The Scaled Composites Model 339 SpaceShipTwo (SS2) is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic.
SpaceShipTwo is carried to its launch altitude by a Scaled Composites White Knight Two, before being released to fly on into the upper atmosphere powered by its rocket engine. It then glides back to Earth and performs a conventional runway landing. The spaceship was officially unveiled to the public on 7 December 2009 at the Mojave Air and Space Port in California. On 29 April 2013, after nearly three years of unpowered testing, the first one constructed successfully performed its first powered test flight. Virgin Galactic plans to operate a fleet of five SpaceShipTwo spaceplanes in a private passenger-carrying service and has been taking bookings for some time, with a suborbital flight carrying an updated ticket price of US$250,000. The spaceplane could also be used to carry scientific payloads for NASA and other organizations. On 31 October 2014 during a test flight, VSS Enterprise, the first SpaceShipTwo craft, broke up in flight and crashed in the Mojave desert. A preliminary investigation suggested the feathering system, the craft’s descent device, deployed too early. One pilot was killed; the other was treated for a serious shoulder injury after parachuting from the stricken spacecraft. The second SpaceShipTwo spacecraft, VSS Unity, was unveiled on 19 February 2016. The vehicle is undergoing flight testing.
The SpaceShipTwo project is based in part on technology developed for the first-generation SpaceShipOne, which was part of the Scaled Composites Tier One program, funded by Paul Allen. The Spaceship Company licenses this technology from Mojave Aerospace Ventures, a joint venture of Paul Allen and Burt Rutan, the designer of the predecessor technology.
SpaceShipTwo is a low-aspect-ratio passenger spaceplane. Its capacity will be eight people — six passengers and two pilots. The apogee of the new craft will be approximately 110 km (68 mi) in the lower thermosphere, 10 km (6.2 mi) higher than the Kármán line which was SpaceShipOne’s target, although the last flight of SpaceShipOne reached a one-time altitude of 112 km (70 mi). SpaceShipTwo will reach 4,200 km/h (2,600 mph), using a single hybrid rocket engine — the RocketMotorTwo. It launches from its mother ship, White Knight Two, at an altitude of 15,000 metres (50,000 ft), and reaches supersonic speed within 8 seconds. After 70 seconds, the rocket engine cuts out and the spacecraft will coast to its peak altitude. SpaceShipTwo’s crew cabin is 3.7 m (12 ft) long and 2.3 m (7.5 ft) in diameter. The wing span is 8.2 m (27 ft), the length is 18 m (60 ft) and the tail height is 4.6 m (15 ft). SpaceShipTwo uses a feathered reentry system, feasible due to the low speed of reentry. In contrast, orbital spacecraft re-enter at orbital speeds, closer to 25,000 km/h (16,000 mph), using heat shields. SpaceShipTwo is furthermore designed to re-enter the atmosphere at any angle. It will decelerate through the atmosphere, switching to a gliding position at an altitude of 24 km (15 mi), and will take 25 minutes to glide back to the spaceport. SpaceShipTwo and White Knight Two are, respectively, roughly twice the size of the first-generation SpaceShipOne and mother ship White Knight, which won the Ansari X Prize in 2004. SpaceShipTwo has 43 and 33 cm (17 and 13 in) -diameter windows for the passengers’ viewing pleasure, and all seats will recline back during landing to decrease the discomfort of G-forces. Reportedly, the craft can land safely even if a catastrophic failure occurs during flight. In 2008, Burt Rutan remarked on the safety of the vehicle:
This vehicle is designed to go into the atmosphere in the worst case straight in or upside down and it’ll correct. This is designed to be at least as safe as the early airliners in the 1920s … Don’t believe anyone that tells you that the safety will be the same as a modern airliner, which has been around for 70 years. In September 2011, the safety of SpaceShipTwo’s feathered reentry system was tested when the crew briefly lost control of the craft during a gliding test flight. Control was reestablished after the spaceplane entered its feathered configuration, and it landed safely after a 7-minute flight. *Wiki and Scaled Composites