Atomic Propulsion, the science of moving

In the early days of nuclear power things was optimistic on the uses of this technology, crazy experiments include the firing of an atom bomb above the heads of human observers. A large cannon to fire nuclear bombs and of course Atomic powered engines for submarines large boats and Airplanes. The idea of making atom cars powered by uranium-235 dated back to at least 1941 when Dr R M Langer, a CalTech physicist, espoused the idea in the January edition of Popular Mechanics. He was followed by William Bushnell Stout, designer of the Stout Scarab and former Society of Engineers President, on 7 August 1945 in the New York Times. By 1951 the problem of shielding the reactor had rendered the idea impractical.

Naval reactors undergo repeated power changes for ship maneuvering, unlike civilian counterparts which operate at steady state. Nuclear safety, radiation, shock, quieting, and operating performance requirements in addition to operation in close proximity to the crew dictate exceptionally high standards for component manufacturing and quality assurance. The internals of a Naval reactor remain inaccessible for inspection or replacement throughout a long core life -- unlike a typical commercial nuclear reactor, which is opened for refueling roughly every eighteen months.


Nuclear jet engines was the heart of propulsion system for a new type of long distance bomber. There were two types of systems competing for the potential contract of the new bomber. The direct Cycle nuclear engine designs were proposed in the late 40s by the same people who worked on atomic bomb designs. Direct cycle nuclear engines would resemble a conventional engine, except that there would be no combustion chambers. The air gained from the compressor section would be sent to a plenum that directs the air into the nuclear reactor core. An exchange takes place where the reactor is cooled, but it then heats up the same air and sends it to another plenum. The second plenum directs the air into a turbine, which sends it out the exhaust. The end result is that instead of using jet fuel, an aircraft could rely on chemical reactions for power.
Another proposed design utilized an indirect cycling method to utilize nuclear heat for thrust. Indirect cycling involved thermal exchange outside of the core. The compressor air would be sent to a heat exchanger. The nuclear reactor core would heat up pressurized water or liquid metal and send it to the heat exchanger as well. That hot liquid would be cooled by the air; the air would be heated by the liquid and sent to the turbine. The turbine would send the air out the exhaust, providing thrust.

Several experimental aircraft were created and launched with both the indirect and direct cycle engines.

An NB-36 made nearly 50 record-setting flights between 1956 and 1957, according to aircraft historian Raul Colon's article "Flying on Nuclear, The American Effort to Built a Nuclear Powered Bomber." However, the Air Force scrapped any future plans due to public concern over nuclear engines in the air and better-designed conventional engines.

Project Orion was a study of a spacecraft intended to be directly propelled by a series of explosions of atomic bombs behind the craft (nuclear pulse propulsion). Early versions of this vehicle were proposed to have taken off from the ground with significant associated nuclear fallout; later versions were presented for use only in space. The Orion nuclear pulse drive combines a very high exhaust velocity, from 12 to 19 mi/s (19 to 31 km/s) in typical interplanetary designs, with mega-newtons of thrust. The craft would be propelled by pulsed explosions, the craft it self would have a protective shielding which would ensure a relatively safe environment. The shielded side would include a shock absorbing pusher plate.
Exposure to repeated nuclear blasts raises the problem of ablation (erosion) of the pusher plate. However, calculations and experiments indicate that a steel pusher plate would ablate less than 1 mm if unprotected. If sprayed with an oil, it need not ablate at all (this was discovered by accident; a test plate had oily fingerprints on it, and the fingerprints suffered no ablation). The absorption spectra of carbon and hydrogen minimize heating. Supporters of Project Orion felt that it had potential for cheap interplanetary travel, but it lost political approval over concerns with fallout from its propulsion. The Partial Test Ban Treaty of 1963 is generally acknowledged to have ended the project.

Theoretically the nuclear propulsion systems of the past might have advanced Air travel. Although its use of direct nuclear heat to provide the energy for a jet engine might have irradiated the air, causing possible environmental dangers. Nuclear power have been successfully installed in submarines and aircraft carriers, so why not airplanes?. Radiation shielding in light aircraft has been a major problem as conventional lead shielding is always heavy, also the thrust capacity provided was minimal at best. Considering these negative factors are problems of the past and new materials in metrology and electronics. I am convinced that an nuclear power converted to electrical power could provide a better indirect system to provide a heat source.
The same heat that could provide a jet engine its power or even a faster efficient ram jet, which could possibly take the craft to fly to the edge of space several times the speed of sound. Also the next generation of plasma ion propulsion engine, which uses a lot of electrical power can provide a working alternative to traditional space rockets. The slow change to move away from fossil fuels and crude oil will probably delay the technology of nuclear power. Public confidence in Atomic power has been an all time low due to the inferior pressured water reactor. Despite our current nuclear reactors there are relatively safe alternatives, politics had put a stop to this technology and kept it in the early stages round the era of the cold war. Eventually when people have the money and resources, they might think differently to nuclear propulsion systems. India and china have already expressed interest in thorium reactors, which seem the best solution to the power crisis. It might be a matter of time to merge old and new technologies to mobile setting, hopefully within my own timeline.

