Planetary Exploration, 1968-1975: Report of a Study

analysis arc sec asteroids Astronomical biological bistatic bistatic radar chemical cloud composition density determination dynamics and interiors Earth Earth-based Earth-orbital telescopes etary exospheric experiments extraterrestrial feasible flight gases gravitational field ground-based High resolution imagery important infrared instrument interest interplanetary medium investigations ionosphere Jupiter Jupiter's knowledge lower atmosphere lunar Magnetometer major Mariner-class Mars and Venus Martian atmosphere Martian surface mass measurements Mercury Moon NASA near-space environment obtained opportunity orbiter mission origin particles periapsis photographs planetary atmospheres planetary dynamics planetary exploration planetary exploration program planetary magnetic field planetary missions planetary surface planning plasma possible present radar studies radiation radio occultation radiometer radiometry recommend that NASA regions relatively rotation satellites scientific scientists seismicity seismometer small planetary orbiters solar system solar wind solar wind interaction Soviet Space Science Board spacecraft spectroscopy surface of Venus terrestrial planets thermal tion understanding Venus and Mars Venus-Mercury fly-by