Virgin Galactic made history on Monday when it became the first and only commercial space tourism company to trade on the New York Stock Exchange. Shares of the company under the ticker (SPCE) went as high as $12.91, according Yahoo Finance data.

The listing was made possible through the finalized merger between Sir Richard Branson’s Virgin Galactic, and Social Capital Hedosophia Holdings. The latter was a special purchase acquisition company founded by venture capitalist Chamath Palihapitiya. Shares of Social Capital Hedosophia had previously been listed under the symbol (IPOA) and closed at $11.79 last Friday.

“This is an exciting opportunity,” former NASA astronaut Leroy Chiao told Yahoo Finance.

“I think the jury is out as to whether or not space tourism is a sustainable market, but it will be exciting to follow,” the ex-space traveler said.

Virgin Galactic says it already has customer reservations from more than 600 people in 60 countries. In early October, the company also announced an investment of $20 million from aircraft giant Boeing (BA) and, along with Under Armour (UAA), unveiled sleek space suits passengers will wear on flights.

Scott Parazynski, also a former NASA astronaut and author of The Sky Below, sees long term potential for the industry.

“I see ourselves in the barnstorming era of commercial human space travel, and I hold out hope that what's happening in suborbital and low earth orbit space will eventually lead to point-to-point global travel and even touristic space station and lunar outpost flights in the future,” he told Yahoo Finance.

Competition is heating up between other companies, like Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin, that’s making some call it a billionaire space race.

For that reason, some are skeptical about whether space travel will be attainable for everyday citizens — and a flight on Virgin Galactic certainly won’t be cheap. A 90 minute journey will cost a whopping $250,000.

“I'm bullish on commercial human spaceflight as a whole, and it's incredibly exciting that several contenders are about to start launching their first paying customers,” Parazynski said. “What's yet to be seen is if there's a sustainable market at a price point where sufficient customers will pay.”

Indeed, a trip with NASA to the International Space Station as a “private astronaut” carries a staggering $52 million per person price tag that makes Virgin Galactic flights cheap by comparison. For that reason, leaving the earth for tourist purposes may be the first small step in a journey space enthusiasts can only dream of for now.

“I fear that [Virgin’s] addressable market is rather small, and the ability to drop that price point significantly is going to be extremely challenging,” Parazynski added. “That said, there are a number of companies trying to out-innovate one another, and that competition should lead to sustainable solutions in the future.”

According to Chiao, part of the attraction for would-be commercial travelers “is to say that you have been there. Will that luster wear off after the first 700-1000? We will see.”

Clarification: Virgin Galactic will begin trading on the New York Stock Exchange as a direct listing.