Highly elliptical orbit Highly elliptical orbit A highly elliptical orbit (HEO) is an elliptic orbit with high eccentricity, usually referring to one around Earth. Examples of inclined HEO orbits include Molniya orbits, named after the Molniya Soviet communication satellites which used them, and tundra orbits. Such extremely elongated orbits have the advantage of long dwell times at a point in the sky during the approach to, and descent from, apogee. Bodies moving through the long apogee dwell appear to move slowly, and remain at high altitude over high-latitude ground sites for long periods of time. This makes these elliptical orbits useful for communications
Near-Earth Asteroid Scout mission researchers argue that "characterization of NEAs that are larger than 20 m in diameter is also of great relevance to inform mitigation strategies for planetary defense." The planned target, subject to change, is near-Earth object 1991 VG. 1991 VG was discovered shortly before passing just 0.003 AU from earth on 6 November 1991, and returned within 0.06 AU of Earth in August 2017. It raised interest due to the close approach, and the expectation that such an Earth-similar orbit would not have long term orbital stability. Once the flyby is complete, and if the system is still fully functioning,