TOKYO - A JAPANESE firm on Tuesday began accepting reservations for couples who really want to make the big leap - by blasting into space to exchange their wedding vows.

Each happy couple will spend 240 million yen (S$3.1 million) for the ceremony in a small space vessel, which will shoot up 100 kilometres into the sky.

During the hour-long flight, the couple will spend several minutes in zero gravity during which they will exchange their vows with up to three guests present, said Mr Taro Katsura, a spokesman for Japanese firm First Advantage.

The couple would perform most of the ceremony before takeoff 'so that they can say their vows and look out the window,' Mr Katsura said.

The firm is offering the space marriages in a tie-up with US-based Rocket Plane, which will conduct the flights from a private airport in Oklahoma.

From the spaceship, the couple would probably be able to see the outline of the Earth although they will not be far enough into space to allow complete floating, Mr Katsura said.

Despite launching the offer in Japan, the company said it expected most of its customers to be from China or Arab Gulf nations. There are currently no plans to start the space weddings in the United States, Mr Katsura said.

Space tourism has been seeing a boom of sorts since 2001, when American millionaire businessman Mr Dennis Tito paid US$20 million (S$27 million) to Russia's space agency to become the first person to pay his own ticket into space.