英和和英

出典:『Wikipedia』 (2011/05/19 16:49 UTC 版)

英語による解説

引用

A gravity turn or zero-lift turn is a maneuver (see trajectory optimization) used in launching a spacecraft into, or descending from, an orbit around a celestial body such as a planet or a moon. This launch trajectory offers two main advantages over a thrust-controlled trajectory where the rocket's own thrust steers the vehicle. First, any thrust used to change the ship's direction does not accelerate the vehicle into orbit. This loss can be reduced by using gravity to steer the vehicle onto its desired trajectory. Second, and more importantly, because gravity does the steering during the initial ascent phase the vehicle can maintain low or even zero angle of attack. This minimizes transverse aerodynamic stress on the launch vehicle, allowing for a lighter launch vehicle.