Virgin Galactic's Vehicles.
SpaceShipTwo uses all the same basic technology, carbon composite construction and design as SpaceShipOne. However it is around twice as large as that vehicle and will carry six passengers and two pilots. It is 60ft long with a 90" diameter cabin which is similar in size to a Falcon 900 executive jet albeit with no floor dissecting the cabin allowing maximum room for the astronauts to float in zero gravity. Each passenger gets the same seating position with two large windows: one side window and one overhead, so that, if you don't want to float free in space, and you'd rather just remain in your seat, you still get a great chance to see the view. No more squabbling over who has the best seat!
The spaceship can be thought of as an air launched glider with a rocket motor and a couple of extra systems for spaceflight. Just like any conventional flying machine, it requires aerodynamic forces to provide its stability and control which, clearly, it only has whilst in the atmosphere. In space it follows a purely ballistic trajectory, but here it can use small thrusters known as the reaction control system (RCS) which allow the pilots to maneuver the vehicle in space and provide a changing view for the passenger astronauts.
The spaceship is powered by a hybrid rocket motor. This type of system is not a new idea but offers important safety and environmental advantages over liquid or solid systems that are more commonly used on manned space vehicles. In particular, it means that the pilots will be able to shut down the SpaceShipTwo rocket motor at any time during its operation and glide safely back to the runway.
For more details of the SpaceShipTwo rocket motor please see the section on Safety. Perhaps the most radical feature employed by SpaceshipOne and now SpaceShipTwo is the unique way it returns into the dense atmosphere from the vacuum of space. Burt Rutan designed the unique feathering system which does away with the need for sophisticated computer driven flight control systems or the need to rely on the pilots. Instead it uses aerodynamic design and the laws of physics for a carefree and heat free re-entry followed by a glide runway landing. For more details on SpaceShipTwo's feathered re-entry system see the section on Safety.
Virgin Mothership Eve
The first WhiteKnightTwo, christened VMS Eve after Richard Branson's mother, was revealed to the public for the first time in July 2008 and started its test flight program later that year. At the first roll-out in Mojave it was described as an aviation milestone and for good reason: it is the largest all carbon composite aviation vehicle ever built and the most fuel efficient of its size. It has a unique capability to carry heavy payload (around 35,000lbs) to high altitude (around 50,000ft) and a range of over 2000 nautical miles. Remarkably, for a vehicle of its size, it is also capable of performing high and zero g maneuvers.
When it came to designing WhiteKnightTwo, Burt Rutan, as always, did not feel constrained by convention. SpaceShipOne was mounted under the fuselage of its mothership, WhiteKnightOne. But SpaceShipTwo was going to be much bigger; if it were to be mounted in a similar fashion then the new mothership would require exceptionally high ground clearance and would need excessively long undercarriage. So, a twin fuselage layout was chosen. (see above)
Each of WhiteKnightTwo's fuselages has a dihedral wing and the spaceship will be placed centrally between them, where the wing tips are joined at the highest point of this elongated 'W-shape' wing. With its fuselages some 50ft apart, WhiteKnightTwo's payload area is large and readily accessible from the ground - an open architecture approach which maximizes its future utility. The extraordinary result looks appropriately out of the ordinary, as one might expect from a piece of 21st century space launch hardware.
Whilst its form is remarkable enough, even more so is the innate strength of this large but delicate-looking craft. Despite its 140ft wingspan, it is capable, not only of flying zero-g parabolas, but also of 6g turns. This combined with the fact that each fuselage is in effect a replica of the spaceship fuselage will allow passengers to experience and train in the typical g levels they will encounter during a SpaceShipTwo flight in a cabin that will look and feel like the spaceship cabin. Furthermore, with its powerful spoiler flaps, WhiteKnightTwo can also duplicate the SpaceShip's approach flight path angle, making it a highly useful in-flight simulator for this important part of SpaceShip's mission.
So, in addition to its primary role of carrying and releasing SpaceShipTwo, WhiteKnightTwo also may play secondary roles in passenger and pilot training.