Ax-1 training
The four members of the Ax-1 crew (right) undergo training at NASA's Johnson Space Center for their commercial mission to the International Space Station.

With uncertain demand for private researchers or astronauts from other national space agencies, companies will need to be open to every market, including tourists, to close their business cases.

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Jeff Foust has more than a decade of experience writing about space policy, entrepreneurial ventures and regulatory affairs. In 2001, he established spacetoday.net to aggregate and summarize the day's space-related news stories. In 2003, he started The...