NASA announces new window for next Space Shuttle mission
NASA announced 1-19 July 2006 as the new launch planning window for Space Shuttle Discovery's mission (STS-121). The window gives the agency time to do additional engineering work and analysis to ensure a safe flight for Discovery and its crew.
The decision to target July followed a two-day meeting on the external fuel tank's engine cutoff (ECO) sensors. The sensors indicate whether the tank still has fuel during liftoff. During testing, one of the four ECO sensors had a slightly different reading than is expected. Shuttle officials have decided they will remove and replace all four liquid hydrogen sensors.
For more information see NASA's news release