Have you ever wanted to go to space?

It’s an adventure many dream of, but which so far has been closed to almost all but a few highly-trained professionals. But with the recent rise in space tourism companies, like Elon Musk’s SpaceX or the Jeff Bezos-founded Blue Origin, an extra-terrestrial holiday might be within reach for everyday sightseers within the next decade.

Unfortunately, the reality might not be so fun, according to former NASA astronaut Anna Fisher.

“The one thing I am concerned about with tourists in space is people thinking you can just get on a rocket and just go into space,” she said in an interview with The Telegraph. “It’s not like riding a commercial aircraft, not at all, and I can see all these problems with people up there and throwing up and messing up somebody’s flight that they paid $250,000 for.”

Yes, it turns out there’s a reason astronauts go through years of training before they leave the planet. Space adaptation syndrome, or “space sickness” is a real thing, and it affects about two-thirds of astronauts – even after they spend so long preparing for it.

“Your first moments in space are not always your best. I remember when we were in the shuttle and you are at 3Gs for the last two minutes or so, and it’s a little hard to breathe and then the engine shuts off, and boom, you’re weightless, it’s that fast”, described Fisher. “I was extremely grateful that I had eaten absolutely nothing for breakfast.”

Space sickness is thought to be caused by problems adapting to the zero-gravity environment. Not only does weightlessness upset your inner ear’s ability to find your balance, but you’re also having to deal with fluids shifting around in your body, headaches, and a puffy face. One of the best safeguards against it is a cramped, constrained environment – not exactly what you think of when you hear “luxury holiday” – and although some medications can help, they carry their own risks of blurred vision or sleepiness – which is not ideal if you’ve spent your life savings on the experience.

To train astronauts for the bizarre environment of outer space, NASA simulates weightlessness by flying aircraft in extreme, rollercoaster-like patterns – a program affectionately known as the “Vomit Comet”. The experience is open to members of the public: in 2007 Stephen Hawking, who planned to travel to space with Virgin Galactic before his death earlier this year, described a flight on the Vomit Comet as “amazing”.

So would a trip to space really be worth it? Despite the excitement surrounding space tourism, the reality is that you may well end up spending hundreds of thousands of dollars just to spend the whole time puking. And, as Fisher warns us: “I was lucky I never threw up, because if you think throwing up is bad here on the ground it’s really bad in space.”