Polaris Dawn: Billionaire takes off for first private spacewalk

There are an awful lot of firsts for the rookie crew to achieve. Isaacman has been in space only once before and the other three have never flown in space.

“There’s a feeling that there are a great many risks here,” according to Dr Adam Baker, a rocket propulsion specialist at Cranfield University.

“They have set themselves a lot of ambitious objectives and they have relatively limited spaceflight experience.”

“But in counter to that, they have spent several thousand hours simulating the mission. So, they are doing their best to mitigate the risks.”

If the mission is a success, some analysts believe that it will be the start of an explosion of ever greater and cheaper private sector missions taking more people further than government space agencies have.

But Dr Baker takes a more cautious approach.

“The record so far has been a huge amount of money spent by the private sector, lots of dribs and drabs of publicity, but much less than 100 additional people on top of the 500 or so government-funded astronauts travelling to space and back, and many of those only for very brief periods.

“Spaceflight is difficult, expensive and dangerous, so expecting to see large numbers of even just well-off members of the population, as opposed to the ultra-rich, flying into space soon, or expecting you might be among them, is unlikely.”