US First Human Launch Delayed

SpaceX and NASA will need to wait for their historic launch to the International Space Station after inclement weather postponed the first crewed flight of the Dragon Wednesday. Astronauts Bob Behnken and Doug Hurley were supposed to launch from Florida aboard a Falcon 9 rocket at 4:33 p.m. ET on Wednesday. Hans Koenigsmann, a vice president at SpaceX, said earlier in the week that preparations were complete, but to get off the ground, the team would need "the weather gods ... working with us." The weather gods, it seemed, had other plans. Demo-2 was down to about 17 minutes before launch when SpaceX and NASA officially called it off.

Falcon 9 and Dragon had an instantaneous launch window, so SpaceX weren't able to hold the count and wait until the weather passed. The fuel used to propel the rocket cannot sit in the booster on the pad, where it warms up and can affect performance, and the ISS orbits the Earth -- so any hold would affect the ability to essentially aim Crew Dragon at the space station. There are two backup launch times available over the weekend. SpaceX has said the next window opens at 12:22 p.m. PT (3:22 p.m. ET) on Saturday, May 30, and a subsequent window will open at 12 p.m. PT (3 p.m. ET) on Sunday, May 31. The weather could again be a factor, with recent reports from the 45th Weather Squadron showing only a 40% chance of favorable weather for both backup launch times.



Credits:
https://www.cnet.com/news/spacex-nasa-scrub-historic-demo-2-launch-due-to-weather/