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 75 mm field gun and Battle of Okinawa, often deployed together with armored units. The Type 90 continued to be used as field artillery until the surrender of Japan. The Type 90 formed the basis for the Type 3 75 mm tank gun used in the Type 3 Ho-Ni III Gun tank and Type 3 Chi-Nu medium tank. Type 90 75 mm field gun The was a field gun used by the Imperial Japanese Army during the Second Sino-Japanese War, Soviet-Japanese Border Wars and World War II. The Type 90 designation was given to this gun as it was accepted in the year 2590