The rocket plane, a type called SpaceShipTwo, is about the size of an executive jet. In addition to the two pilots, there can be up to four people in the cabin. The particular SpaceShipTwo that flew on Sunday is named V.S.S. Unity.
To get off the ground, Unity was carried by a larger plane to an altitude of about 50,000 feet. There, Unity was released, and the rocket plane’s motor ignited. The acceleration made people on board feel a force up to 3.5 times their normal weight on the way to an altitude of more than 50 miles.
At the top of the arc, those on board were able to see the blackness of space as well as the curve of Earth from the plane’s windows. They also got out of their seats and experienced about four minutes of apparent weightlessness. Fifty miles up, Earth’s downward gravitational pull is essentially just as strong as it is on the ground; rather, the passengers were falling at the same pace as the plane around them.
The two tail booms at the back of the space plane then rotated up to a “feathered” configuration that created more drag and stability, allowing the plane to re-enter Earth’s atmosphere more gently. This configuration SpaceShipTwo like a badminton shuttlecock, which always falls with the pointy side oriented down, than a plane.
Still, the forces felt by the passengers on the way down were greater than on the way up, reaching six times the force of gravity.
Once the plane was back in the atmosphere, the tail booms rotated back down, and the plane glided to a landing.