites, including the Hubble Space Telescope, commercial spacecraft and military eavesdroppers.

The payload bay of the space shuttle was closed and locked as the spacecraft was powered off for the final time on Friday. The vehicle was “unplugged” inside Orbiter Processing Facility-1 (OPF-1) at the Kennedy Space Center in Florida.

Carried atop NASA’s modified Boeing 747 carrier aircraft, the decommissioned ship is now headed for public display at the Smithsonian National Air and Space Museum.

Technicians at the Kennedy Space Centre shut the 60-foot-long, clam-shell doors inside the orbiter as the “transition and retirement” process winds down on the most-flown shuttle.

Construction of Discovery began in August 1979 and the spacecraft was rolled out of the Palmdale factory in October 1983. It became NASA’s third operational space shuttle with its maiden voyage in August 1984.

Discovery’s rich history of service featured 39 spaceflights, spanning 148,221,675 miles and 5,830 orbits of Earth.

The spacecraft carried out both shuttle return-to-flight missions in 1988 and 2005 to help America’s space program rebound after tragedies, performed daring satellite repair missions in the early 1980’s, and deployed the Hubble Space Telescope and the Ulysses solar probe in 1990.

It had the first rendezvous with Russian space station Mir in 1995 and final joint shuttle docking in 1998, and played an integral role in building the International Space Station.