Shuttle Launch Delayed

fizzix writes "Weather has delayed the launch of Discovery to tomorrow (Sunday the 2nd), but not everyone thinks it is ready to go. CNN reports both the chief engineer and the chief safety officer gave it a 'no go' for launch. Despite their reservations, barring inclement weather the shuttle is planned to liftoff at 3:26 ET." Update: 07/02 05:00 GMT by Z : I said launch not lauch. Fixed headline.

Comments

SpaceFlightNow (as usual) has great coverage

[xmas2003]

STS-121 Mission Status Center - 'nuff said.

Slight confusion over the submital

[beebware]

The details in the Slashdot posting are slightly incorrect. Todays/yesterdays launch (the scheduled on on the 1st of July) was postponed at T-9minutes after a 40 minute scheduled hold (if it's scheduled, why didn't they add it into the count down?) and approximately 3 minutes of 5 into an "extended hold" (after they "polled" all the various sections of the launch team). Then the decision was made the "scrub" (abort) the launch due the weather being too unpredictable and there being storm clouds (anvil clouds) within 20 miles of the emergency landing strip (although they have got backup landing strips in France and Spain). They will retry the launch tomorrow, and can abort for any reason up to 31 seconds before main ignition.

At the moment, they are still "go" for the launch tomorrow.

BTW: You learn a lot from watching the live stream on nasa.gov!

Re:Slight confusion over the submital

[endernet]

The 45 min hold at T-9:00 is standard. It's used for making up time if they take too long on some pre-flight procedures. I think there is a 10min scheduled hold in there at about T-20:00 as well. Why is it not included in the countdown? Because they can chose to use all the 45 min, or only some of it.

Re:Slight confusion over the submital

[Anonymous Coward]

storm clouds (anvil clouds) within 20 miles of the emergency landing strip (although they have got backup landing strips in France and Spain)

Just a small correction there; the strips in France and Spain aren't backup strips, the two locations serve different purposes. If there is a failure early in the launch sequence then they can in theory just ditch the attachments, turn around, and land at the emergency strip near the launch site. ("In theory" because this maneuver is so insanely difficult that it's been said to require about seven different miracles to be successful.) Past a certain point the shuttle can no longer make it back to Florida, so then the abort procedure changes to continue approximately on course and land on the far side of the Atlantic. This part is where the sites in France and Spain come into play. There are few, if any, scenarios where either side could be used, so you end up with a weird situation where bad weather in a place four thousand miles away can scrub the launch because you need to be able to abort there if something goes badly wrong.

Today was the opposite. The transatlantic sites were clear but the strip in Florida itself was too cloudy, so they couldn't go.

This is yet another advantage of simpler capsule systems. The abort modes for those are all extremely simple and reliable compared to the Shuttle's. You fire the escape tower, get away from the rockets, ride down and open the parachutes when you get to the right altitude. As long as the weather isn't so horrible that it sinks the capsule in the ocean, everything should be pretty much fine.

Apollo 12 got hit by lightning during launch and still landed on the Moon, but the Shuttle can't launch if there are storm clouds within 20 miles. The wonders of modern technology.