To Boldly Go To Market: Dave Unwin Reports from the World’s First Purpose-built Commercial Spaceport
Mankind has always wanted to go further, faster and higher. Although surprisingly few commentators picked up on it at the time, the retirement of Concorde was actually a pivotal moment in the history of humanity. It was the first time ever that a transport system had been retired without being replaced by something faster. In the chilly light of a desert dawn, I was out at Mojave Spaceport, California – waiting for a glimpse of the future. High above the desert a single white dot separates into two, as the carrier vehicle VMS Eve drops the VSS Enterprise. The Enterprise glides down to a perfect landing on Runway 30, and barely four hours later I was standing in a hangar between these two unique machines.
So, how do they work? A great deal of the material is classified, but essentially the spaceship is carried aloft by the VMS Eve. This is powered by four turbofans, is the largest all-composite aircraft ever made and has a wingspan greater than a Boeing 757. The dual fuselages are very similar to the spaceship’s – in fact one of them is configured to be identical to the interior of the Enterprise. With a service ceiling of roughly 60,000ft and the ability to provide the occupants with several seconds of weightlessness by flying parabolic trajectories, it is the ideal machine for training flights before an actual space mission. The other fuselage is configured to carry passengers into the stratosphere, and has slightly higher density seating.
At around 50,000ft and 125 knots indicated air speed, the spaceship is dropped. It is powered by a hybrid rocket motor, so-called because they use two very different propellants, which are actually in different states of matter (the fuel is a solid, the oxidiser is a gas).
As soon as the rocket is fired, the nose is pitched up and the machine accelerates to an IAS of approximately 250kts, which equates to a true air speed of 550kts and Mach 3.5. Once the rocket is shut off the vehicle coasts out of the atmosphere, reaching a peak altitude of 350,000ft and affording its occupants some incredible views and also the amazing sensation of weightlessness.
The biggest challenge that space flight pioneer Burt Rutan and his team faced was the massive thermal loads generated as the vehicle enters the atmosphere. The solution, like most brilliant ideas, is brilliantly simple. At its apogee, the pilots reconfigure the entire airframe. A pneumatic ram pivots the wings and tail booms up through 90º, placing the spaceship into the ‘feather’ configuration. The spacecraft is now essentially the same as a giant shuttlecock, and as it falls back into the atmosphere it automatically aligns itself into the optimum attitude for re-entry. Furthermore, it is now in such an incredibly high drag configuration that it never accelerates to the point at which the thermal loads can threaten the structural integrity of the vehicle.
At around 70,000ft, the tail booms and wings pivot back down, reconfiguring the spaceship as a glider. It then glides back to the Spaceport for a normal landing.
Although all the flight testing has taken place at Scaled’s base at Mojave Air and Spaceport, when Virgin Galactic starts commercial flights, operations will shift to Spaceport America in New Mexico. This is the world’s first purpose-built commercial spaceport. The runway is already finished, and the terminal and hangar facility (THF) is expected to be completed this year. As I drove away through the Mojave Desert I felt very privileged. I had just witnessed the world’s first privately built commercial spaceship.