SpaceShipTwo is a spacecraft that is intended to one day take tourists into space. Manufactured by The Spaceship Company, the spacecraft is in the testing stage. Commercial flights are expected to begin around 2015.
The technology for SpaceShipTwo was forged in competition for the Ansari X-Prize, which was created to spur the development of private spaceflight. After predecessor SpaceShipOne won the prize in 2004, two companies, Scaled Composites and Virgin Galactic, formed The Spaceship Company to work together to commercialize the technology.
Developing SpaceShipTwo has come with its share of setbacks, both privately and publicly. Scaled Composites experienced a fatal explosion in 2007 that delayed development of the rocket engine. The date for the first spaceflight has continually pushed back.
But Virgin Galactic has done several drop tests of SpaceShipTwo as of late 2012, with a rocket-powered flight expected as the next step.
SpaceShipTwo's ancestor, SpaceShipOne, had a single purpose: to make it into space twice, and return. SpaceShipOne represented Scaled Composites' entry into the X-Prize, where $10 million was up for grabs to the first non-governmental entity to achieve the objectives. SpaceShipOne was manufactured by Mojave Aerospace Ventures, a joint venture of Scaled Composites and Microsoft co-founder Paul Allen.
Scaled Composites founder Burt Rutan had a different vision of spaceflight than usual. Most of the cargo that leaves Earth does so upon a rocket that goes straight from the ground into space. SpaceShipOne launched instead from underneath a carrier aircraft, called WhiteKnightOne, then separated and rocketed to more than 60 miles (100 kilometers) in altitude.
Just before the spacecraft won the X-Prize in 2004, Virgin Galactic's Richard Branson announced that he would work with Scaled Composites to manufacture a commercial version that would bring space tourists into suborbit. Development then began on SpaceShipTwo.
"We hope to create thousands of astronauts over the next few years and bring alive their dream of seeing the majestic beauty of our planet from above, the stars in all their glory and the amazing sensation of weightlessness," Branson said in September 2004.
Since then, more than 530 people have signed up to take a quick joyride into space. The reported price: $200,000 apiece.
As development proceeded, the company focused on putting together a launch area. The state of New Mexico offered Virgin Galactic a taxpayer-funded $225 million facility in December 2005, called SpacePort America. There, Virgin Galactic would establish its global headquarters as well as see spaceflights.
The company rolled out several construction milestones in the next year, but the momentum halted in 2007. A fatal fire during a ground test sent shockwaves through Scaled Composites and the greater "new space" community. Three Scaled Composites employees died, and others were injured, during a routine ground test. Work was briefly suspended as an investigation into the cause was launched.
Things began to turn around in July 2008, when Virgin Galactic held a major launch event to showcase WhiteKnightTwo, who would carry SpaceShipTwo partway to orbit. The first carrier aircraft would be called "Eve." Before 2008 finished, Eve had its first successful test flight.
The first SpaceShipTwo was unveiled in December 2009. It's named VSS Enterprise, after the famous "Star Trek" craft. (Enterprise was also the name of the first shuttle, but it was used for glide tests only and never made it into space.)
Crewed test flights in Enterprise began in July 2010. The next major milestone will be rocket-powered test flights, which will likely happen in 2013.
The company completed a major glide test in late 2012 that had the spacecraft in its "powered flight configuration", meaning that the hybrid rocket motor and all other components were built in. Virgin Galactic will do at least two more glide tests before turning on the power.
Virgin also bought out Scaled Composites in 2012 to obtain full ownership of The Spaceship Company.
"The completion of the acquisition comes as Virgin Galactic and Scaled begin to plan the handover of the [SpaceShipTwo] development program to Virgin Galactic," Virgin stated.
"Scaled [is] fully committed to the final portion of the [WhiteKnightTwo] and [SpaceShipTwo] test flight programs prior to Virgin Galactic commencing commercial operations."
A typical flight profile
When it begins flights, Enterprise will carry six passengers. The spaceship will fly to 50,000 feet in altitude underneath the carrier aircraft WhiteKnightTwo, then separate for the trip into space. SpaceShipTwo will fire its engines for about 70 seconds, then shut off for the final coast to 60 miles (110 kilometers.)
The passengers will feel weightless for about five minutes, Virgin says, with room "to allow for an out-of-seat zero gravity experience as well as plenty of large windows for the amazing views back to Earth."
Next, Enterprise will turn back to Earth. It will "feather" its rudders, which means the rudders will turn up to 90 degrees to increase the drag and control the yaw of the spacecraft. This will allow better control as it goes through the atmosphere.
"The feather configuration is also highly stable, effectively giving the pilot a hands-free re-entry capability, something that has not been possible on spacecraft before, without resorting to computer controlled fly-by-wire systems," Virgin stated.
At 70,000 feet, Enterprise will have enough air around it to move the rudders back to a configuration that allows for gliding. It will then land back on Earth on a normal runway.
Virgin hopes to commence flights in earnest around 2015. Aboard the first flight will be Branson and some members of his family. Branson, an amateur adventurer who is famous for his publicity stunts, has been interested in space since at least the Apollo era.
The lengthy delay in the first Virgin flights caused some ticketholders to ask for refunds, but the vast majority stuck around eager for the experience to begin. Industry watchers have applauded Virgin's patient approach.
"They're taking the time necessary to make sure the vehicles are as safe as they possibly can be before they take paying customers up," said John Gedmark, executive director of the Commercial Spaceflight Federation, in a 2011 SPACE.com interview.
"There's never going to be such a thing as perfectly safe spaceflight, but they're going to get as safe as they possibly can."
— Elizabeth Howell, SPACE.com Contributor