Forty-five years ago today — April 23, 1965 — the Soviet Union launched Molniya-1 on a Soyuz rocket from Baikonur.<\/p>\n
The satellite was placed in a very particular orbit: highly elliptical, with perigee (the lowest altitude) very close to the Earth’s southern hemisphere and apogee (the highest altitude) far above the northern hemisphere. By carefully selecting the angle of inclination (how “tilted” the orbital plane is from the equatorial plane), they produced a situation in which the satellite’s apparent motion over the northern hemisphere was very small, providing extended communications coverage in the polar regions where geosynchronous satellites could not.<\/p>\n
The orbit soon became known as a Molniya orbit, after the Molniya<\/a> satellites that were first inserted there. “Molniya,” itself, means “lightning.”<\/p>\n Here’s a wonderful YouTube video showing how the Molniya orbit works:<\/p>\n