How riding rockets going 4,000 mph into suborbital space could slash international flight times from 22 hours to 2

• Rockets could fly commercial travelers from London to Sydney in just two hours.
• This idea of point-to-point rocket travel, however, could be uncomfortable and inconvenient.

Last month, Australian-based airline Qantas announced the longest nonstop flights ever planned: 20-hour journeys from Sydney to New York or London, slated to launch in 2025.

Just weeks later, a scientific journal claimed that before long those routes might be completed in just two hours — a tenth of the time as Qantas.

The key to this shockingly fast travel? Rockets.

Passengers would travel through space at super-high speeds

In this approach, known as point-to-point rocket travel, "rockets would be used to launch a spacecraft into suborbital flight, which would then travel at speeds of up to 4,000 miles per hour," said David Doughty, CEO of Admiral Jet, a private jet and helicopter charter company.

Large commercial jets currently fly at about 550-600 mph once they reach cruising speed. So, the rockets' speed would make a massive difference in arrival times.

Doughty said the possibility is thrilling.

"It could change the way we think about travel and open up new opportunities for exploration and discovery," he said.

Space companies that are exploring the technology

While no one is going from Down Under to Big Ben in less than 24 hours these days, some space companies are already testing the technology needed for point-to-point rocket travel.

Billionaires including Richard Branson, Elon Musk, and Jeff Bezos are in this new space race with the companies Virgin Galactic, SpaceX, and BlueOrigin.

At the end of May, Virgin Galactic announced its fifth successful space flight and claimed that commercial flights to space — not different destinations on Earth — could start as early as this month.

The military is also working with SpaceX, BlueOrigin, and a third company, Rocket Lab, to explore using point-to-point rocket travel for cargo transports, said Joe Cassady, an aeronautics and astronautics engineer who has worked with the US Air Force and NASA.

Roadblocks to point-to-point rocket travel

Space companies have made significant strides in developing reusable rockets, but there's still a long way to go before they're ready for commercial flights.

"Building the necessary launch facilities, establishing flight corridors, and coordinating with air traffic control systems would require significant investments and collaboration between space agencies and governments," Thompson said.

Then, there are safety considerations.

"Rockets use highly volatile and explosive fuel in large quantities," Cassady said. Because of that, it's likely launch points wouldn't be convenient to major cities, but in remote locations like SpaceX's test site in Boca Chica, Texas, near the border with Mexico.

Finally, the industry will have to consider the environmental impact, both on Earth and in space, Doughty said.

Rocket travel could be pretty uncomfortable and expensive

During launch and landing, passengers would experience significant g-force, Cassady said. Astronauts currently feel about 3 Gs of force, which makes their body weight feel about triple what it does on the ground.

"Because of this, seats would be contoured couches to absorb some of the load," he said.

It's also likely that passengers would need to wear a pressurized space suit and helmet during takeoff — which would last about ten minutes — and landing, which would take about 40 minutes. But, for the 30-60 minutes when you were orbiting, you might get to try a pretty unique experience: weightlessness.

"It is possible that you could remove your pressure suit or helmet and float freely," Cassady said.

No company has announced projected ticket prices for point-to-point rocket trips, but if other space travel is any indication they'll likely be super expensive. Currently, you can book a two-hour space flight with Virgin Galactic for $450,000.

Travelers will likely need to stick to long-haul flights, at least for now

When and if ultra-high-speed rocket travel becomes available, Cassady questions how many people will clamor for seats.

"Will there really be enough people who see the cost, risk, and potential inconvenience of having to depart and land far from their destination as worth the decrease in travel time?" he said.

Cassady is a self-proclaimed "certified space geek" and said he would consider buying a ticket into space. But he's not planning any future point-to-point rocket flights because it's not worth the hassle. However, he is looking forward to another technology that could reduce travel times.

"The chances are much better that quiet supersonic jet transports will be developed in the next five to 10 years and those will cut the longest flight times down enough to be reasonable," he said.

Those flights can use existing airport infrastructure and would look more like the plane rides we're familiar with. Although, there won't be any free-floating.