SpaceX chief executive Elon Musk speaking in 2015 in Hawthorne, Calif.  (Ringo H.W. Chiu/AP)

The latest version of the Falcon 9 rocket that SpaceX was to launch from Florida’s Kennedy Space Center Thursday afternoon is designed to be reused so quickly that it would eventually mimic a commercial airliner, according to SpaceX’s founder Elon Musk.

In a call with reporters before the launch, which was postponed until Friday after a last-minute abort, Elon Musk, SpaceX’s founder, said that if all goes well with the upgraded version of the rocket, the company intends to attempt to fly it twice within 24 hours as soon as next year, a monumental achievement that Musk said “would be a very exciting outcome.”

The latest version, known as “Block 5,” would be able to fly at least 10 times with no scheduled maintenance in between flights, Musk said, allowing the company to fly more efficiently and at a lower cost.

“It’s designed like a commercial airliner, and getting all those details right was immensely difficult,” he said. Typically, companies go weeks or even months in between launches. But flying the same rocket to orbit twice in a single day would be unprecedented and, as Musk said, “a ridiculously hard thing.”

“It has taken us, man, since 2002 — 16 years of extreme effort and many, many iterations and thousands of small but important design changes to get to where we think this is even possible,” he said. “Crazy hard. And, of course, we still need to demonstrate it. It’s not like we’ve done it. But it can be done.”

For decades, the first stages of rockets were launched and then ditched into the ocean, never to be used again. But since 2015, SpaceX has been flying its boosters back to land so that they could be reused.

Going into Thursday’s launch of a communications satellite for Bangladesh, which was aborted a minute before launch, SpaceX has recovered a total of 24 boosters, Musk said.  It did not immediately say what caused the company to delay the launch.

Block 5 is the version of the rocket, and the one that SpaceX plans to use to fly NASA’s astronauts to the International Space Station, with test flight beginning as soon as this year. For all its triumphs, SpaceX has never even attempted to fly human beings before. But it and Boeing are under contract with NASA to fly crews to the station.

The latest version of the Falcon 9 is a more robust version of its predecessors, Musk said, that meets all of NASA’s human-rating requirements, which he said “are quite extensive.” He said that the intent was to fly NASA crews on “the most reliable rocket ever built. I hope fate does not punish me for those words, but that is unequivocally the intent.”

As SpaceX prepares to fly NASA’s astronauts for the first time, some of NASA’s safety advisers and members of Congress have raised concerns about its fueling procedures. Because it keeps its propellant at unusually cold temperatures, it would fuel its Falcon 9 rocket shortly before takeoff — and while the astronauts are already on board.

NASA’s standard practice had been to fuel the rocket before the crew boarded, and some accused SpaceX of taking an unnecessary risk.

But in the call Musk dismissed those concerns, while saying it could adjust, if necessary.

“I really do not think this presents a safety issue for astronauts,” Musk said. “But we can adjust our operational procedures to load propellant before the astronauts board. But I really think this is an overblown issue.”

He said that his team and SpaceX feels "really confident. And our most conservative customers and partners, the Air Force and NASA, also feel good about the design intent of this rocket."

But leading up to the first launch of the new version, he didn't want to jinx himself.

"I really don’t want to tempt fate," he said. "There are a lot of new things that could potentially go wrong. There could be a thousand things that could go right with this rocket and one that goes wrong. The reason it is so hard to make an orbital rocket work is that your passing grade is 100 percent."

He paused and said: "Anyway I’m stressed. Any good wishes would be appreciated."