Unlike rocket-propelled spaceplanes, VSS Unity (SpaceShipTwo) will be released from the VMS Eve (WhiteKnightTwo) mother ship at an altitude of about 50000 ft (~15240 m) and then release the VSS. Unity out. VSS Unity will continue its rocket-powered journey towards low Earth orbit at supersonic speeds.
VSS Unity is a suborbital spaceship, which means it won’t accelerate to escape Earth’s gravity like a space shuttle. Instead, its rocket propulsion allows the train to reach three times the speed of sound, about 3700 km/h, and bring the train to an altitude of about 80 km above the ground. At the highest point of this journey, Branson and his colleagues will experience the feeling of weightlessness for a short time. The ship will then glide back to the surface.
The most valuable point of the flight is the time when the engines are off, VSS Unity and the passengers will be suspended in a state of microgravity. With a system of surrounding windows for a large view, even with a rear mirror, passengers can comfortably take pictures of space or take selfies while flying in the air.
When gliding back to the ground, the VSS Unity ship will use a system called feather – the wings will fold upwards, the ship looks like a badminton ball to help it navigate and slow down. After that, the ship’s wings will return to their original state and glide down the runway to land.
Feather is a unique system that is the most important but also the most dangerous safety feature for VSS Unity ships. Previously, when testing the SpaceShipTwo (SS2), pilot Michael Alsbury pushed the release lever too early, causing the ship to break. He was also the one who died in the accident 7 years ago, only one pilot survived but was seriously injured.