Two NASA astronauts were being strapped in for a historic SpaceX rocket launch Wednesday afternoon — but the weather could still derail their trip.

Doug Hurley and Bob Behnken rolled up inside Teslas around 1:30 p.m. to launch pad 39A in Cape Canaveral, Fla., for a mission to the International Space Station with Elon Musk’s space venture that would mark the first time a private company has sent humans into orbit.

With less than three hours until the planned liftoff, the doors of their gull-winged Tesla Model X SUVs — built by another Musk business — opened outward and upward to let the space veterans onto the launch pad at NASA’s Kennedy Space Center.

Both men were already suited up, and took their seats inside the brand-new Dragon capsule, where crew members began strapping them in.

But the weather could potentially complicate the plans for the liftoff, which will be attended by President Trump and Vice President Mike Pence.

Blastoff is scheduled for 4:33 p.m., but launch controllers around midday put the chances of acceptable weather for liftoff at around 50-50 due to rain, clouds and thunderstorms.

If it goes ahead as planned, the mission will be the first time in nearly a decade that the country has launched astronauts into orbit from US soil.

With Post wires