@conference {2331, title = {2331. Ballast - A Necessary Evil Few Want to Talk About}, booktitle = {55th Annual Conference, Atlanta, Georgia, June 3-5}, year = {1996}, month = {6/3/96}, pages = {10}, publisher = {Society of Allied Weight Engineers, Inc.}, organization = {Society of Allied Weight Engineers, Inc.}, type = {18. WEIGHT ENGINEERING - SPACECRAFT DESIGN}, address = {Atlanta, Georgia}, abstract = {Ballast has been used in practically every type of land, sea, air, or space vehicle. It is {\textquoteright}enabling{\textquoteright} providing stability and trim through adjustment of the distribution of mass. The NASA shuttle is most frequently ballasted to rectify a forward center-of-gravity condition. The various types and locations of ballast on various types of vehicles are discussed. The propulsive efficiency of most vehicles can be improved by reducing the amount of ballast carried, but practical considerations, such as the stability in roll (for a ship) places limitations on this method for improving efficiency. In accepting reduced, or even negative, stability margins some aircraft achieve weight reduction, but artificial stability, in the form of active controls, must be employed. Ballasting can be avoided in many cases by good weights management early in any project.}, keywords = {18. Weight Engineering - Spacecraft Design}, url = {https://www.sawe.org/papers/2331/buy}, author = {MacConochie, Ian O.} }