Space is, as Star Trek puts it, the "Final Frontier". Still a tiny market by anyone's standard, but commercial space tourism has arrived for those who can afford it.
Driven to prove their superiority to each other and to the world during the cold war, as well as to gain a strategic advantage, the Americans and Russians began a space race during the 1960s. In an astonishingly short time period, the US Apollo program landed human beings on the moon. Probes by both Superpowers, and later other nations, began to explore the solar system. Space seemed very close; and at one point tickets to the moon and to non-existing space stations were being sold in the United States.
After the Space Race ended, a new sense of reality set in. The initial enthusiasm over space exploration ended as far as the general public was concerned. The wild dreams of the 60s and 70s died, and mankind turned its attention Earthward again. Space travel beyond Earth's orbit became the exclusive domain of mankind's robotic explorers. Still, successful missions manage to gain world-wide attention; the interest in space seems to lie dormant, but not forgotten.
By the end of the 20th Century, travel into outer space was still exclusively the domain of governmental organizations. Private citizens had no access to space. The exception was a female American teacher, who was supposed to reach Earth orbit in 1986 - but perished in the Challenger disaster.
However, necessity changed the situation with the dawn of the 21st century. Desperate for funds, the Russian space agency began to sell seats on Soyuz launches. Businessman Dennis Tito became the first space tourist in April 2001, and as of October 2005, two more have followed in his footsteps.
The only real obstacle to reaching space is the depth of your wallet. In increasing order of both cost and distance from the Earth:
Edge of space
Flights at altitudes of less than 100 km do not qualify as true spaceflight, but it is possible to see the curvature of the Earth from altitudes as (comparatively) low as 25 km.
Sub-orbital flight is defined as flight at altitudes higher than 100 km/h but at speeds insufficient to achieve orbit. While there are currently no operators offering sub-orbital flight, the privately funded and built SpaceShipOne in 2004 demonstrated that this is a possible market and the race is on to commercialize it.
Orbital flight requires achieving escape velocity, in the Earth's case approximately 8 km/s (18,000 mph). Due to atmospheric drag, orbital flight is only practical at altitudes above 350 km, and this itinerary is likely the most expensive in the world.
In 2005, Russian spacecraft manufacturer Energia and the Russian space agency jointly announced that they would be prepared to offer a flight around the Moon for US$100 million.
Although space food has come a long way in terms of taste and variety in recent decades, the quality and taste is still not up to standards of most connoisseurs of fine cuisine. Due to the high delivery costs, food eaten in space is also some of the most expensive in the world.
Safety in space is relative. Today space flight is much safer than it was in the 1950's and 1960's, but it remains a dangerous environment to put yourself in. Cosmic radiation, extreme temperatures, micrometeorites, engineering mistakes, and lack of atmosphere make any unplanned situation potentially life threatening.