|Mission name||Soyuz TMA-18
|Call sign||утес ("cliff")|
|Launch pad||Baikonur Cosmodrome Site 1/5|
|Launch date||2 April 2010
|Landing||25 September 2010
|From left to right: Caldwell Dyson, Skvortsov and Korniyenko|
|Flight Engineer 1||Mikhail Korniyenko
|Flight Engineer 2||Tracy Caldwell Dyson, NASA
Backup crew 
|Flight Engineer 1||Andrei Borisenko|
|Flight Engineer 2||Scott Kelly, NASA|
After a successful launch on 2 April 2010, the Soyuz TMA-18 spacecraft transported cosmonauts Alexander Svortsov, Mikhail Kornienko and NASA astronaut Tracy Caldwell Dyson of the Expedition 23/24 crew to the International Space Station (ISS). Spacecraft commander Skvortsov occupied the center seat of the Soyuz TMA-18 with Kornienko on his left and Caldwell Dyson on the right. The launch was perfect and the flight only experienced communications difficulties shortly after launch. The communication problem made it impossible for the Russian mission control officials to communicate with the crew until after they reached the preliminary orbit. However, a live on-board television camera clearly showed the crew was safe. After 9 minutes, the Soyuz spacecraft settled into a preliminary orbit of 143 miles by 118 miles. It also deployed antennas and solar arrays for power generation. The spacecraft spent the following two days orbiting the Earth gradually closing in on the ISS.
Soyuz processing 
Prior to the launch systems testing and integration of the rocket and spacecraft had been underway for several months. In February 2010 specialists at the RSC-Energia and Yuzhny Space Center tested the Kurs docking support system and onboard computer of the Soyuz reentry capsule. Autonomous tests of the Soyuz TMA-18 crew vehicle systems were also successfully completed at the Baikonur Cosmodrome and the integrated tests of the rocket commenced at site 254. Filling station (site 31) was prepared for further tanking of the Soyuz propulsion system by propellant components ad pressurized gases. In early March, containment tests on Soyuz TMA-18 were carried out at the vacuum chamber facility. Specialists from the TSKB-Progress in Samara and Yuzhny Space Center started assembling and testing of the Soyuz-FG rocket. Integration of the second stage and pneumatic tests of the first stage's units were performed on 16 March.
The Soyuz TMA-18 primary and backup crews arrived at the Baikonur Cosmodrome on 21 March. They arrived in two Tu-134 air planes. The Soyuz tanking was completed on 23 March and the spacecraft was returned to site 254, to proceed with further prelaunch operations.
On 31 March the Soyuz FG rocket carrying the Soyuz TMA-18 spacecraft was rolled out from the integration and test facility and was erected at launch pad 1.
On 4 April 2010, three minutes ahead of schedule, Soyuz TMA-18 successfully docked to the Poisk module on the ISS at 5:25 UTC. Shortly after the initial contact automatic closing of Soyuz & MRM2 port hooks and latches took place while the space station was in free drift. As part of docking preparations, earlier attitude control authority had been handed over to the Russian Motion Control System at approximately 3:10 UTC. The control was returned to US CMG control at approximately 6:50 UTC. For the docking, the Russian thrusters were disabled during Soyuz volume pressurization and clamp installation and after wards returned to active attitude control. Before hatch opening, the crew performed leak checks of the Soyuz modules and the Soyuz/MRM2 interface vestibule. They then removed their Sokol suits, and Kornienko set them and their gloves up for drying. Skvortsov deactivated the BOA/Atmosphere Purification Unit in the SA/Descent Module, replaced the Soyuz ECLSS LiOH cartridges, equalized Soyuz/ISS pressures, and put the spacecraft into conservation mode on ISS integrated power.
After about 1 hour 45 minutes spent in Soyuz on pre-transfer activities, hatches were opened at 7:21 UTC and the crew transferred to the ISS. A welcome ceremony for the new arrivals followed hatch opening with family members and dignitaries participating from the Russian mission control center in Korolev. Skvortsov also installed the quick disconnect clamps of the docking & internal transfer mechanism (SSVP) to firm the joint.
The Soyuz spacecraft is intended to remain docked to the space station for the remainder of Expedition 24 to serve as an emergency escape vehicle.
Undocking difficulties 
Landing, originally scheduled for 1:34 UTC 24 September, was postponed due to difficulties in undocking the Soyuz spacecraft from the ISS. The crew entered the Soyuz TMA-18 on 23 September and closed the main hatch at 6:35 pm EDT. Skvortsov, Kornienko and Caldwell Dyson experienced problems getting a tight seal and were forced to open the Soyuz hatch for a quick inspection. The hatch later was sealed, but Expedition 25 flight engineer Yurchikhin working inside the space station had problems confirming a tight fit with the hatch on the ISS side of the interface. After an extended leak check, flight controllers in Moscow decided the docking interface was tight and leak free. As the countdown neared for undocking, commands were sent to open hooks on the MRM2 module side of the interface. But the mechanism did not respond. It was not clear what caused the hooks not to respond, however, Yurchikhin reported finding a small gear floating from the mechanism when he removed a cover.
A second landing window was missed at 4:35 UTC. But Russian engineers were unable to resolve the problem with the docking mechanism and the undocking attempt was called off. The Soyuz TMA-18 crew removed their pressure suits, opened the Soyuz hatch and returned to the space station.
Marking the end of Expedition 24, Skvortsov, Kornienko and Caldwell Dyson successfully undocked their Soyuz TMA-18 at 10:02 pm EDT on 24 September from the Poisk docking port on the Zvezda module. After undocking and a normal descent, the Soyuz-TMA 18 spacecraft landed at 5:23 am GMT near Arkalyk, Kazakhstan. At that time the space station was orbiting 220 miles above over the Pacific Ocean off the coast of Japan.
Russian recovery teams and helicopters were on hand to help the crew exit the spacecraft and adjust to gravity after 176 days in space.
Mission insignia 
The Soyuz TMA-18 mission patch was designed by Nastya Berezutskaya of Kurchatov, Kursk region.
- NASA TV coverage of the launch of Soyuz TMA-18
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