The flight got down to T-18 minutes when they called the abort for weather reasons. Being an instantaneous launch window they could not wait for the weather to clear.
The SpaceX Demo-2 launch was scheduled to liftoff at 6:33 am AEST from the Kennedy Space Centre in Florida. The spacecraft, propelled by a Falcon 9 rocket, was to carry NASA astronauts Robert Behnken and Douglas Hurley to the International Space Station.The Crew Dragon had much higher weather standards than normal rocket flight.
The weather had to be monitored not just around the Kennedy Space Centre, but along a corridor stretching thousands of kilometres across the Atlantic Ocean in case the crew capsule had to escape from its Falcon 9 rocket during the climb into orbit.
Light but persistent rain fell around the space centre throughout the day. Later in the afternoon, the rain stopped and skies began to clear.
About 17 minutes before the scheduled liftoff time, a weather officer informed the SpaceX launch director that the weather conditions would not clear up in time. If the Falcon 9 were to launch just 10 minutes later they were told the mission might have been able to proceed.
But the liftoff time could not be moved. For the spacecraft to be able to meet up with the International Space Station passing overhead, liftoff must occur at a precise moment.
The parameters to screen for acceptable weather downrange were added on top of the standard launch weather rules that track cloud, lightning and wind conditions at Cape Canaveral.
Bit of trivia – the astronauts had steak and eggs for breakfast! Now they are back to quarantine for a few days – see you all on Saturday 19:22 UT or 5:22am Sunday AEST!
Weather forecast on Saturday in Florida and down range is still not ideal so we will watch and see. After that next window is Sunday 1900 UT or 3am Monday AEST.