SpaceX is poised for the first test launch Tuesday of its Falcon Heavy, which aims to become the world's most powerful rocket in operation, capable of ferrying people to the Moon or Mars some day.
The launch is the most ambitious yet for SpaceX, and has been hailed by industry experts as a game-changer because of its potential to propel the California-based company to the front of 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.
Tuesday's launch is a "huge deal, even for a spaceflight company that routinely accomplishes huge deals," said Jason Davis of the Planetary Society, describing the Falcon Heavy as "mythical."
No people are on board, just a mannequin wearing a futuristic spacesuit, strapped into CEO Elon Musk's very own cherry red Tesla car.
"Starman in a Red Roadster," Musk posted on Instagram Monday, 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.
"I love the thought of a car drifting apparently endlessly through space and perhaps being discovered by an alien race millions of years in the future," Musk tweeted last year.
An animated video released by SpaceX to preview the launch showed all three rocket boosters returning to upright landings on Earth, while the car and mannequin emerged from the protective nose cone and sailed into orbit.
The blast-off is scheduled for 1:30 pm (1830 GMT) from Cape Canaveral, Florida.
The destination is deep space, into an orbit about the same distance from the Sun as Mars -- but not all that close to the Red Planet itself.
Musk has cautioned that the maiden launch of the Falcon Heavy -- a project he first unveiled in 2011 -- may indeed fail.
"Will be in deep space for a billion years or so if it doesn't blow up on ascent," Musk said on Twitter in December.
Even if there is a disaster on the launchpad Tuesday, Seedhouse said it is unlikely to harm the reputation of SpaceX -- already a top cargo supplier to the International Space Station under a $1.6 billion contract with NASA and busy with a steady stream of satellite clients and government payloads.
"Last year they had more launches than any other country in the world -- never mind any other company," Seedhouse said.
"Every failure they have had they have bounced straight back," he said.
Most powerful in operation
The Falcon Heavy is essentially three Falcon 9 rockets in one, with a total of 27 Merlin engines.
These engines "together generate more than five million pounds of thrust at liftoff, equal to approximately eighteen 747 aircraft," said SpaceX.
The rocket is designed to carry nearly 141,000 pounds (64 metric tons) into orbit, more than the mass of a fully loaded 737 jetliner.
"Falcon Heavy was designed from the outset to carry humans into space and restores the possibility of flying missions with crew to the Moon or Mars," SpaceX said in a statement.
"When Falcon Heavy lifts off, it will be the most powerful operational rocket in the world by a factor of two," it added.
The Falcon Heavy is designed to lift more than twice the payload of the next closest operational vehicle, the Delta IV Heavy, at a far lower cost.
The Delta IV Heavy costs about $350 million per launch, according to United Launch Alliance.
SpaceX's Falcon Heavy starts at around $90 million.
"That is way, way, way below anything else in the government launch industry," Seedhouse said.
Previous rockets that are no longer in commission have been more powerful than the Falcon Heavy -- including the Saturn V moon rocket, last flown in 1973, which delivered more payload to orbit.
The Soviet era Energia, which flew twice in 1987 and 1988, was also more powerful than the Falcon Heavy.
The United States has been unable to send its own astronauts to space since 2011, when the 30-year shuttle program ended, leaving the world's astronauts to rely on Russian Soyuz rockets for transport to the International Space Station.
NASA is building its own massive rocket, called the Space Launch System, but costs are high and the project is years away from completion..