A Closer Look At Virgin Galactic’s Launch Vehicles
Throughout the space industry, we are seeing a large number of different companies and agencies working to reach space. While some attempt to reach orbit and deliver payloads, others travel to the edge of space and provide a once-in-a-lifetime experience for the crew onboard. Virgin Galactic is the latter of the two and does it in a very unique way using two different launch vehicles.
Virgin Galactic uses two separate vehicles to reach the edge of space and safely return back to the surface of Earth. These two vehicles are named WhiteKnightTwo and SpaceShipTwo. Together they propel up to a crew of 6 hundreds of thousands of feet from the surface. Here I will go more in-depth into the design of these vehicles along with the purpose and future of Virgin Galactic.
While this launch vehicle does not reach orbit, it still completes an immensely difficult task in reaching the edge of space. In addition, Virgin Galactic chose to design a rocket that is far from conventional. These reasons among others help make their service stand out from different companies within the industry. It also intrigues people to learn more about how the system actually works.
WhiteKnightTwo
Due to the uniqueness of how Virgin Galactic reaches the edge of space, we first need to look at an additional vehicle that is necessary for the launch process of SpaceShipTwo. Specifically, Virgin Galactic uses two separate vehicles that attach and help each other for each mission. This consists of WhiteKnightTwo and SpaceShipTwo. WhiteKnightTwo is a custom-built, carrier aircraft, specifically built for this operation and mission. This dual fuselage jet aircraft features four engines and is designed to carry SpaceShipTwo up to an altitude of around 50,000 feet. To put it in simpler terms, the spacecraft is attached between the two fuselages of WhiteKnightTwo, and released from the aircraft once at the correct altitude.
While the concept of air-launching space vehicles is not new, it is ideally suited to commercial spaceflight for reasons of safety, passenger experience, and energy efficiency. The first WhiteKnightTwo, VMS Eve, was rolled-out in 2008 and has completed an extensive test flight program. VMS Eve is the largest all composite aviation vehicle in service and has a unique heavy payload, high altitude capability. The catamaran design provides a large and easily accessible payload area and facilitates clean separation when the spaceship is released. The twin cabins come from the same mould as the spaceship. This enables efficient manufacture but also provides a potential training platform for both spaceship pilots and passengers. This aircraft features an impressive wingspan of 41 meters and a length of 24 meters. This wingspan is similar to a Boeing B-29 Superfortress. During a flight, this aircraft will provide a few seconds of weightlessness prior to the suborbital event and separation of the two vehicles. Similar to your standard airplane it takes off and lands on a runway. This helps reduce costs as the primary expense is fuel, and speeds up launches because it only needs a slight refurbishment before the next flight. So far it has performed very well, not only in tests but in actual missions carrying passengers aboard SpaceShipTwo.
SpaceShipTwo
The next key vehicle in Virgin Galactic’s launch process is responsible for reaching the edge of space. SpaceShipTwo is a reusable, winged spacecraft designed to carry eight people or 6 crew and two pilots, into space safely and with high frequency. SpaceShipTwo is powered by a hybrid rocket motor that combines elements of solid rockets and liquid rocket engines. Both types of rocket engines have important advantages; the hybrid aims to combine the simplicity of a solid motor with the controllability of a liquid. SpaceShipTwo’s rocket motor can be shut down quickly and safely at any point during the flight. You will see many different features and components surrounding this launch vehicle that is focused on safety. This is because the primary purpose of SpaceShipTwo is to carry humans to the edge of space for an incredible experience.
SpaceShipTwo’s most innovative feature is its unique capability to change its shape in space to ensure a repeatable safe re-entry. By rotating its wings and tail booms upwards while in space, the vehicle’s stability and rate of deceleration in descent is controlled by aerodynamic forces. This “feathering” design takes the best from both the traditional capsule and winged space vehicle designs, and adds a little magic of its own. The “feathering” concept is often compared to a badminton shuttlecock or birdie, and proves that sometimes the most disruptive designs can emerge from the most humble of origins.
SpaceShipTwo’s cabin has been designed to maximize safety, comfort, and astronaut experience. Exposure to G-forces during SpaceShipTwo’s ascent and descent is safely and comfortably managed thanks to the custom-designed, articulated seats. The cabin is exceptionally spacious, with an interior specifically designed to optimize the out-of-seat zero-gravity experience for the astronauts. In addition, one of the best parts of going to space could easily be the views you get to experience. For this reason, SpaceShipTwo features more windows than any other spacecraft in history. This allows each of the crew members on board to get a spectacular view of Earth and more. With the exception of the rocket motor’s fuel and oxidizer, which must be replenished after each flight, SpaceShipTwo is a fully reusable spacecraft. This is important for not only cutting down on costs but speeding up the downtime between launches.
Technical Design
Now that we know some of the basics behind the design and purpose of SpaceShipTwo, we can take a closer look at the design. Starting at the bottom of the nose of the vehicle, you have a nose skip. This is a simple design for high friction landing gear to ensure a safe and controlled landing. At the front of the vehicle, you also have additional thrusters. These help control the pitch and yaw of the spacecraft while in zero gravity. The lower left side features an entry and exit door. This large cabin door was designed for easy entry and egress of the vehicle. Towards the front and edges of the spacecraft, there is a thermal protection system. This ensures the spacecraft withstands the heat of the partial reentry. At the very rear, you have the hybrid rocket system providing the primary thrust. On either side towards the end there are elevons. These are actuated by the pilot’s center stick for vehicle pitch and roll control. In addition, there are electric servo horizontal stabilizers for trim control on either side. Lastly, you have the main valve bulkhead. This includes a slosh baffle, valve, and injector igniter components.
Conclusion
There are many different destinations and ways to reach space. Even the edge of space presents what seems like an impossible feat. Safely transporting a crew of up to 6 hundreds of thousands of feet from the surface is quite the task. Virgin Galactic is managing to do it in a very unique way with the help of WhiteKnightTwo and SpaceShipTwo. Together they are practically fully reusable vehicles providing people with a once-in-a-lifetime experience. While they are not reaching orbit and delivering payloads, this work still provides good innovation and opportunity within the space industry. As time goes on we can hope for the company’s success and wait to see what they come up with in the future and its impact on the space industry.