Back in 1994, Peter Diamandis started a nonprofit foundation X-Prize (https://www.xprize.org/) to encourage the development of private space exploration. In 2004 two Irani-Americans Anousheh Ansari, an astronaut herself, and her brother-in-law Amir Ansari, donated $10M to the X-Prize foundation, renamed to Ansari X-Prize, for a contest prize for a non-government private entity who would successfully launch a manned space vehicle twice within two weeks reaching at least 328,000 feet (63 miles or 100km, also called Kármán line which is considered where the edge of space starts).

So, let’s talk about who is this guy and his companions who started this private space flight endeavor. Burt Rutan, who is affectionately called the Magician of Mojave, is a legendary and an accomplished aerospace engineer and a former United States Airforce test pilot who is credited with at least 300 unique aircraft designs, 40 of them still flying today—the most popular ones are VeriEZ and LongEZ, both pusher canards. Burt also designed Voyager which flew non-stop without refueling around the world in 1986 for 9 straight days, setting an endurance record. Voyager is in National Air & Space Museum in Washington DC at the entrance of the museum.

Long before Boeing and other manufacturers started using composite construction in their aircraft (e.g., 777), Burt was already using them in his design successfully—several experts considered him a pioneer in using composites in aircraft designs. This kind of construction is called composite is when the foam is sandwiched between fiberglass or carbon-fiber cloth and glued with specialized epoxy which gets hardened after curing.

Let’s talk about Burt’s spacecraft design—the exciting part for me at least in this story. Burt, given his maverick nature, decided on a two-tier design which was previously done by NASA and US Airforce for X-1 which was dropped-launched from a B-29 bomber and flown by another legendary test pilot Chuck Yeager who broke the sound barrier in October 1947. Burt opted for a similar design where the mothership would take the spacecraft to 50,000 feet and then the spacecraft's own rocket would fire, taking it to reach the desired altitude of 328,000 feet minimum. The mothership was called White Knight One (shown in the picture). The reasoning behind this 2-tier approach was if he designed the spaceship as a single-vehicle like a traditional rocket or Space Shuttle it would have required a large amount of fuel consequently a much larger vehicle just to get to 50,000 feet let alone 328,000 feet. However, if he split it into two vehicles or two phases of the flight, one that would carry the spacecraft to a certain altitude make the engineering problem of designing a lighter spacecraft easier and he opted for the 2-tier design.

White Knight One was powered by two GE turbojet engines and as expected of any Burt’s design is made of light-weight composite material. White Knight One was designed to carry SpaceShipOne, the spacecraft, attached to its underbelly and dropped-launched at 50,000 feet. SpaceShipOne was another unique design not done before (at least to my knowledge). It is inspired by the badminton shuttlecock that no matter how high it goes, it will slowly land on its cork base during the freefall because of the low center of gravity (CG). Burt designed the wings of SpaceShipOne that swing up upward (called feathering) when the vehicle reaches the top and since there is no air resistance at that altitude feathering maneuver does not require much energy. At that point pilot let it float slowly towards earth, just like a shuttlecock, without much intervention. Once it reaches the lower atmosphere, the pilot brings the wings back to the normal configuration and glides the vehicle towards the landing site in Mojave. Why this design was chosen by Burt? Re-entry is the most difficult part of space travel as proven by NASA for decades while the vehicle is at supersonic speeds. This requires vehicle is designed and protected from the heat that is generated from air friction. If the vehicle is never going to be supersonic and does not generate heat it avoids the complexity of adding a heat shield, re-entry angle, etc.