The last US space shuttle departed the International Space Station today, ending a 12-year program to build and service the orbital outpost, the primary legacy of Nasa's shuttle fleet.
Shuttle Atlantis commander Chris Ferguson and pilot Doug Hurley gently pulsed their spaceship's steering jets at 06:28 GMT to pull away from the station as they sailed about 250 miles over the Pacific Ocean.
"Thanks so much for hosting us," Ferguson radioed to the station crew. "It's been an absolute pleasure."
"We'll miss you guys," replied station flight engineer Ron Garan. "See you back on Earth."
Flight controllers at Nasa's Mission Control Center sat in reverent silence as they watched the last shuttle pulling away from the station, a $100 billion project of 16 countries that has been assembled and serviced during 37 of Nasa's 135 shuttle missions.
During their nine-day visit to the station, Ferguson and his crew delivered more than 5 tons of food, clothing, equipment and science experiments, a stockpile intended to bridge a potential year-long gap in US cargo runs to the station.
Atlantis' return to Earth, scheduled for Thursday, will conclude the 30-year-old US space shuttle program, with no replacement US spaceships ready to fly.
Nasa has hired two private firms, Space Exploration Technologies and Orbital Sciences Corp., to resupply the station beginning next year. Russia, Europe and Japan also fly freighters to the station.
Astronauts will fly aboard Russian Soyuz capsules at a cost of more than $50 million per person, until and unless US companies are able to offer similar transportation services. Several firms, including Boeing, Space Exploration Technologies and Sierra Nevada Corp. are developing passenger spaceships, but none are expected to be ready until about 2015.
The first US space taxi to reach the station will return home with a prize. In an emotional farewell ceremony Monday, Ferguson presented the station crew with a small American flag that flew during the April 1981 debut flight of sistership Columbia.
The flag was mounted on the vestibule wall of the compartment that leads to the shuttle's now-obsolete docking port. It is promised to the first US company that flies astronauts to the station.
Nasa wants to refly the flag aboard the first of its planned spaceships that are designed to carry astronauts to asteroids, the moon and other destinations beyond the station, where the shuttles cannot go.
Atlantis is due back at the Kennedy Space Center at 11:57 GMT Thursday.