SpaceShipTwo - Design Overview

Design Overview

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 miles) in the lower thermosphere, 10 km (6 miles) higher than Kármán line which had been the SpaceShipOne target (though the last flight of SpaceShipOne also penetrated the 'official' beginning of outer space and reached a one-time altitude of 112 km). SpaceShipTwo will reach 4,200 km/h (2,600 mph), using a single hybrid rocket motor – the RocketMotorTwo. It launches from its mothership, White Knight Two, at an altitude of 15,200 m (50,000 ft), and goes supersonic within 8 seconds. After 70 seconds, the rocket motor cuts out and the spacecraft will coast to its peak altitude. SpaceShipTwo's crew cabin is 3.66 m (12 ft) long and 2.28 m (7.5 ft) in diameter. The wing span is 8.23 m (27 ft), the length is 18.29 m (60 ft) and the tail height is 4.57 m (15 ft).

SpaceShipTwo uses a feathered reentry system, feasible due to the low speed of reentry – by contrast, the Space Shuttle and other 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 kilometres (15 mi), and will take 25 minutes to glide back to the spaceport. Once the passengers return, their passports will receive a spaceflight stamp and they will be awarded their astronaut wings at an awards ceremony. They will also be able to relive their flight from footage filmed during the spaceflight.

SpaceShipTwo and White Knight Two are, respectively, roughly twice the size of the first-generation SpaceShipOne and mothership White Knight, which won the Ansari X Prize in 2004. SpaceShipTwo has 43 cm 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.