The space shuttle Discovery undocked from the International Space Station for the last time this morning and started its two-day journey back to the Kennedy Space Center.
The shuttle fired its jets to separate from the ISS at 8:37am Eastern, NASA said. Discovery is scheduled to land at 11:58am on Wednesday; at this point, weather conditions are favorable.
Overall, the astronauts engaged in seven days, 23 hours, and 55 minutes worth of joint activities with the ISS crew. This is Discovery's 39th and final mission.
The crew received a special wake-up call at 3:23am this morning: the theme from "Star Trek" and a recorded message from actor William Shatner. "Space, the final frontier. These have been the voyages of the Space Shuttle Discovery. Her 30 year mission: To seek out new science. To build new outposts. To bring nations together on the final frontier. To boldly go, and do, what no spacecraft has done before," Shatner said.