power systems for space and national security applications, for Cassini RTG production, for development of the SP-100 space nuclear reactor, and for several classified programs. He initiated technical development of new energy conversion technologies for space and terrestrial applications. During 2002, Mr. Newhouse was a consultant to NASA’s Office of Space Science on the Nuclear System Initiative (later Project Prometheus). In 2003 he joined NASA and was in charge of Project Prometheus. In late 2004 he was appointed as the Program Executive for Radioisotope Power Systems in the Science Mission Directorate and as a senior technical advisor to the Development Division of NASA’s Exploration Systems Directorate. He retired again from government service at the end of 2004.

JOSEPH A. SHOLTIS, JR., Lt Col, USAF (retired), is a nuclear and aerospace engineer with 38 years of experience with advanced nuclear systems and programs for a variety of applications. Areas of particular focus include space and advanced terrestrial nuclear systems and their safety, and risk assessment of space missions employing nuclear systems or materials, including preparation and delivery of formal studies and analyses to middle and top management in the Department of Defense (DoD), Department of Energy (DOE), NASA, the U.S. Nuclear Regulatory Commission, the Environmental Protection Agency (EPA), the White House, and Congress. Mr. Sholtis is the owner and principal consultant of Sholtis Engineering and Safety Consulting. Current and prior customers include Sandia National Laboratories, Rocketdyne, the Jet Propulsion Laboratory, Los Alamos National Laboratory, the New Mexico Office of Space Commercialization, and the joint DoD, DOE, NASA, EPA, and Nuclear Regulatory Commission Interagency Nuclear Safety Review Panel. Areas currently being investigated include Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) safety, Mars Science Laboratory mission risk, as well as assessment and advancement of coated particle fuel for future radioisotope power systems. During his career, Mr. Sholtis has worked at Sandia National Laboratories (on advanced reactors), the Defense Nuclear Agency (on research and test reactors and radiation sources), and DOE Headquarters (on the joint DOE/DoD/NASA SP-100 Space Reactor Power System Development Program). He has been involved in the nuclear safety and risk assessment of every U.S. nuclear-powered space mission launched since 1974; i.e., Viking 1 and 2, Lincoln Experimental Satellites (LES) 8 and 9, Voyager 1 and 2, Galileo, Ulysses, Mars Pathfinder, Cassini, Mars Exploration Rover (MER) A and B, and Pluto-New Horizons.

SPENCER R. TITLEY (NAE) is a professor in the Department of Geosciences at the University of Arizona. He previously worked on NASA’s Lunar Orbiter program and was also a member of the Apollo Field Geology Investigation Team, serving on Apollo missions 16 and 17. His current research involves the study of the origin of mineral deposits and the distribution and location of mineral and mineral fuel resources. His research has also included the study of chemical baselines of trace elements in rocks and ores for environmental purpose.

EMANUEL TWARD is a consultant to Northrop Grumman Space Technology, an organization from which he retired in 2006. At the time, he was the cryogenics business area manager and project manager for a number of flight cryocooler development projects (13 in orbit) and for development of a thermoacoustic Stirling power converter. Dr. Tward has also worked at the Jet Propulsion Laboratory’s Low Temperature Physics Group, where he was active in the development of long-lived cryocoolers for spacecraft. Dr. Tward was previously an associate professor of physics at the University of Regina, where he was developing a gravitational wave detector.

EARL WAHLQUIST worked in the Radioisotope Power System program for the Department of Energy for more than 20 years, and he was the program director for the program for the last 8 years before he retired in 2006. In that role Mr. Wahlquist managed the development of the RTG for the Pluto spacecraft that was launched in 2006. This included responsibility for the contractors producing the RTG and the DOE facilities and infrastructure that processed the 238Pu into heat sources and assembled the heat sources into the generators. It also included directing the review and assurance of the safety of the systems, including interfacing with the interagency review group that independently reviews the safety. Mr. Wahlquist also managed efforts to centralize all of the DOE RTG processing and assembling facilities at a single location. He also directed several studies looking at either purchasing 238Pu from foreign sources or producing the material within the United States.


ALAN C. ANGLEMAN, Study Director, has been a senior program officer for the Aeronautics and Space Engineering Board (ASEB) since 1993, directing studies on a wide variety of aerospace issues. Previously, Mr. Angleman worked for consulting firms in the Washington, D.C., area providing engineering support services to the Department of Defense and NASA Headquarters. His professional career began with the U.S. Navy, where he served for nine years as a nuclear-trained submarine officer. He has a B.S. in engineering physics from the U.S. Naval Academy and an M.S. in applied physics from the Johns Hopkins University.

DWAYNE A. DAY, a program officer for the Space Studies Board (SSB), has a Ph.D. in political science from the George Washington University and has previously served as an investigator for the Columbia Accident Investigation

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