Space Shuttle Endeavour launches for mission STS-123

March 11, 2008 Space Shuttle Endeavour successfully launched this morning from Launch Complex 39A at the Kennedy Space Center, on mission STS-123 to assemble the International Space Station (ISS). Lift-off occurred at 06:28:14 UTC (02:28 local time). On board was a crew of seven astronauts; Mission Commander Dominic Gorie, Pilot Gregory Johnson, Robert Behnken, Michael Foreman, Richard Linnehan, Takao Doi and Garrett Reisman.

All except Reisman will return to Earth aboard Endeavour in two week's time. Reisman, a member of the ISS Expedition 16 and 17 crews, will remain aboard the Space Station, replacing Léopold Eyharts who launched aboard STS-122 last month.

During the 16-day mission - the longest Shuttle flight in support of the ISS - the crew will install two major ISS components. the Kibō Pressurised Logistics Module and the Canadian Special Purpose Dexterous Manipulator (SPDM). The Kibō Pressurised Logistics Module is the first of three components which will form the Japanese Experiment Module (JEM). It will be temporarily installed on a spare docking port of the Harmony module of the Station, and will later be fitted to the main pressurised experiment module, which is slated for launch aboard STS-124, to be flown by Discovery in late May.

SPDM, also known as Dextre, is a twin robotic arm system, or Remote Manipulator System (RMS), which will be installed on the end of the Space Station's Canadarm2 robotic arm. It will allow complex tasks to be completed without the need for a spacewalk.

Five extra-vehicular activities are planned for the mission. The first three of these will be to assemble, install and test the Dextre SPDM. This will be followed by an EVA to test new tile repair techniques in the event of a Shuttle becoming damaged on a later mission. This test comes ahead of the planned STS-125 mission to service the Hubble Space Telescope in August. The final EVA will be to stow the Orbiter Boom Sensor System (OBSS) on the Space Station.

This usually remains on the Shuttle for launch and landing, however as the next mission, STS-124, is carrying a very large payload - the JEM pressurised experiment module - the OBSS cannot be accommodated in its payload bay for launch. Because it will be needed once the Shuttle reaches orbit, Discovery will collect the OBSS from the ISS, and return it to Earth at the end of its mission. The OBSS is used to conduct photography of the orbiter's heat shield, in order to check for damage, similar to that which caused the Columbia accident.

Two minor problems occurred during the launch. Firstly, the primary Flash Evaporator System failed, resulting in a switch to the backup system, which performed normally. The Flash Evaporator System is used to cool the Shuttle prior to the deployment of its radiators. The radiators were deployed normally following payload bay door opening, once the Shuttle was in orbit. The other issue was that instrumentation failed for a small number of Reaction Control System (RCS) thrusters, which are used to control the Shuttles attitude.

Neither problem is expected to affect the mission. The ascent to orbit has been initially assessed as "clean" in terms of debris impacts, the only concern is a suspected birdstrike ten seconds after launch, however it is believed that Endeavour was not travelling fast enough to sustain damage.

This is the 122nd launch of the Space Shuttle, the 21st of Endeavour, and the 25th Shuttle mission to the ISS. It also marks the ninth, and second manned, orbital launch of 2008. Launch occurred at night, making this the Shuttle's 30th night launch. This flight was originally scheduled to launch on February 14th, but after the previous mission, STS-122, was delayed due to bad sensors inside the external fuel tank, STS-123 was pushed back to no earlier than March 11.