Engineering topics
Publications and source records attributed to Melton, Robert G..
Papers from the third annual Spaceflight Mechanics Meeting are presented. The topics covered include the following: attitude dynamics and control; large flexible structures; intercept and rendezvous; rendezvous and orbit transfer; and trajectory optimization.
An account is given of the NASA/USRA Advanced Design Program (ADP) instituted by Penn State for students in space-related fields. ADP class instruction is structured in such a way as to simulate the working environment in which design engineers from different disciplines must interact, at various levels, in the course of defining a spacecraft-related system. Student groups are assigned a mission objective, for which they are to complete a preliminary design encompassing all aspects of the mission from launch to recovery. Two major writen reports are required from each group.
During the 1991-92 academic year, the Pennsylvania State University has developed three sample return missions: one to the nucleus of comet Wild 2, one to the asteroid Eros, and one to three asteroids located in the Main Belt. The primary objective of the comet nucleus sample return mission is to rendezvous with a short period comet and acquire a 10 kg sample for return to Earth. Upon rendezvous with the comet, a tethered coring and sampler drill will contact the surface and extract a two-meter core sample from the target site. Before the spacecraft returns to Earth, a monitoring penetrator containing scientific instruments will be deployed for gathering long-term data about the comet. A single asteroid sample return mission to the asteroid 433 Eros (chosen for proximity and launch opportunities) will extract a sample from the asteroid surface for return to Earth. To limit overall mission cost, most of the mission design uses current technologies, except the sampler drill design. The multiple asteroid sample return mission could best be characterized through its use of future technology including an optical communications system, a nuclear power reactor, and a low-thrust propulsion system. A low-thrust trajectory optimization code (QuickTop 2) obtained from the NASA LeRC helped in planning the size of major subsystem components, as well as the trajectory between targets.