Nuclear Rocket Program Research Articles

Science in flux: NASA's nuclear program at Plum Brook Station, 1955-2005

Science in Flux traces the history of one of the most powerful nuclear test reactors in the United States and the only nuclear facility ever built by NASA. In the late 1950's NASA constructed Plum Brook Station on a vast tract of undeveloped land near Sandusky, Ohio. Once fully operational in 1963, it supported basic research for NASA's nuclear rocket program (NERVA). Plum Brook represents a significant, if largely forgotten, story of nuclear research, political change, and the professional culture of the scientists and engineers who devoted their lives to construct and operate the facility. In 1973, after only a decade of research, the government shut Plum Brook down before many of its experiments could be completed. Even the valiant attempt to redefine the reactor as an environmental analysis tool failed, and the facility went silent. The reactors lay in costly, but quiet standby for nearly a quarter-century before the Nuclear Regulatory Commission decided to decommission the reactors and clean up the site. The history of Plum Brook reveals the perils and potentials of that nuclear technology. As NASA, Congress, and space enthusiasts all begin looking once again at the nuclear option for sending humans to Mars, the echoes of Plum Brook's past will resonate with current policy and space initiatives.

Nuclear rocket safety

A renewed interest in lunar and Mars exploration and the expanded development of Earth orbiting satellites have resulted in a new interest in nuclear rockets. Well thought-out U.S. and U.N. policies exist for the use of nuclear reactors in space. Guidelines for space reactors have been prepared by DOE and NASA in recent years, and a safety review and approval process is in place. A review of the nuclear rocket program (Rover/NERVA) that was carried on from the mid-fifties until 1973 leads to the philosophy that flight safety considerations should start with the design process and provide solutions that are built into the design. The program resulted in very detailed specifications and criteria for the safe use of rocket reactors. Design practices and an extensive experience base that is still applicable today were developed. This technology base provides important information to be used in any future nuclear rocket as well as the confidence that nuclear rockets can be safely developed for future space missions.

Transversely excited submillimeter-wave waveguide laser

Gaseous core reactors and nuclear pumped lasers have the potentials of space propulsion at exhaust jet velocities up to 50,000 m/sec, space power at 1 kg/kW specific mass, power transmission via laser beams over astronomical distances and beneficial applications on Earth.The energization of lasers directly by nuclear reactions has recently been achieved. In experiments conducted jointly by the University of Florida and the Los Alamos Scientific Laboratory, New Mexico, a helium-xenon laser was directly pumped by fission fragments. The obtained laser wavelength was 3.5 μm. A group of researchers at the Sandia Corporation in Albuquerque, New Mexico, was successful in energizing a carbon monoxide laser by fission fragments at wavelengths in the 5-μm band. At the University of Illinois lasing was achieved at wavelengths of 8629 Å and 9393 Å in a neon-nitrogen mixture. A program of gaseous core reactor research is underway with experiments being conducted at the Los Alamos Scientific Laboratory in New Mexico, USA. The program utilizes a beryllium moderator-reflector, forming a cylindrical cavity of 1 m diameter and 1 m length. This system and associated control system hardware, uses components from the previous ROVER nuclear rocket program. Various configurations of canisters containing enriched gaseous uraniumhexafluoride fuel are inserted into the reactor cavity for research on neutronics and nuclear induced optical radiation.Critical mass, control swing and the effects of poison were measured by simulating enriched uranium hexafluoride fuel with uranium foils, which were placed in homogenous and inhomogeneous distributions in the cavity. Critical mass was determined at about 6 kg 93% enriched 235 uranium. A uranium hexafluoride canister system was built for safe operation in the reactor cavity and for physics measurements and observations at nuclear criticality.It is anticipated that this work will result in the demonstration of principles of a new type of nuclear power reactor, and of laser power output from such a reactor.

The nuclear rocket program - Its status and plans.

The second SPAROAIR III flight-test vechicle was launched on May 26, 1966. Aircraft separation, first-stage operation, coast, and second-stage ignition appeared normal. However, approximately 6 sec after second-stage ignition all telemetry signal was lost, and all radar operators reported explosion of the vehicle. Examination and reduction of the telemetry data indicated that during the entire period of second-stage operation the chamber pressure was ~75% above predicted values, although the curve was of the predicted form. Examinations of the trace for the solar-aspect cell showed that the mechanical arming-and-firing mechanism functioned as anticipated by arming and firing 0.25 and 2.0 sec, respectively, after first-stage ignition. Additional analysis of this trace shows that there was essentially no roll until shortly after first-stage burnout. The abrupt increase in roll rate after burnout was probably due to the loss of the roll damping provided by the first-stage fins, and indicates that the stages drag-separated as planned. Calculations indicated that the increase in the propellant's burning surface necessary to provide the high chamber pressures would have to result from severe grain cracking, most probably in the star points. The fact that the motor withstood 105 kg/cm at ignition, but burst 6 seconds later at 56 kg/cm, indicates that a propellant burnthrough occurred. Examination of the history of this second-stage motor shows that it was 2 years old when launched, beyond the normal shelf life for this propellant, and the environmental conditions and handling history at NAVMISCEN during storage could not be established. Therefore age, rather than any basic defect, is believed to have been the failure cause. Further flight-test verification and vehicle utilization are under consideration. Although the performance capabilities shown in Fig. 7 have not been totally confirmed by flight test, the flight-test program has provided sufficient confirmation of the basic assumptions (weights, launch conditions, and drag coefficients) that were used in these calculations to show them to be realistic values.

The Rover Nuclear Rocket Program

The Rover Nuclear Rocket Program

Review of Solid Core Nuclear Rockets

This paper describes briefly the programs underway to develop solid-core reactor technology for nuclear rockets. Recent successful KIWI and NERVA reactors have shown great progress in the development of graphite reactor technology and provide a sound basis for the ultimate development of nuclear rocket engines for a variety of space missions. In addition to the reactor work, this discussion presents the efforts in the Nuclear Rocket Program for development of nonreactor components, systems studies and research, and full nuclear rocket engine systems tests (to be conducted in the next 2 or 3 years) to provide the overall technology required for application of solid-core nuclear rocket engines to missions.