Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

This publication presents the proceedings of ICPMSE-4, the fourth international conference on Protection of Materials and Structures from the Low Earth Orbit Space Environment, held in Toronto April 23-24, 1998. The conference was hosted and organized by Integrity Testing Laboratory Inc. (ITL), and held at the University ofToronto's Institute for Aerospace Studies (UTIAS). Twenty two industrial companies, six universities and fourteen government agencies from Canada, USA, United Kingdom, France, Israel, Russia, Ukraine and the Netherlands were represented by over 75 participants indicating increasing international co-operation in this critical arena of protection of materials in space. Twenty-seven speakers, world experts in their fields, delivered talks on a wide variety of topics on various aspects of material protection in space. Representatives from the Canadian, American, European and Israeli space agencies as well as from leading space research laboratories ofmajor aerospace industries gathered at UTIAS to discuss the latest developments in the field of material and structure protection from the harsh space environment.

Since the beginning of space flight, the collision hazard in Earth orbit has increased as the number of artificial objects orbiting the Earth has grown. Spacecraft performing communications, navigation, scientific, and other missions now share Earth orbit with spent rocket bodies, nonfunctional spacecraft, fragments from spacecraft breakups, and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft. Potential methods to protect spacecraft are explored. The report also takes a close look at the projected future growth in the debris population and evaluates approaches to reducing that growth. Orbital Debris offers clear recommendations for targeted research on the debris population, for methods to improve the protection of spacecraft, on methods to reduce the creation of debris in the future, and much more.