If all goes as planned, within a couple of years, tourists will be rocketing into space aboard a Virgin Galactic space plane  paying $200,000 for about four minutes of weightlessness  before coming back down for a landing on a New Mexico runway.

Sitting in the next seat could be a scientist working on a research experiment.

Science, perhaps even more than tourism, could turn out to be big business for Virgin and other companies that are aiming to provide short rides above the 62-mile altitude that marks the official entry into outer space, eventually on a daily basis.

A $200,000 ticket is prohibitively expensive except for a small slice of the wealthy, but compared with the millions of dollars that government agencies like NASA typically spend to get experiments into space, “it’s revolutionary,” said S. Alan Stern, an associate vice president of the Southwest Research Institute’s space sciences and engineering division in Boulder, Colo.

He is a spirited evangelist for the science possibilities of what is known in aerospace circles as suborbital travel. Just as important as the lower cost, scientists will be able to get their experiments to space more quickly and more often, Dr. Stern said.