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 Object Camera Near-Earth Object Camera The Near-Earth Object Camera (NEOCam) is a proposed space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids. NEOCam would survey from the Sun–Earth Lagrange point, allowing it to look close to the Sun and see objects inside Earth's orbit. NEOCam would be a successor to the WISE mission; the principal investigator is also WISE's principal investigator, Amy Mainzer of NASA Jet Propulsion Laboratory. Proposals for NEOCam were submitted in 2006, 2010, and 2015 to the NASA Discovery Program, but it has not been selected for launch. The primary scientific goal of NEOCam is