Magellan missionRadar sensing and image interpretation Essay

Magellan missionRadar sensing and image interpretation - Essay Example The Mission was named after Ferdinand Magellan, a Portuguese-born explorer in the sixteenth century, who led an expedition that first circumnavigated the Earth. The earlier radar missions to Venus provided planetary scientist a global map of the surface of the planet and were very valuable in understanding the geological structure of the planet. However it further revealed a need for "global radar data coverage" of the planet's surface in "orders-of magnitude higher resolution" (Ford 1). This need facilitated and provided motivation to determine the design and objectives of the Magellan mission. The main purposes of the Magellan Mission were to create a global radar map of the surface of Venus at higher resolution using the synthetic aperture radar (SAR) and to determine the topographic relief of the planet. The end product of these four objectives shall be the classification of geographic and tectonic features of the surface like mountains, ridges, valleys, hills, and planes. Impact processes, lava flows, and other chemical processes will be explained and the internal density distribution of the planet will be modeled. The spacecraft design was economical and simple in relation to other spacecraft missions. In fact, the key components of the spacecraft were acquired from the spare hardware from other space programs including Voyager, Galileo, Viking, and Mariner. The spacecraft was 6.4 m long and with a mass of 3,449 kilograms. Included in the spacecraft were a single radar sensor, a large 3.7-m diameter parabolic High-Gain Antenna dish used for communication with Earth and a science instrument for radar imaging, solar panels about 9.2 m across to collect solar energy for charging the spacecraft's nickel-cadmium batteries and to power the spacecraft, three orthogonal reaction wheels used for pointing control, monopropellant hydrazine thruster system used to make adjustments of large scale orbital corrections. Subsystems included a medium-gain antenna, star scanner, on-board computer, coherent X- and S- band radio subsystem used for communication and gravity field experiments, and two tape recorders. Fig. 1. Labeled drawing of Magellan Spacecraft Key features of the Magellan spacecraft. Shown here are the different hardware and electronic subsystems of the spacecraft. (NASA) The Magellan spacecraft in the payload bay of the Space Shuttle Atlantis before its scheduled launch (Magellan Probe). Fig. 2. Magellan Spacecraft The Magellan Radar Sensor The radar sensor is a single science instrument in the spacecraft capable of acquiring data in three different modes or functions: SAR imaging mode,