I’ve never seen a night launch of the Shuttle (or any large launch vehicle–the biggest I’ve ever seen was a Delta II out of Vandenberg, from a motel in Lompoc). But there’s only a forty percent chance of flying tonight, due to concerns about low-level clouds with a front moving in. I have to decide by six or so if it’s worth the drive up to the Cape, or risk having to watch from a hundred fifty miles away on the beach down here. If it doesn’t go tonight, the next most likely success would be on Sunday night, due to forecast of high winds on Friday and Saturday. Of course, if it slips long enough (well into next week) the window will have slid backward enough that it’s no longer a night launch.

[Update at 2:30 PM EST]

Weather’s getting worse:

Kennedy Space Center already is overcast and getting worse by the hour. The satellite imagery indicates that the cloud cover that was feared as a potential launch show-stopper is going to intensify.

All three of the Transoceanic Abort Landing sites in Spain and France are experiencing unacceptable weather conditions in case an unprecedented emergency landing were attempted because of some problem during the early stages of flight.

There are low clouds and showers within 20 miles of the landing sites in Zaragosa and Moron in Spain. At the French emergency site in Istris, winds are forecast to be too strong to land.

No probability of launch update, though. I have to think it’s dropping below forty percent. This is the MMT’s bane–having to make a decision to send the crew out to lie on their backs for a couple hours, and hoping for the best against long odds. It’s looking less and less likely that we’ll make the drive up.

[3:15 PM Update]

They’re still saying a sixty percent chance of clouds preventing launch. But what’s the joint probability of having good weather at the Cape, and at all the abort landing sites? I have to think it’s a lot less than forty percent at this point. It’s going to be really hard to motivate myself to make the drive.