The race to launch the world’s first commercial spacecraft intensified on Tuesday with a deal that could let tourists pay $98,000 for a flight to the edge of space.

US company Space Adventures has signed an agreement to sell seats aboard a sub-orbital spacecraft designed by the US aerospace company XCOR. XCOR’s proposed space vehicle, called Xerus, could begin flights within three years, the company says. But completion of the spacecraft will depend on getting financial backing.

XCOR is just one of a number of companies trying to develop a commercial space vehicle. In March 2002, Space Adventures signed deal with two Russian companies that hope to build another sub-orbital spacecraft, called Cosmopolis 21. But while the C-21 was little more than a mock-up, the XCOR’s vehicle design has impressed space experts.