Beta angle in the Earth's shadow, and results in extremely reduced absorption of solar energy. At a LEO of 280 kilometers, the object is in sunlight through 59% of its orbit (approximately 53 minutes in Sunlight, and 37 minutes in shadow.) On the other extreme, an object launched into an orbit parallel to the terminator results in a beta angle of 90 degrees (formula_2 = 90°), and the object is in sunlight 100% of the time. An example would be a polar orbit initiated at local dawn or dusk on an equinox. Beta angle can be controlled to keep a satellite as
Type 90 AFV Type 90 AFV The Type 90 is an armoured fighting vehicle produced by Chinese company Norinco; it is the successor for the Type 85 AFV of which it uses some components. The Type 90 series was developed for export, and consists of at least 10 different types; its industrial index is YW535. This new type is rather similar to its predecessors Type 85 AFV and Type 89 AFV, but the hull has a different shape, having a vertical lower side wall and a sloping upper side wall. Overall, the Type 90 is bigger and heavier, yet has a lower profile.