SpaceX, Elon Musk's scrappy interstellar startup, is on the verge of making history as it prepares to send a pair of NASA astronauts blasting off to the International Space Station.

The launch, set for Wednesday at the Kennedy Space Center in Florida, will mark the first time astronauts have been sent into orbit atop a rocket and in a capsule both developed and owned by a private company.

It will also mark the first time in nearly a decade that American astronauts have been launched into space from the U.S.

The two NASA astronauts, Doug Hurley and Bob Behnken, will hurtle into space in a Crew Dragon capsule atop a Falcon 9 rocket, both developed by Musk's SpaceX.

The launch, scheduled for 4:30 p.m. EDT, weather permitting, will mark SpaceX's final test before it can win NASA certification, paving the way for regular ferry service to the ISS starting later this year.

President Donald Trump will travel to Florida tomorrow to watch the flight in person, highlighting the groundbreaking nature of the event.

The flight marks the potential beginning of a new era of private-sector space flight and exploration.

The two astronauts will spend anywhere from a month to nearly four months at the station, before splashing down in the Atlantic in their Crew Dragon capsule, a reentry trip that typically takes about two hours.

SpaceX's big launch on Wednesday also marks a major victory for upstart SpaceX over Boeing  (BA) - Get Report, which had been initially favored to win the NASA contract to develop the spacecraft and rocket for the ISS mission.