The journey marked the first use of a space shuttle since the Columbia disaster in February 2003. Discovery's mission, besides bringing supplies to the space station and restoring full steering capability to the orbiting outpost, included testing various new safety features and procedures of the shuttle program.
More than 100 cameras on the shuttle and on the ground documented the July 26 launch of the spacecraft and recorded a large piece of foam flying off the external fuel tank, barely missing the orbiter. In response, NASA grounded future shuttles until the insulation problem can be fixed.
Sept. 22 was the tentative launch date for the next shuttle, Atlantis, but NASA now calls that timeframe unrealistic, Reuters reported.
Robotic arms with laser tips traced 3-D images of Discovery's underbelly while in orbit, and astronaut Stephen Robinson completed a spacewalk to remove two protruding and potentially hazardous filler strips from between the tiles.
Discovery's landing was postponed a day due to cloudy weather over Cape Canaveral, Fla. Continued thunderstorms in Florida shifted the landing site to California in the predawn hours Tuesday.
"Congratulations on a truly spectacular test flight," Mission Control told Discovery after it glided to a landing. "Welcome home, friends."
"We're happy to be back and we congratulate the whole team for a job well done," Commander Eileen Collins replied.
Two-and-a-half years ago, Columbia broke apart during re-entry after the insulating foam punched a hole in the wing, allowing superhot gasses generated during re-entry to bleed through the heat shield. All seven astronauts on board perished.
No problems were immediately reported during Discovery's landing, according to the Associated Press.
Two hours after touchdown, the astronauts walked around the spacecraft to inspect for possible damage.
"It looks fantastic," Collins said of the shuttle's condition, reported the AP.
Now, NASA will need to transport the shuttle back to Florida at an estimated cost of $1 million.
The astronauts -- Collins, Robinson, Charles Camarda, James Kelly, Wendy Lawrence, Soichi Noguchi and Andrew Thomas -- and their families, who had gathered in Florida at the original landing site, will reunite on Wednesday in Houston.