This Final Supplemental Environmental Impact Statement (FSEIS) to the 1995 Cassini mission Environmental Impact Statement (EIS) focuses on information recently made available from updated mission safety analyses. This information is pertinent to the consequence and risk analyses of potential accidents during the launch and cruise phases of the mission that were addressed in the EIS. The type of accidents evaluated are those which could potentially result in a release of plutonium dioxide from the three Radioisotope Thermoelectric Generators (RTGS) and the up to 129 Radioisotope Heater Units (RHUS) onboard the Cassini spacecraft. The RTGs use the heat of decay of plutonium dioxide to generate electric power for the spacecraft and instruments. The RHUs, each of which contains a small amount of plutonium dioxide, provide heat for controlling the thermal environment of the spacecraft and several of its instruments. The planned Cassini mission is an international cooperative effort of the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Italian Space Agency (ASI) to conduct a 4-year scientific exploration of the planet Saturn, its atmosphere, moons, rings, and magnetosphere. Unspecified Center NASA/TM-1997-111474/SUPPL1, NAS 1.15:111474/SUPPL1 ...

The purpose of this environmental impact statement (EIS) is to provide information on potential environmental impacts that could result from a Proposed Action to construct, operate and monitor, and eventually close a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nye County, Nevada. The EIS also provides information on potential environmental impacts from an alternative referred to as the No-Action Alternative, under which there would be no development of a geologic repository at Yucca Mountain.

"Exploring the unknown" is a multi-volume series containing a selection of key documents in the history of the U.S. civil space program. Volume V, focusing on the exploration of space by robotic spacecraft that have significantly altered our perspectives on the cosmos, prints 121 key documents on the history of space science, planetary exploration of the solar system, and space astrophysics, edited for ease of use. Many of these documents are published here for the first time. Each is introduced by a headnote providing context, bibliographical information, and background information necessary to understanding the document. This documentary history is an essential reference for anyone interested in the history of the U.S. civil space program and its development over time. It will serve as a valuable source both for students and scholars. Additional volumes will appear later that trace space science and the programmatic developments in the history of the U.S. exploration of space.