The hidden history of Atomic Airplanes

In the late 1940s, as the Cold War began to heat-up, the Soviet Union began research into the development of nuclear reactors as power sources to drive warships. The problem with most fighter planes and military aircraft was that all of them had limited range. Some of the earliest experiments in aerial refueling took place in the 1920s; two slow-flying aircraft flew in formation, with a hose run down from a hand-held fuel tank on one aircraft and placed into the usual fuel filler of the other. The first mid-air refueling between two planes occurred on June 27, 1923.
Though possible, inflight refueling was impractical in the pre jet era due to weight issues and inferior power from propeller engines. World war two was fought with out a inflight fuel system. US Bombers B17 and B24 was generally massacred over Germany because fighter escorts simply could not fly that far. The fighter plane mustangs later reduced losses because they were equipped with extra fuel tanks. The flight operation range was a constant concern for the military and that include improvements to planes.
The lockheed P38 lighting was commissioned in 1937 and was  used as a long range interceptor fighter to fly over the Pacific. I when it entered into service in 1941 the Lighting had a range of 700 km or 435 miles. The B29 super fortress was later introduced in 1944, it had a range of 4.500 Km or 2796 miles. it was capable of bombing japan from island aircraft bases. Much of the aviation technology during the wars filtered down to commercial planes which made long distance flight possible.

The emergence of the cold war brought about the plans to commission a long range bomber to reach the heart of Russia. The idea to have a bomber with an unlimited amount of energy to fly possibly on long standby duties to circle around in case of nuclear threat.
General Cirtis LeMay headed a program called N.E.P.A The Nuclear Energy Propulsion of Aircraft in 1946. This was a program to oversee the possibility of designing and building a nuclear powered bomber. Progress was slow, NEPA was replaced by the Aircraft Nuclear Propulsion (ANP) program in May 1951. The ANP program included provisions for studying two different types of nuclear-powered jet engines, General Electric's Direct Air Cycle and Pratt & Whitney's Indirect Air Cycle. ANP also contained plans for two B-36s to be modified by Convair under the MX-1589 project, one of the B-36s was to be used to study shielding requirements for an airborne reactor while the other was to be the X-6. The program was cancelled before the X-6 was completed, however. The first operation of an aircraft engine on nuclear power was achieved on January 31, 1956 using a modified General Electric J47 turbojet engine. The Aircraft Nuclear Propulsion program was terminated following the President's annual budget message to Congress in 1961.

The Oak Ridge National Laboratory conducted research (Aircraft Reactor Experiment) to produce a nuclear powered aircraft. Two General Electric turbofan engines were successfully powered to nearly full thrust using two shielded reactors. The two engines complete with reactor system are currently located at the EBR-1 facility south of the Idaho National Laboratory. The U.S. designed these engines to be used in a new specially designed nuclear bomber, the WS-125, which was eventually terminated by Eisenhower who cut NEPA and told Congress that there was no urgency for the program. Eisenhower did back a small scale program developing high temperature materials and high performance reactors. That program was terminated early in the Kennedy administration.
In 1957, the Air Force and the U.S. Atomic Energy Commission contracted with the Lawrence Radiation Laboratory to study the feasibility of applying heat from nuclear reactors to ramjet engines. This research became known as Project Pluto. The engines being developed under this program were intended to power an unmanned cruise missile, called SLAM, for Supersonic Low Altitude Missile. The program succeeded in producing two test engines which were operated on the ground. On May 14, 1961, the world's first nuclear ramjet engine, "Tory-IIA," mounted on a railroad car, roared to life for just a few seconds. On July 1, 1964, seven years and six months after it was born, "Project Pluto" was cancelled.

The Soviet program of developing nuclear aircraft resulted in the experimental Tupolev Tu-119, also known as the Tu-95LAL (LAL- Летающая Атомная Лаборатория- Flying Nuclear Laboratory). It was based on a Tupolev Tu-95 bomber. It had 4 conventional turboprop engines and an onboard nuclear reactor. The Tu-119 completed 34 research flights. Most of these were made with the reactor shut down.

The main purpose of the flight phase was examining the effectiveness of the radiation shielding which was one of the main concerns for the engineers. Massive amounts of protection used resulted in radiation levels low enough to consider continuing development. But, as in the US, development never continued past this point. The obvious potential of the ICBM made the expensive program superfluous, and around the mid 1960s it was cancelled.

The near threat of nuclear war brought about changes in using nuclear powered vehicles. Since the nuclear test ban treaty signed by Kennedy and Khrushchev, no advancement has ben made for Atomic airplanes. Yet nuclear powered submarines and aircraft-carriers are still thriving today. Advances in technology, material science and production could potentially reboot the idea of nuclear powered flight. Especially when fossil fuels runs out and jet engines will become useless relics. The need for alternative power maybe on the horizon, though the use of heavy lead shielding have proven to be difficult on aircraft. I mentioned before how electrical power could power the next generation of Ion engines for high speed space travel, this idea of atomic aviation seems like a natural stepping stone for greater things...