Forget the stories of NASA’s famous “Vomit Comet,” the plane that provides training flights for future astronauts. According to Virgin Galactic CEO George Whitesides, the company’s flights to space—a 90-minute experience up and down again—shouldn’t upset passengers’ stomachs.

“I have done several zero g flights,” Whiteside told Fortune in an interview. Maybe not surprising as he is a former NASA chief of staff, which explains why he also says he knows a lot of astronauts. “These days, as long it’s not many repeated [flights], most people aren’t bothered.”

News this week that Virgin Galactic plans to go public through a merger has put more attention on the company’s plans to become the first publicly-traded space tourism company, and gotten many wondering what, exactly, the experience might be like. According to the company, reservations have been closed for about five years, and there’s no word on when they’ll reopen. But, depending on the company meeting its goals, those who previously signed up with a paid deposit could expect to fly within the next four to five years.

Count Whitesides himself among those early adopters. Before he joined Virgin Galactic as CEO, he signed up for two seats for himself and his wife (they booked early at the advance rate that Whitesides said was $250,000 per ticket).

The company says that it now has full or partial payments from more than 600 people from across 60 different countries. “Some are people who always wanted to go to space,” Whitesides said. “Some are people who are yearning for the next big adventure. Some aspire to experience the transformational mindsets that NASA astronauts have described.”

There is also an additional list of 2,500 people, Whitesides told Fortune, who also want to sign up. “We functionally put a pause on selling about five years ago,” he said, noting that the 2,500 did not include the 600 customers with deposits paid.

That is a large amount of disposable cash, though it does include three days of pre-flight training. Given that Virgin Galactic had years to assemble its waiting list, it might be tempting to assume that the market would be maybe 350 people a year. But Whitesides doesn’t see that as a legitimate analysis or limit.

“It’s a new product,” he said. ” You can’t just divide by years and say that’s the market. It’s like saying, ‘What’s the market for cell phones?’ and taking the first three years of sales [as the baseline]. We believe the total number of people who want to experience this is far greater than the capacity to be supplied by us or anyone else.” He believes that will translate into a target of “several hundred” customers flying a year in the near term to, eventually, 1,000 to 2,000. “That would be a tremendous success.”

Still, it is an audience limited by disposable cash. And the $250,000 figure? You might do well to forget it, at least for now. I think the prices will go up a bit,” Whitesides predicts, with prices perhaps dropping over time, but no hint as to how low.

That would also be a lot of flights. According to the company’s website, its SpaceShip Two carries six people, which would mean, at an eventual 2,000 passengers a year, multiple flights a day.

Virgin Galactic estimated in its press release that the merged public company would have an enterprise value of $1.5 billion, which would be equal to 2.5 times its anticipated 2023 revenues of the space tourism business, or approximately $600 million.

Those who do want to go should find the experience not too taxing. “Medically speaking, we think the vast, vast majority of adult humans can do this experience because it’s only 3 or 4 Gs,” Whitesides said, comparable to a moderate (though lengthy) roller coaster ride.

Sounds like quite an adventure.

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