September 07, 2016

Update From Mojave: Preparations for Unity’s Flight Test Program

In the near future, our new spaceship, VSS Unity, will take to the skies for the first time. Having spent years designing, manufacturing, and testing the parts and subsystems that make up SpaceShipTwo, followed by several months of thorough and rigorous Integrated Vehicle Ground Testing, we are excited to take Unity into her natural airborne environment for the start of her flight test program.

Experimental flight test programs are by definition open-ended, and to a great extent each test depends on the data from the test that precedes it. There is no guarantee that everything will work perfectly the first time, and like all programs seeking to take bold steps, we will inevitably have times when things don’t go as planned. Our team’s biggest challenge is to use meticulous planning and preparation to ensure that any such setbacks are dealt with safely, and that every outcome, whether it matches our expectations or not, informs and improves future performance.

We are helped greatly in this respect by the fact that VSS Unity is, of course, the second SpaceShipTwo vehicle to undergo flight testing. Our first SpaceShipTwo, VSS Enterprise, flew 54 times prior to its test flight accident, generating an enormous volume of data and experience. These data points helped us build safety improvements into VSS Unity. The data also allow us to plan out a flight test program that is safer and potentially more efficient: in many cases we will be re-confirming measures of vehicle performance rather than experiencing them for the first time. That advantage generates increased levels of confidence and should benefit our rate of progress.

In any human spaceflight program there is, rightly, a high level of attention paid to crew safety—including not only what happens when everything is happening as planned, but also what happens when something unexpected happens at any stage of flight. At Virgin Galactic, this approach is brought sharply into focus by the fact that all our flight tests are crewed by at least two pilots. This means that even for relatively more simple and brief flights, we need to be prepared to run a full abort scenario to bring our pilots home safely.

As a case in point, the very first flight that VSS Unity makes will be what we call a Captive Carry test – the spaceship will remain “mated” to the WhiteKnightTwo carrier aircraft (VMS Eve) for the duration of the flight, from takeoff all the way through landing. Although it will be great to see our beautiful new spaceship in the air, VSS Unity will be some way from demonstrating her full potential during that first flight. But this flight isn’t just a dress rehearsal; it is an excellent way to generate valuable test data. Throughout the flight, WhiteKnightTwo will serve as a unique “flying wind tunnel,” letting us safely capture high fidelity aerodynamic performance data on the vehicle. Our pilots, mission controllers, and ground operations teams will gain further experience operating a crewed flight. By bringing the vehicle and our crew home safely after the start of the mission but prior to spacecraft release and rocket ignition, they will effectively also be testing out one of our abort modes. Finally, the flight test will confirm extensive simulation and ground testing by showing the real performance of many subsystems and components at cold temperatures, low atmospheric pressures, and high aircraft-like altitudes.

All of those data points will be very useful for us as we move into what comes next: a series of glide flight tests, during which Unity is released to fly home on her own, followed by rocket-powered flight tests of increasingly ambitious scope.

We could not be more excited to move to this next stage of our test program. After years of important in-factory testing, our engineering and operations team are eager to move out from our hangars and to start testing in the open skies. In addition to providing critical data, the coming captive carry flight will be an emotional milestone for our company—the first time ever that a vehicle built by The Spaceship Company and operated by Virgin Galactic has ever taken to the skies. This journey to flight has been arduous but rewarding, and we can now move forward with the confidence that comes from knowing that every vehicle component, sub-system, and procedure has been tested and re-tested prior to these flights.

We look forward to sharing our next steps with the world. Please stay tuned to this site and our social media channels (Twitter, Instagram, Facebook, YouTube, and LinkedIn) for more information as our flight testing program progresses.