Although SpaceX has chosen not to set a definite launch date, the Falcon Heavy was due to perform a series of static-fire tests this week.
Crews at the Kennedy Space Center in Florida were spotted on Monday loading the vertical Falcon Heavy spacecraft with fuel at Launch Pad 39-A.
Unfortunately, the tests were twice postponed due to “logistical and safety concerns”.
It is thought that SpaceX has now been made to step aside to allow the launch of the United Launch Alliance’s (ULA) Atlas V rocket later today (January 19).
Read more: ATLAS V ROCKET LAUNCH LIVE STREAM
Falcon Heavy, which has been described as “the most powerful operational rocket in the world by a factor of two”, is a new and extremely ambitious spacecraft so delays were always likely.
But if it can successfully fire all 27 of its powerful engines, the colossal rocket should be given the green light for lift-off later in January or early February.
Kennedy Space Center said: “Currently this launch is targeted for no earlier than January 2018, with a date and time to be determined.”
The Falcon Heavy will be the single most powerful rocket to blast off from the space centre since the Apollo mission’s Saturn V in 1973.
Standing 70m tall and 12.2m wide, the Falcon Heavy boasts an impressive ability to carry over 60 tonnes worth of payload into Low Earth Orbit and nearly 17 tonnes as far as Mars.
On it maiden voyage, Falcon Heavy is due to carry a cherry-red Tesla Roadster car playing David Bowie’s Space Oddity on a loop.
Elon Musk, who owns both SpaceX and Tesla, said: “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.”
The billionaire added that a car makes for less “boring” cargo.
Posting on Instagram, he said: “Test flights of new rockets usually contain mass simulators in the form of concrete or steel blocks. That seemed extremely boring.
“Of course, anything boring is terrible, especially companies, so we decided to send something unusual, something that made us feel.
“The payload will be an original Tesla Roadster, playing Space Oddity, on a billion year elliptic Mars orbit.”
The main goal of the launch is to test the space faring capabilities and ability to send cargo into orbit around Mars.