Discovery Launch No Earlier than Sunday

The Sun sets tonight as Discovery awaits a Sunday launch.

NASA Space Shuttle Mission Manager's have elected to purge the external tank and trouble shoot the hydrogen fuel line valve beginning Thursday afternoon. NASA says a launch by Discovery would not occur until at least Sunday, and before March 17th.

"Clearly an external leak on the ground side..." states shuttle management. Prior to the scrub, launch control saw the leak and tried cycling the valve several times to hopefully dislodge any debris or ice. This leak is like nothing they had seen before.

Several dynamics are in play right now with a lot of unknowns. First, an external tank purge takes twenty hours, and thus an inspection of the leaking hydrogen valve can not be investigated until early afternoon tomorrow.

Next, the valve change out and what technicians need to perform would occur on Friday. "We have really good access to this area... we have to disconnect" several items to get to the valve, stated the Team stated this evening. Following successful valve cycle checks, Mission Managers will meet on Saturday to elect to fly on Sunday.

A Sunday evening launch time would see the solid rocket boosters ignite at 7:43:38 pm EDT.

Sunday is one of the last days to fly a nearly full duration mission, however Shuttle program managers state that Discovery can launch up until this Tuesday, March 17th. Whether Discovery flies on Sunday, Monday or Tuesday of next week, the mission of STS-119 will be a shorter than planned flight - with two instead of four spacewalks.

One last dynamic is the fact that an Atlas V has the eastern range for both this Sunday & Monday. Will they give up their days on the range and allow NASA to fly before they do?

Weather wise, Sunday and Monday looks all right, with Sunday currently being 80% favorable and 70% favorable on Monday, stated Kathy Winters of the Air Force Meteorology group at Kennedy Space Center this evening.