Demo-2 forecast: 50-50 chance of good weather for Saturday's historic SpaceX launch

If SpaceX and NASA are going to make history with a launch from Kennedy Space Center on Saturday, they’re going to have to beat the odds. Meteorologists still say there is only a 50-percent chance of acceptable weather for the second Demo-2 launch attempt.

Two NASA astronauts are ready to make history with the first crewed launch from American soil since 2011. The space agency has been buying seats aboard Russian rockets until private companies were ready to take over the job of ferrying crews to the space station.

RELATED: Cleared for historic launch, SpaceX likely to win out-of-this-world ‘capture the flag’ race

The crew-carrying version of SpaceX’s Dragon capsule made a successful automated flight last year; now the company is planning to send Doug Hurley and Bob Behnken on a test flight to the space station.

But they’ll need Mother Nature to cooperate. Wednesday afternoon’s launch attempt was scrubbed late in the countdown because of the potential for lightning from a nearby storm – a common occurrence during Florida’s tropical summers.

Storms roll through Cape Canveral during Wednesday's countdown. FOX 13 photo 

Forecasters with the Space Force’s 45th Weather Group say there is an even chance that thunderstorms will again prevent a safe launch for Saturday’s 3:22 p.m. launch attempt. Their Friday morning forecast predicted a 50-percent likelihood of good weather, slightly more optimistic than the 40-percent chance they were offering yesterday.

As the day heats up Saturday, any storms that bubble up will drift towards the east coast – and Cape Canaveral – thanks to the lack of a strong sea breeze to sweep them inland.

There is no room in the countdown for a delay because the launch window is instantaneous. The timing – mid-afternoon in this case – is dictated by the space station’s position in orbit as well as the short amount of time that the Falcon 9’s super-cold fuel can stay ready for flight in the rocket’s tanks. The crew's sleep cycle is also taken into account.

If Saturday’s attempt is delayed for any reason, there is another opportunity on Sunday afternoon. The weather forecast is similar, though.

"Although it seems a welcome drying trend over Florida will soon be upon us, it’s not clear if the timing will be soon enough for Sunday’s attempt," the official forecast noted.