SNAP TIMELINE

SNAP TIMELINE

1952 to 1955

The Atomic Energy Commission(AEC)* did an analysis of nuclear power sources and evaluated them on their feasibility to be used with future spacecraft.

1954

Specialized studies on nuclear-electric sources for space applications were done under the Pied Piper Program conducted in 1954(Ref. 2). These studies were later integrated into the Weapons Systems 117-L (WS 117-L) program, which conducted studies on a wide spectrum of energy and satellite systems for space.

1955

A joint AF-AEC committee established specifications for nuclear power in space. This included the power, life and interrelation of the nuclear device and spacecraft. The role of the AEC was to promote the development and utilization of atomic energy. The Pied Piper Program was later renamed the SNAP program.

A formal request for proposal studies was issued jointly by the

Department of Reactor Development (DRD) of the AEC and the Air Force Wright Air Development Center (AFWADC). AiResearch and Atomics International (AI) proposed a Zr-H reactor coupled to a Mercury-Rankine power conversion system. The early work was done independently by Lockheed Missiles and Space Division(LMSD) with Thompson Ramo Wooldridge (TRW) and AI with AiResearch of the Garrett Corporation. Funding was jointly sponsored by the AEC for the reactor development and the AF for work on the power conversion system (Ref. 3).

June 1957

AEC assumed complete control of the project and AI became

the prime contractor. TRW was contracted to complete work on the power conversion system and the research being completed by AiResearch was phased out completely by March 1958 (Ref. 3). Atomics International chose an epithermal reactor design for space applications over a fast reactor because the critical mass of a useful fast reactor would result in an uranium cost of the order of one million dollars (1961). For a reactor which was to be produced in quantity the resulting cost would have been greater than that of delivery into space when the launch costs fell below $1000 per pound (Ref. 4). Also, for temperatures between 315 to 10930C the Zr-H reactor was lighter than an

equivalent fast reactor.

October 1957

The first SNAP critical assembly was tested in October 1957, three weeks after Sputnik I was launched. The SNAP Experimental Reactor (SER) was operated in 1959 and the SNAP 2 Developmental Reactor (S2DR) in 1961. The SNAP 2 reactor had Zr-H fuel to be coupled with a Mercury-Rankine power conversion system. Table 1 is a compilation of SNAP reactor test experience and Table 2 outlines the development program.

1958

The AF requested Al to study a reactor designed with thermoelectric

conversion units.