| has gloss | eng: The beta angle - \boldsymbol\beta} - is a value that is used most notably in spaceflight. The beta angle determines the percentage of time an object such as a spacecraft in low Earth orbit (LEO) spends in direct sunlight, absorbing solar energy. Beta angle is defined as the angle between the orbit plane and the vector from the sun. The beta angle is the smaller angle (there are two angles) between the sun vector and the orbit plane. The beta angle varies between +90° and -90°. Satellite revolution determines the beta angle sign. Looking from the Sun, the beta angle is positive if the satellite is revolving counter clockwise and negative if revolving clockwise. Note that the beta angle does not define a unique orbit plane, but for a given beta angle and a given altitude, all beta angle orbits have the same exposure to the sun. The percent sunlight does not fall below 59% for normal low Earth orbit missions. |
