Gregory Olsen will fulfil his dream to be the next space tourist under a deal signed this week in Moscow.
Dr Olsen could go as early as October
The 60-year-old US businessman and scientist will visit the International Space Station, probably in October.
He will make the trip on a Russian Soyuz vehicle, spending just over a week on the orbiting outpost.
Dr Olsen will become the third space tourist after flights by US citizen Dennis Tito in 2001 and South African Mark Shuttleworth in 2002.
The contract between the Russian space agency and the Space Adventures company arranging Olsen's tour was signed in the last few days, agency spokesman Vyacheslav Davidenko said.
The "ticket of a lifetime" will cost Dr Olsen $20m (£11m). He has already begun his cosmonaut training at Russia's Star City space centre near Moscow.
He will do his own experiments on the ISS
Dr Olsen has long experience working in the scientific sphere and heads the Princeton-based research firm Sensors Unlimited.
The company develops and produces highly sensitive film and photo cameras and works with the US space agency (Nasa).
Apart from testing new Sensors Unlimited equipment in orbit, Dr Olsen plans to take with him a number of self-designed experiments.
These will involve growing crystals on board the ISS and may have applications in his imaging business.