SpaceX is set to test launch its Falcon Heavy rocket, which aims to become the world's most powerful rocket in operation, capable of reaching the Moon or Mars some day.
The rocket will launch at 1:30 pm (1830 GMT) from Cape Canaveral, Florida. It is the most ambitious yet for SpaceX, and industry experts see it as a game-changer as it could potentially propel the company to lead the modern day space race.
"NASA may decide to use it (the Falcon Heavy) as a way of fast-tracking its plans to get to the Moon and Mars," Erik Seedhouse, assistant professor of applied aviation sciences at Embry-Riddle Aeronautical University, told AFP.
According to Jason Davis of the Planetary Society, today's launch is a "huge deal, even for a spaceflight company that routinely accomplishes huge deals."
A mannequin, in a futuristic spacesuit, strapped into CEO Elon Musk's very own cherry red Tesla car is on board.
"Starman in a Red Roadster," Musk posted on Instagram yesterday, showing the rocket's payload on a pedestal, aiming skyward.
Musk has also said David Bowie's hit "Space Oddity" would play in the vehicle during the launch.
Space X released an animated video to preview the launch, which showed all three rocket boosters returning to upright landings on earth, while the car and mannequin sailed into orbit after emerging from the protective nose cone.
"[The roadster will] get about 400 million km away from Earth, and it'll be doing 11km/s," Musk told reporters in a briefing yesterday. "We estimate it will be in that orbit for several hundred million years, maybe in excess of a billion years."
He added that three cameras attached to the car would provide "epic views".
The launch at Florida's Kennedy Space Center is expected to be witnessed by thousands of spectators who are expected to descend on the centre.