Linked here is a block diagram that illustrates how an interplanetary Space Flight System functions, using the Magellan spacecraft, which combined many of the subsystems discussed in this chapter. Magellan's mission succeeded in obtaining high resolution data from the entire surface of Venus in the early 1990's. The spacecraft carried only one science instrument, the Radar, to penetrate Venus's cloud cover. Otherwise, the spacecraft's subsystems are representative of those found on many other spacecraft. Boxes within the diagram are shown double or triple to indicate the presence of two or three units of the same name.
Components fail unexpectedly during the life of a mission.
Most components upon which the success of the mission depends have redundant backups, and the means to reroute functional flow to accommodate their use either autonomously or via commanding in real time. Ongoing research at JPL and other institutions is producing new technologies useful for less costly and more capable, more reliable and efficient spacecraft for future space missions. Advances in such areas as spacecraft power, propulsion, communications, navigation, data handling systems, pointing control and materials is expected to increase many times the potential science returns from future missions. Laser telecommunications systems are also being explored which modulate data onto beams of coherent light instead of radio. Among the advantages to laser telecommunications are low power consumption, much higher data rates, and reduced-aperture Earth stations.