Highly Elliptical Orbit (HEO)

Highly Elliptical Orbits — the Molniya and Tundra families being the classic examples — are tuned so the satellite spends most of its orbit dwelling over a specific high-latitude region. Russia pioneered these orbits because GEO is useless from high latitudes; Molniya satellites give Russia and Canada GEO-equivalent communications coverage.

Common uses: high-latitude communications, signals intelligence, early warning