FLYING THE COSMIC GIRL

摘要

Earlier in 2021,10 cubesats - small, cheap satellites weighing about a kilogram each - were sent into orbit around Earth. With almost 1,500 of these small satellites launched so far, adding another 10 might seem trivial. But this was no ordinary launch. Instead of lifting off from the ground, the rocket carrying these National Aeronautics and Space Administration (NASA) satellites was slung under the wing of a modified Boeing 747, called Cosmic Girl. The plane carried them to a height of 11km (6.8 miles) before launching the rocket.This milestone was the first successful launch of Virgin Orbit's LauncherOne rocket, marking the start of its commercial ventures. The company hopes to provide cheap, flexible satellite launching services, without the need to use sites on the ground.Usually, a rocket launched from a launch site on the ground will have two or three stages, which allow the rocket to shed weight as it uses up fuel. The first stage is the part which ignites at launch, powering the rocket from the ground. When the rocket reaches a certain altitude, the first stage then separates, leaving the second to ignite. A third stage operates on the same principle and typically places the payload - the part we want to get into space - in its final orbit or interplanetary trajectory.When satellites are launched from a plane, the carrier aircraft functions as both a launch site and a reusable first stage of the rocket.Aircraft are more efficient than rockets at getting off the ground, but they cannot function without an atmosphere to generate aerodynamic lift. Air-launching takes advantage of this by attaching a rocket to an aircraft and releasing it at high altitude.