This message from Gina Sunseri, our Houston-based producer:
Two good sources are telling me NASA will be forced to admit today the May launch window for the next Shuttle mission is impossible.
They will have to swap out the ECO sensors (fuel cutoff switches) on the external tank they just shipped to the Kennedy Space Center last month.
Engineers and managers are having an all-hands-on-deck meeting now in Houston.
This swap will take 22 days, which kills any chance of making a May launch.
There are four ECO (short for Engine Cut-Off) sensors inside the Shuttle’s orange external tank, near its base. They signal that the tank is running dry, preventing the Shuttle’s engines from continuing to fire when there is no fuel to power them.
To get to them, engineers have to cut through the foam insulation on the base of the tank, then open an access hatch. It’s not a job to be done when the tank is standing upright on its launch platform. If you remember, ECO sensors did them in twice before they launched Discovery last year. The first time, they were less than 2-1/2 hours to launch, with the astronauts settling into their seats in the crew compartment, when one of the sensors sent a faulty signal–and the launch was put off for two weeks.
The next window is July 1st-20th.
UPDATE, 4:30PM Gina’s sources were good. NASA held a 4pm (EST) news conference and has just put out the following statement:
NASA ANNOUNCES NEW WINDOW FOR NEXT SPACE SHUTTLE MISSION
NASA announced today July 1 to 19, 2006, is 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.
Space Shuttle Program Manager Wayne Hale made the announcement during a news conference from NASA’s Johnson Space Center in Houston. 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.
"We’ve been saying for months that our engineering work would determine when we fly our next mission. Targeting July is the right choice in order to make smart decisions," said Bill Gerstenmaier, NASA associate administrator for Space Operations.
Gina adds that NASA believes it can still launch three shuttles in 2006…partly because it has to. The plan is to be finished with them in 2010, and time’s a’ wastin’.
Of course, an irony in all this is that to build the Shuttles’ replacement, NASA is cannibalizing all the science programs that led to the findings we’ve been talking about since last week. The mission to Jupiter’s moon Europa, believed, like Saturn’s moon Enceladus, to be a home to liquid water, is canceled, at least for now. Anyone want to send a new probe to Saturn? It won’t happen any time soon.