In March, 2001, Dennis Tito became the first space tourist, paying $20 million dollars to the Russians for a one-week visit to the International Space Station (ISS). He left Earth on March 30, after spending one month in training with the Russian Cosmonauts. The rest of the countries helping to build the ISS were not pleased with Russia's decision to allow space tourists on the ISS because they were afraid there would be problems. About his trip in space, Tito said that he hopes to open the way for more space tourists. Space tourism could become very popular and common in the twentyfirst century.