Because Bigelow is purchasing whole trips aboard the SpaceX capsule, its schedule would be independent of NASA’s, and the stays could be longer, perhaps 30 or 60 days, said Robert Bigelow, the chief executive of Bigelow Space Operations and Bigelow Aerospace, a sister company that has an experimental inflatable module currently docked at the station.

The company has yet to start looking for passengers. “We have to get to first base, which is getting to the point where we can even have something to talk about,” he said.

Mr. Bigelow also said no fares have been set. “What we realize is there are many different ways to price these seats depending on who you are and what you’re doing,” he said.

Axiom Space of Houston, run by Michael Suffredini, a former NASA space station manager, is also arranging flights and hopes to fly tourists next year.

Both Bigelow and Axiom aim to use the International Space Station as the starting point for setting up their own space stations in orbit. Mr. Bigelow said flying tourists to the International Space Station would give his company experience at handling the complex logistics of arranging spaceflights.

In the 2000s, seven private citizens did visit the outpost, but those trips were arranged through the Russians, which operate half of the base. At the time, NASA said it was not interested in such ventures.

Since then, a variety of options for private spaceflight have started to emerge. Virgin Galactic, founded by the entrepreneur Richard Branson, and Blue Origin, from Jeffrey P. Bezos of Amazon, both plan to carry passengers on short suborbital flights. SpaceX also announced that Yusaku Maezawa, a Japanese clothing company founder, would pay for a trip around the moon on a spacecraft it is building.