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| Rendezvous and Docking Overview |
| Overview |
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Atlantis’ rendezvous with the International Space Station actually begins with its precisely timed launch from the Kennedy Space Center in Florida. The shuttle will rendezvous with the station either on Flight Day 3 or 4, based on the time and date of launch, and at a time based on ISS-orbiter phasing. The primary pre-rendezvous activities include a check-out of the orbiter's remote manipulator system, or robot arm, (RMS), the extravehicular mobility units (EMUs) or spacesuits, the Ku-band antenna, the orbiter docking system (ODS), and the ground command system. The final phase of rendezvous operations begins about three hours prior to Atlantis’ docking with the ISS. Atlantis will approach the ISS from below, in what is referred to as a plus-R bar approach, to minimize the effects of jet thruster firings on the station and its solar arrays. About 40 minutes before the terminal initiation burn (Ti burn) when Atlantis moves within 135,000 feet of the station, the shuttle’s rendezvous radar system is activated to provide supplemental navigation information. Prior to initiating the Ti burn, the crew will power on the ODS and activate Atlantis’s docking lights. A series of course correction burns will bring Atlantis to a point almost directly below and behind the station, at which point Commander Ken Cockrell initiates the manual portion of his approach to the ISS. Atlantis will intercept the R-bar about 700 feet below the station. Cockrell will slowly move Atlantis to a point about 600 feet below the station before performing a 180 degree yaw maneuver to position Atlantis in a “tail forward” attitude for the final approach and docking. As Cockrell gently moves Atlantis toward the station, the shuttle will stationkeep at distances of 170 feet and 30 feet before initiating the final approach and docking. Solar arrays on the Zarya and Zvezda modules and the recently-installed P6 solar arrays will be feathered and locked at a predetermined angle, to limit the induced loads from shuttle thruster firings. Atlantis will dock with Pressurized Mating Adapter (PMA) 3 on the downward-facing port of the Unity module. At initial contact and capture, the ISS and Atlantis will go to free drift to avoid imposing excessive loads on the orbiter docking system (ODS). After capture, light-emitting diodes on PMA-3 will blink confirming the ISS is in free drift. The crew will be able to see the red indicators through the overhead window on Atlantis’s aft flight deck and verify that the ISS is in the free-drift mode before beginning the automatic rigidization and retraction process and closure of the capture latches between the two docking hatches. Once a “hard dock” is confirmed, the ODS will be deactivated, solar arrays will resume sun tracking, and the Atlantis-ISS complex will maneuver to the mated attitude. Docked Operations Hatches between Atlantis and the ISS will open about two hours after docking to allow the Expedition One and STS-98 crews to greet one another. After the greeting and some initial cargo transfer, the hatches will be closed and Atlantis’ cabin pressure will be lowered in preparation for the space walks, which will begin the next day. Throughout a week of docked operations, the hatches will be opened and closed to support the transfer of supplies and three scheduled space walks to outfit the Destiny laboratory module. On Flight Days 4, 6 and 8, Astronauts Tom Jones and Robert Curbeam will conduct space walks to relocate one docking port, attach the Destiny module and connect power cables; remove thermal coverings and hatch pins that were installed for launch; and relocate a spare S-band antenna assembly. The astronauts also will transfer equipment and supplies to the space station and outfit the Destiny laboratory for future use. Departure Atlantis is scheduled to undock from the ISS on Flight Day 10. In preparation for the undocking the STS-98 crew will once again power-up the orbiter docking system, turn on the shuttle docking lights, terminate all OIU operations, and enable the shuttle’s navigational aids. Following its undocking, Pilot Mark Polansky will slowly back Atlantis away from the ISS at the rate of about 1/10 of a foot-per-second before beginning a flyaround. Atlantis will move to a point about 450 feet below the station before beginning a tail-forward circuit of the station, arriving once again at a position approximately 450 feet below the station. At that point, Polansky will perform a final separation burn to move Atlantis away from the station. Once Atlantis is about 30 feet away from the station, the Expedition One crew will activate the station’s attitude control systems. The Zvezda module will then maneuver station to its normal orientation for orbital operations, the solar arrays will be commanded to resume sun tracking, and the station docking system and lights will be deactivated. |
Editorial/Technical Comments: ShuttlePresskit
