Artwork: The BFR would assume the roles performed by current SpaceX vehicles People will soon be able to fly from city to city within minutes, rocket and car entrepreneur Elon Musk says. Mr Musk made the promise at the International Astronautical Congress (IAC) in Adelaide, Australia. A promotional video says the London-New York journey would take 29 minutes. Mr Musk told the audience he aimed to start sending people to Mars in 2024. His SpaceX company would begin building the necessary ships to support the mission next year. He says he is refocusing SpaceX to work on just one type of vehicle - known as the BFR - which could do all of the firm's current work and interplanetary travel. IAC Artwork: Musk envisages colonies on Mars As well as being the CEO and chief designer at SpaceX, Mr Musk also founded the Tesla electric car company and is chairman of SolarCity which specialises in renewables technologies, such as high-storage batteries. He has attracted a rock-star following from fans who love his visionary thinking. And although his promises have often taken much longer to deliver, he has achieved a number of notable firsts. These include 16-in-a-row successful landings of orbital-class rockets back on Earth after they have completed their missions. Two of these rockets have even flown a second time. Elon Musk's 'underground road plan' Key to his thinking is the concept of reusability. Space activity is currently expensive only because it is disposable, he says. There is no reason, he claims, why rocket systems cannot be made to operate like airliners where the most significant ongoing cost is the fuel in the tanks. His Falcon 9 rocket is partially reusable; the BFR would be totally reusable. The same vehicle would fly time and time again. Mr Musk recognises that his ambitious timelines sometimes slip. When he put up a slide in Adelaide stating that the first cargo (no humans aboard) versions of BFR would go to Mars in 2022, he said: "That's not a typo, although it is aspirational."