The SpaceX Dragon, having successfully berthed with the International Space Station, is on its way back home. Last week the space vehicle became the first privately-built and operated spacecraft to reach the ISS. Dragon is targeted to land in the Pacific Ocean, about 500 miles west-southwest of Los Angeles, at approximately 8:44 AM PT/11:44 AM ET tomorrow. The vehicle's return voyage, from ISS departure to splashdown, will be webcast on NASA TV starting at 3:30AM ET/12:30 AM PT.
From a NASA update:
The Expedition 31 crew of the International Space Station spent much of the day Tuesday working with the SpaceX Dragon cargo vehicle, reviewing procedures for the departure of the first commercial spacecraft to visit the station and packing it with items for return to Earth.
Dragon, which delivered 1,014 pounds of non-critical cargo on its demonstration flight to the station, was cleared unanimously Tuesday by the station’s Mission Management Team for unberthing early Thursday. In reverse order of how Dragon was captured and berthed Friday, the crew will use the station’s Canadarm2 robotic arm to detach the vehicle from the Earth-facing port of the station’s Harmony node at 4:05 a.m., move it away from the station and release it at 5:35 a.m. for return to Earth. The SpaceX team in Hawthorne, Calif., will run Dragon through about five hours of orbital operations before commanding it to a splashdown for recovery off the California coast.
After that splashdown, a ship will recover Dragon. The space vehicle will then be flown via airplane to a SpaceX site in Texas for post-flight analysis.
More on the planned activity tomorrow, from SpaceX:
The spacecraft returns to Earth like a burning comet, protected from extreme reentry temperatures by its powerful PICA-X heat shield. The landing location is controlled by firing the Draco thrusters during reentry. In a carefully timed sequence of events, dual drogue parachutes deploy at 45,000 feet to stabilize and slow the spacecraft. Full deployment of the drogues triggers the release of the main parachutes, each 116 feet in diameter, at about 10,000 feet, with the drogues detaching from the spacecraft. Main parachutes further slow the spacecraft's descent to approximately 16 to 18 feet per second.
SpaceX will use a 185-foot working barge equipped with a crane, an 80-foot crew boat, and two 25-foot rigid hull inflatable boats (RIB) to conduct recovery operations. On board will be approximately a dozen SpaceX engineers and technicians as well as a four-person dive team.
The boats will be waiting just outside of the targeted landing area. Once Dragon lands in the water, the 25-foot boats will carry the experienced dive team to the floating spacecraft. They will secure the vehicle and tow it to the barge where the crane will pick it up and place it on deck. The ships will then begin the trip back to land. In the future, Dragon will use SuperDraco thrusters to land on a landing pad on ground.
This is SpaceX's second demonstration flight under a 2006 Commercial Orbital Transportation Services (COTS) agreement with NASA to develop the capability to carry cargo to and from the International Space Station. With the first demonstration flight, in December of 2010, Dragon became the first commercial spacecraft to orbit the Earth and safely return. During that mission SpaceX conducted similar recovery operations to retrieve Dragon from a water landing in the Pacific. Demonstration missions are conducted to determine potential issues so that they might be addressed; by their very nature, they carry a significant risk. If any aspect of the mission is not successful, SpaceX will learn from the experience and try again.
Dragon Return Timeline – (times are approximate and subject to change)
Time (Pacific) Event
01:05 Dragon uninstalled using station’s robotic arm
03:10 Dragon released by the robotic arm
03:11 Dragon’s Draco thrusters fire departure burns
04:07 Unlatch/close/latch GNC door holding sensors
07:51 Dragon’s Draco thrusters fire deorbit burn
08:09 Dragon’s trunk is jettisoned
08:35 Dragon’s drogue parachutes are deployed
08:36 Dragon’s main parachutes are deployed
08:44 Dragon lands in the Pacific