Written by Derek Kessler on
Sunday, 16 December 2007
Shuttle program managers are planning for a January 10, 2008, launch for the space shuttle Atlantis. The launch was delayed earlier this month after fuel sensors failed prior to two attempts. The delay will allow for engineers to dig into the problems that have plagued the fuel sensors and to have some time off during the holiday season.
The STS-122 mission to carry the ESA's Columbus Laboratory into orbit to the International Space Station first attempted to launch on December 6th, but two of the four fuel sensors - called engine-cut off sensors - failed to register appropriate readings during fueling. The ECO sensors monitor the level of liquid hydrogen fuel inside the shuttle's massive 500,000 gallon external fuel tank and are designed to shut off the three main engines in the rear of the shuttle in the event of a sudden unexpected loss of fuel. NASA flight rules require that three of the four sensors be operating properly. If the engines were to fire without fuel they could suffer catastrophic damage that would likely destroy the shuttle during launch.
The December 6 launch was cancelled and engineers fixed the problem. Shuttle managers decided to revise the launch rules so that all four ECO sensors and a back-up monitoring system be working. They fueled the shuttle early on the 9th for a launch later that day and one of the sensors again failed, forcing NASA to again scrub the launch. This was the first time this year that NASA has delayed a shuttle launch; three other shuttles launched this year without incident.
With the Atlantis mission pushed back to 2008, NASA currently has six shuttle launches slated for the year, the most since 2001. The shuttle fleet was grounded after the 2003 loss of Columbia. NASA has been extremely cautious with regards to launch safety ever since, resulting in a two-year break in shuttle flights and a presidential directive to retire the fleet by 2010.
The construction of the International Space Station is dependent upon the cargo-hauling capabilities of the three remaining space shuttles. The next shuttle mission after STS-122 will be the Endeavour, which is slated for a Valentine's Day (February 14th) launch to carry the first of three segments of the Japanese Kibo science module to the ISS.
Shuttle program managers are planning for a January 10, 2008, launch for the space shuttle Atlantis. The launch was delayed earlier this month after fuel sensors failed prior to two attempts. The delay will allow for engineers to dig into the problems that have plagued the fuel sensors and to have some time off during the holiday season.
