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| Rendezvous and Docking Overview |
| Overview |
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Rendezvous and Docking Endeavour's rendezvous and docking with the International Space Station begins with the precisely timed launch of the shuttle on a course for the station. During the first two days of the mission, periodic engine firings will gradually bring Endeavour to a point about 9 ½ statute miles behind the station, the starting point for a final approach to the station. About 2 ½ hours before the scheduled docking time on Flight Day Three, Endeavour will reach a point about 50,000 feet behind the ISS. At that time, Endeavour's jets will be fired in a Terminal Intercept (TI) burn to begin the final phase of the rendezvous. Endeavour will close the final miles to the station during the next orbit. As Endeavour closes in, the shuttle's rendezvous radar system will begin tracking the station and providing range and closing rate information to the crew. During the approach toward the station, the shuttle will have an opportunity to conduct four small mid-course corrections at regular intervals. Just after the fourth correction is completed, Endeavour will reach a point about half a mile below the station. At that time, about an hour before the scheduled docking, Commander Kent Rominger will take over manual control of the approach. Rominger will slow Endeavour's approach and fly to a point about 600 feet directly below the station, from which he will begin a quarter-circle of the station, slowly moving to a position in front of the complex, in line with its direction of travel. Rominger will be assisted by Pilot Jeff Ashby in controlling Endeavour's approach. Mission Specialists Chris Hadfield and Scott Parazynski also will play key roles in the rendezvous, with Parazynski helping with the rendezvous navigation and Hadfield operating a handheld laser-ranging device. Hadfield and Parazynski also will operate the shuttle's docking mechanism to latch the station and Endevour together after the two spacecraft make contact. Rominger will fly the quarter-circle of the station, starting 600 feet below it, while slowly closing in on the complex, stopping at a point a little more than 300 feet directly in front of the station. From that point, he will begin slowly closing in on the station - moving at a speed of about a tenth of a mile per hour. Using a view from a camera mounted in the center of Endeavour's docking mechanism as a key alignment aid, Rominger will precisely center the docking ports of the two spacecraft. Rominger will fly to a point where the docking mechanisms are 30 feet apart, and pause for about five minutes to check the alignment. For Endeavour's docking, Rominger will maintain the shuttle's speed relative to the station at about one-tenth of a foot per second, and keep the docking mechanisms aligned to within three inches of one another. When Endeavour makes contact with the station, preliminary latches will automatically attach the two spacecraft together. Immediately after Endeavour docks, the shuttle's steering jets will be deactivated to reduce the forces acting at the docking interface. Shock absorber-type springs in the docking mechanism will dampen any relative motion between the shuttle and the station. Once relative motion between the spacecraft has been stopped, Hadfield and Parazynski will secure the docking mechanism, sending commands for Endeavour to retract and close a final set of latches between the shuttle and station. Undocking, Separation and Flyaround Once Endeavour is ready to undock, Hadfield and Parazynski will send a command that will release the docking mechanism. The initial separation of the spacecraft will be performed by springs in the docking mechanism that will gently push the shuttle away from the station. Endeavour's steering jets will be shut off to avoid any inadvertent firings during this initial separation. Once the docking mechanism's springs have pushed Endeavour away to a distance of about two feet, when the docking devices will be clear of one another, Ashby will turn the steering jets back on and fire them to begin very slowly moving away. From the aft flight deck, Ashby will manually control Endeavour within a tight corridor as he separates from the ISS, essentially the reverse of the task performed by Rominger when Endeavour docked. Endeavour will continue away to a distance of about 450 feet, where Ashby will begin a close flyaround of the station, making almost three-fourths of a circle around it. During the flyaround if available propellant permits, Ashby will slightly angle Endeavour to allow an IMAX film camera in the payload bay to record scenes of the station with the Earth below. Ashby will pass directly above the station, then behind, then directly underneath it. At that point, Ashby will fire Endeavour's jets for final separation from the station. The flyaround is expected to be completed a little over an hour after undocking. |
Editorial/Technical Comments: ShuttlePresskit
