While we were doing the ARM-UAV (Atmosheric Radiation Measurement - Unmanned Aerospace Vehicle, Burt Rutan and his crew at Scaled Composites was working on Tier One which included White Knight and Space One. The Discovery Channel came out and made a documentary on that endeavor. Here is the video, minus the advertisements. It is very well done and shows that there is a huge amount of work and effort that went into the program. Enjoy.