Four astronauts are ready to spend five days in orbit on a mission that includes the first attempted spacewalk by private astronauts.

SpaceX is set to launch a mission that will not only see humans travel the farthest away from Earth since Apollo 17 in 1972 but also conduct the first-ever commercial spacewalk. This is in addition to nearly 40 different science experiments and an attempt to transmit data from space through the Starlink network.

Space is an unnatural environment for humans. We can't survive unprotected in a pure vacuum for more than two minutes. Getting to space involves being strapped to a barely contained chemical explosion.

I'm an astronomer who has written extensively about space travel, including a book about our future off-Earth. I think a lot about the risks and rewards of exploring space. As the commercial space industry takes off,