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Flight dynamics calculations are handled by computerized guidance systems aboard the vehicle; the status of the flight dynamics is monitored on the ground during powered maneuvers by a member of the flight controller team known in NASA's Human Spaceflight Center as the flight dynamics officer, or in the European Space Agency as the spacecraft ...
A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collection and subsequent interpretation of data, so that the heating and cooling effects of sunlight and shadow ...
and are the masses of objects 1 and 2, and is the specific angular momentum of object 2 with respect to object 1. The parameter θ {\displaystyle \theta } is known as the true anomaly , p {\displaystyle p} is the semi-latus rectum , while e {\displaystyle e} is the orbital eccentricity , all obtainable from the various forms of the six ...
Delta-v (also known as "change in velocity"), symbolized as and pronounced /dɛltə viː/, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver.
The guidance program is a precalculated lookup table of pitch vs time. Control is done with engine gimballing and/or aerodynamic control surfaces. The pitch program maintains a zero angle of attack (the definition of a gravity turn) until the vacuum of space is reached, thus minimizing lateral aerodynamic loads on the vehicle.
Figure 1: Approximation of a finite thrust maneuver with an impulsive change in velocity. An impulsive maneuver is the mathematical model of a maneuver as an instantaneous change in the spacecraft's velocity (magnitude and/or direction) [3] as illustrated in figure 1. It is the limit case of a burn to generate a particular amount of delta-v, as ...
The eight rotational control engines were mounted off the spacecraft's center of mass around the aft section of the Equipment Module, pointed at 90 degree positions up, down, left and right. These were rated at 25 pounds-force (110 N) thrust and fired in pairs, causing it to yaw, pitch, or roll to control attitude.
The slew of a spacecraft is its orientation in reference to a plane or fixed position such as Earth, the Sun, another celestial body or other point in space. When moving to assume such an orientation, the spacecraft is slewing. [1] [2] [3] During spaceflight, a craft's attitude must be controlled for reasons depending on the craft's mission ...