Musk sets goal for two flights in 24 hours with same Falcon 9 rocket

May 10 (UPI) -- Block 5 will be the last version of the Falcon 9 rocket, according to SpaceX CEO and founder Elon Musk.

But before it's retired, Musk hopes Block 5 will significantly alter the economics of rocketry.

In a phone conference with reporters ahead of Thursday's Block 5 launch, Musk said Block 5 will undergo "minor adjustments" here and there, but that the newest version marks the last major overhaul of the Falcon 9.

Even the overhaul wasn't really an overhaul, according to Musk, but rather is the culmination of hundreds of changes that came together to yield a new version -- a new version Musk and SpaceX have high expectations for.

"We expect it to be a mainstay of SpaceX's business," Musk said, "and to complete something of the order of 300 flights before retirement."

Those hundreds of little changes, including upgrades of materials, adding more resilient heat shields, reinforcing various components and boosting engine thrust.

All of the upgrades were made to enhance reusability, Musk said.

"No scheduled maintenance for 10 flights," Musk said. "The only thing that needs to be changed is the propellants being reloaded."

Of course, safety checks will still need to happen, to make sure everything is in working order. And the new payload will have to be loaded onto the rocket. But Musk and SpaceX liken the newest -- and last -- version of the Falcon 9 to an airplane, capable of landing, refueling and flying again on quick turnaround.

"We plan to complete two flights with the same rocket in 24 hours by the end of the year," Musk said. "That would really be amazing."

If each airplane could only fly once, Musk pointed out, air travel would be prohibitively expensive. That's the reality for rockets. SpaceX wants to make space travel more like air travel, with each craft capable of taking several flights. The company expects reusability to slowly bring down the costs of space flight.

After the first ten flights, Block 5 rockets will be refurbished. With refurbishment after every tenth flight, Musk believes a Block 5 rocket will be capable of conducting upwards of 100 flights.

But while only small adjustments are planned for Block 5, the rocket has yet to prove itself. It will have to meet thousands of technical and safety requirements before NASA deems it worthy of carrying manned spacecraft.

The new version gets its first chance to show off on Thursday. After that, Musk and his engineers will take apart the rocket to confirm the rocket is truly capable of rapid reuse.

"It will be a few months before it's ready to fly again," Musk said.