The world’s first crew of “amateur astronauts” is preparing to blast off on a mission that will carry them into orbit before bringing them back down to Earth at the weekend. The four civilians, who have spent the past few months on an astronaut training course, are due to launch on SpaceX’s Falcon 9 rocket from the Kennedy Space Center in Florida at 8.02pm local time on Wednesday (1.02am UK time on Thursday). Barring any glitches, the two men and two women on the Inspiration4 mission are expected to orbit the planet for three or four days, performing experiments and admiring the view through a glass dome fitted to their Dragon capsule, before splashing down in the Atlantic Ocean. Touted as “the world’s first all-civilian mission to orbit”, the launch is the latest to promote the virtues of space tourism and follows suborbital flights in July by Sir Richard Branson on Virgin Galactic’s SpaceShipTwo - which has since been grounded for going off course – and Jeff Bezos on Blue Origin’s New Shepard rocket. While the Inspiration4 crew has had flying lessons, centrifuge sessions to experience the G-forces of launch, and hours of training in SpaceX’s capsule simulator, the mission will be almost entirely automated. The capsule is due to orbit Earth at an altitude of 360 miles (575km), about 93 miles higher than the International Space Station. Elon Musk’s SpaceX announced in February that the billionaire businessman Jared Isaacman, who has clocked up thousands of hours in various aircraft, had chartered the Falcon 9 rocket for himself and three members of the public. He donated two seats to St Jude children’s research hospital in Memphis, Tennessee, and selected Hayley Arceneaux, a former cancer patient at the hospital, and now an employee there, to join him. At 29 years old, Arceneaux is set to become the youngest American in orbit. Also on the mission are Dr Sian Proctor, a geologist and science communicator who made it to the final round of Nasa’s 2009 astronaut selection process, and Chris Sembroski, a US air force veteran and aerospace engineer with Lockheed Martin, who was offered the seat by a friend who won it in a St Jude’s charity raffle. While the Inspiration4 mission is yet another paid for by a billionaire, it marks a milestone in space tourism: never before has an all-amateur crew been blasted into orbit. “It’ll be the first time that a global superpower hasn’t sent people up into orbital space,” Isaacman has said. “When this mission is complete, people are going to look at it and say, ‘It was the first time everyday people could go to space.’” Louis Brennan, professor in business studies at Trinity Business School in Dublin, said SpaceX was “leading the pack” of private sector companies interested in space. He likened space tourism today to the time before low cost airlines created a mass market for air travel. “In the same way, space tourism is likely to remain the preserve of the wealthier classes in the short to medium term, as the cost is prohibitive for people of average means,” he said. “In the longer term, as the costs involve reduce, it is likely to become a mass market activity. However for now and into the short and medium term it will be a niche market.” As the industry moves beyond national space agency contracts to tourism, it will be more crucial than ever to avoid mishaps and disasters. “Safety in space tourism is paramount since any accident involving death or injury runs the real risk of fatally undermining confidence on the part of prospective space tourism customers,” Brennan said.