Elon Musk will 'eat his hat' if a competitor's rocket flies before 2023

Musk argues that the Falcon Heavy cost substantially less than the competition and is a long way ahead

Elon Musk has said he will "eat his hat" if a competitor's rocket flies before 2023.

The comment was made during a Twitter conversation between the Tesla Motors CEO and Tory Bruno, the chief executive of Space X competitor United Launch Alliance, about its plan to replace its Delta and Atlas rockets with a new, powerful booster called the Vulcan rocket.

It all started when Doug Ellison, a Jet Propulsion Laboratory visualisation producer, shared some calculations that demonstrated in some cases that the Delta IV Heavy rocket could match the performance of Space X's Falcon Heavy.

Musk claimed that Ellison's numbers were based on flawed underlying data and that even if they weren't, the Falcon Heavy cost substantially less than the competition.

"The performance numbers in this database are not accurate. In process of being fixed," Musk said. "Even if they were, a fully expendable Falcon Heavy, which far exceeds the performance of a Delta IV Heavy, is $150M, compared to over $400M for Delta IV Heavy.

Bruno corrected Musk, stating that the Delta IV Heavy goes for about $350M. "That's current and future, after the retirement of both Delta IV Medium and Delta II," he said.

Originally planned for a launch in 2019, the Vulcan rocket's maiden launch now will probably slip into mid-2020 at least. But Musk clearly believes the test flight and Air Force certification process will delay that quite a bit longer, and he's willing to put his millinery where his mouth is.

"Maybe that plan works out, but I will seriously eat my hat with a side of mustard if that rocket flies a national security spacecraft before 2023," he said.

Musk successfully launched the SpaceX Falcon Heavy rocket last week. Billed as a 'risky test-flight', the launch went entirely to plan, and crucially, the return to Earth, which will bring the total cost of sending payloads up in the first place down by huge factors, was at least partially successful.

Two of the rocket boosters made a perfect, synchronised landing in Florida. The central booster, however, didn't have enough propellant for its landing on a sea-drone, and instead crashed into the ocean at around 500kph.

Perfecting this technology will allow space flights to become significantly more affordable, with the Big Heavy billed as being twice as powerful as the next most powerful rocket, but a third of the price tag.