Fifty years after Russian cosmonaut Yuri Gagarin became the first human to experience the wonders of spaceflight, commercial companies appear to be on the cusp of a breakthrough industry -- space tourism.

In a bid to open up the final frontier to an expanding group of people, private firms are racing to provide paying customers with unique orbital and suborbital experiences.

Suborbital spaceships would take passengers up to space at an altitude of about 62 miles (100 kilometers) -- commonly known as the edge of space -- before returning to Earth. These passengers would get a glimpse of the edge of our planet and the blackness of space while experiencing several minutes of weightlessness.

Virgin Galactic's private SpaceShipTwo spacecraft and its mothership WhiteKnightTwo flies over the Golden Gate Bridge with the Virgin America plane "My Other Ride is a Spaceship" on April 6, 2011 en route to open Terminal 2 at San Francisco International Airport. CREDIT: Mark Greenberg/Virgin America View full size image

Fifty years after Russian cosmonaut Yuri Gagarin became the first human to experience the wonders of spaceflight, commercial companies appear to be on the cusp of a breakthrough industry -- space tourism.

In a bid to open up the final frontier to an expanding group of people, private firms are racing to provide paying customers with unique orbital and suborbital experiences.

Suborbital spaceships would take passengers up to space at an altitude of about 62 miles (100 kilometers) -- commonly known as the edge of space -- before returning to Earth. These passengers would get a glimpse of the edge of our planet and the blackness of space while experiencing several minutes of weightlessness.

On orbital flights, only those who can afford the multimillion dollar ride will have the chance to rocket into low-Earth orbit and visit the International Space Station. But, as the space tourism industry expands and more vehicles are able to take customers into space, these trips could go down in price. [Vote Now! The Best Spaceships of All Time]

In the meantime, space tourism seems poised to launch, and there are a wide range of options available for those who want to experience the thrill of spaceflight. This list is not exhaustive, but provides an outline of various space tourism options available today, as well as some to look forward to in the near future:

Suborbital

Zero G Corporation

Vehicle: G-Force One, a modified Boeing 727-200 aircraft

Price: $4,950 per passenger

This Vienna, Va.-based company, owned by the space tourism company Space Adventures, offers passengers the chance to experience various states of microgravity aboard a modified Boeing aircraft. The G-Force One plane flies a series of 12 to 15 parabolic arcs at various altitudes and angles that mimic different states of microgravity. Each parabolic maneuver allows passengers to experience about 35 seconds of the gravitational state on Mars or the moon. [Vacations in Zero Gravity Come of Age]

The Stern family of Colorado float in weightlessness during a Fourth of July holiday flight aboard a Zero Gravity Corporation aircraft on July 4, 2010.
CREDIT: Steve Boxall/Zero-G

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Since the company's first flight in 2004, Zero G Corp. has flown over 6,000 people, including former Apollo astronaut Buzz Aldrin, and celebrities such as Martha Stewart, rocker Ozzy Osbourne and famed astrophysicist Stephen Hawking.

Still in the works

Virgin Galactic

Vehicle: SpaceShipTwo

Price: $200,000 per passenger

Founded by British billionaire Sir Richard Branson, Virgin Galactic has been making waves in the suborbital spaceflight industry. Virgin Galactic's SpaceShipTwo space plane is designed to be carried into midair by the company's massive WhiteKnightTwo mothership. At an altitude of about 50,000 feet (15,200 meters), the carrier plane releases SpaceShipTwo, which fires its rocket engine and climbs toward the edge of the atmosphere. Passengers will experience roughly five minutes of weightlessness before gliding back for landing.

Virgin Galactic's first SpaceShipTwo passenger spacecraft leaves contrails in its wake during a Jan. 13, 2011, glide test, the fourth in a series of demonstration flights.
CREDIT: Michael Fuchs

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Flights, which will carry six passengers and two pilots, are scheduled to depart from New Mexico's Spaceport America. Virgin Galactic recently completed its longest test flight of the SpaceShipTwo vehicle, and company officials have said that regular space tourist flights should begin in 2012. Despite the hefty ticket price, nearly 400 people have already put down deposits for future flights. [Infographic: Spaceships of the World]

Others in the wings

Other companies looking to break into the suborbital spaceflight market include XCOR Aerospace, Blue Origin and Armadillo Aerospace. The highly secretive Blue Origin, which is founded by Amazon.com CEO Jeff Bezos, is developing a fully reusable suborbital vehicle called New Shepard, which is capable of flying three or more passengers on suborbital flights.

Armadillo Aerospace, a Texas-based company founded by computer game entrepreneur John Carmack, is working on a vertically launched rocket ship to carry passengers to the edge of space. Armadillo Aerospace's deal with Space Adventures will offer these suborbital flights for $102,000 per passenger -- almost half the going rate for a seat on one of Virgin Galactic's joyrides.