NASA and SpaceX’s historic first manned space mission, which has been operating almost flawlessly since launch, has come to an end. The return of two astronauts to earth in the SpaceX capsule marks the end of a two month historic mission, which once again gives the United States the ability to send its astronauts into space, something that has been lacking since the shuttle fleet retired.

the crew dragon spacecraft used in the mission, named dragon endeavor, will return from the international space station on Saturday.

since leaving the international space station on Saturday, the spacecraft has carried out a series of engine combustion for a total of 11 minutes and 30 seconds to lower its orbital altitude. It enters the earth’s atmosphere at about 2:42 Beijing time on August 3. When “crew dragon” descends in the atmosphere, it will start to heat up, and the outer thermal shield of the capsule will protect the spacecraft and its crew. Due to the heating plasma accumulated around the capsule, the communication signal will be disturbed, followed by a difficult six minute communication silence period.

the atmosphere helps cushion the fall of “crew dragon”, which greatly slows down its speed. But the spacecraft needs a little extra help to get down safely. At about 18000 feet, two parachutes will be deployed from the spacecraft as the capsule moves at 350 miles per hour. These small parachutes will slow the capsule down to about 119 mph before the main one is deployed. When “crew dragon” is lowered to 6000 feet, four large red and white parachutes will be deployed to brake the aircraft and make it slowly splash into the sea.

tropical storm Isaias is currently circling in the Gulf of Mexico, generating enough wind speed to damage roofs and buildings. There are several potential splash sites in this bay, including four in the Gulf of Mexico west of Florida. Mission planners said the wind speed and wave height were low enough for crew dragon to land safely in these areas.

the safe return of crew dragon to earth means that NASA will officially certify the spacecraft to be manned. An atypical feature of this mission is that astronauts bainken and Hurley will fly up on crew dragon and return in the same boat. Normally, the capsule will transport one group of astronauts to the space station and then return with another.