So Close, But No Cigar: Demo-2 Scrubs Due to Weather — UPDATED

The countdown got all the way to T-17 minutes, but the weather did not cooperate and the launch of SpaceX’s Demo-2 had to scrub for today.  The next opportunity is Saturday, May 30 at 3:22 pm ET.  Earlier today, the weather forecast showed 60 percent favorable, but that dropped to just 40 percent as the evening progressed.

The launch can only take place when the location of the launch site is correctly phased with the orbit of the International Space Station (ISS), Demo-2’s destination.  It was an instantaneous launch window — it either took place at 4:33:35 pm EDT or not at all.

The weather at Cape Canaveral was pretty bad all day long, even including a tornado warning.  But forecasters were optimistic it would pass just in time to clear three weather violations:  natural lightning, field mill (electricity in the atmosphere), and attached anvil cloud.

As the countdown neared the end, a weather officer was heard saying that if they could wait just 10 more minutes past the launch time the weather system would pass.

Unfortunately, that was not an option.

The Falcon 9 rocket, the Crew Dragon spacecraft, and the crew of Doug Hurley and Bob Behnken all were in perfect shape.

The crew was philosophical, as Hurley conveyed:  “We understand that everybody’s a little bummed out.  It’s just part of the deal. The ship was great.”

NASA TV coverage of Saturday’s launch attempt will begin at 11:00 am ET.  That is also an instantaneous window at 3:22 pm ET.  A second backup opportunity is on Sunday at 3:00 pm ET.

In mid-morning, the Air Force 45th Weather Squadron forecast the chances of favorable weather on Saturday and Sunday as a 40 percent “Probability of Violation” (POV), which meant a 60 percent chance of good weather.

By evening, however, the forecast had reversed, with a 60 percent POV so only a 40 percent chance of “go.”

NASA and SpaceX have an extensive set of weather “launch commit criteria” for Crew Dragon launches.