Civil engineering and energy production formed a crater 100m (330 ft) deep with a diameter of about 390m (1,300 ft) as a means of investigating the possibilities of using peaceful nuclear explosions for large-scale earth moving. If this test was conducted in 1965, when improvements in device design were realized, a 100-fold reduction in radiation release was considered feasible. The 140kt Soviet
Chagan (nuclear test), comparable in yield to the Sedan test of 104kt, formed
Lake Chagan, reportedly used as a watering hole for
cattle and human swimming. Apart from their use as weapons,
nuclear explosives have been tested and used, in a similar manner to chemical
high explosives, for various non-military uses. These have included large-scale earth moving,
isotope production and the stimulation and closing-off of the flow of
natural gas. At the peak of the
Atomic Age, the United States initiated
Operation Plowshare, involving "peaceful nuclear explosions". The
United States Atomic Energy Commission chairman announced that the Plowshare project was intended to "highlight the peaceful applications of nuclear explosive devices and thereby create a climate of world opinion that is more favorable to weapons development and tests". The Operation Plowshare program included 27 nuclear tests designed towards investigating these non-weapon uses from 1961 through 1973. Due to the inability of the U.S. physicists to reduce the fission fraction of low-yield (approximately 1 kiloton) nuclear devices that would have been required for many
civil engineering projects, when long-term health and clean-up costs from
fission products were included in the cost, there was virtually no economic advantage over conventional explosives except for potentially the very largest projects. and/or canal route from the
Mediterranean Sea to the
Qattara Depression.No route was shorter than 55
kilometers in length. Canal-cutting investigations began with
the buggy salvo shot of Operation Crosstie in 1967. The
Qattara Depression Project was developed by Professor
Friedrich Bassler during his appointment to the West German ministry of economics in 1968. He put forth a plan to create a Saharan lake and
hydroelectric power station by blasting a tunnel between the
Mediterranean Sea and the
Qattara Depression in Egypt, an area that lies below sea level. The core problem of the entire project was the water supply to the depression. Calculations by Bassler showed that digging a canal or tunnel would be too expensive, therefore Bassler determined that the use of nuclear explosive devices, to excavate the canal or tunnel, would be the most economical. The Egyptian government declined to pursue the idea. The
Soviet Union conducted a much more exhaustive program than Plowshare, with 239 nuclear tests between 1965 and 1988. Furthermore, many of the "tests" were considered economic applications, not tests, in the
Nuclear Explosions for the National Economy program. These included a 30-kiloton explosion being used to close the
Uzbekistani
Urtabulak gas well in 1966 that had been blowing since 1963, and a few months later a 47-kiloton explosive was used to seal a higher-pressure blowout at the nearby
Pamuk gas field. (For more details, see Blowout (well drilling)#Use of nuclear explosions.) Devices that produced the highest proportion of their yield via fusion-only reactions are possibly the
Taiga Soviet peaceful nuclear explosions of the 1970s. Their public records indicate 98% of their 15 kiloton explosive yield was derived from fusion reactions, so only 0.3 kiloton was derived from fission. The repeated detonation of nuclear devices underground in
salt domes, in a somewhat analogous manner to the explosions that power a car's
internal combustion engine (in that it would be a
heat engine), has also been proposed as a means of
fusion power in what is termed
PACER. Other investigated uses for low-yield peaceful nuclear explosions were underground detonations to stimulate, by a process analogous to
fracking, the flow of
petroleum and
natural gas in
tight formations; this was developed most in the Soviet Union, with an increase in the production of many
well heads being reported. Musk's specific plan would not be very feasible within the energy limitations of historically manufactured nuclear devices (ranging in kilotons of TNT-equivalent), therefore requiring major advancement for it to be considered. In part due to these problems, the physicist
Michio Kaku (who initially put forward the concept) instead suggests using
nuclear reactors in the typical land-based
district heating manner to make isolated
tropical biomes on the Martian surface.
Physics was first discovered, in minute quantities, following the analysis of the fallout from the first thermonuclear atmospheric test. The discovery and synthesis of new
chemical elements by
nuclear transmutation, and their production in the necessary quantities to allow study of their properties, was carried out in nuclear explosive device testing. For example, the discovery of the short-lived
einsteinium and
fermium, both created under the intense
neutron flux environment within thermonuclear explosions, followed the first
Teller–Ulam thermonuclear device test—
Ivy Mike. The rapid capture of so many neutrons required in the synthesis of
einsteinium would provide the needed direct experimental confirmation of the so-called
r-process, the multiple neutron absorptions needed to explain the cosmic
nucleosynthesis (production) of all chemical elements heavier than
nickel on the periodic table in
supernova explosions, before
beta decay, with the r-process explaining the existence of many stable elements in the universe. The worldwide presence of new isotopes from atmospheric testing beginning in the 1950s led to the 2008 development of a reliable way to detect art forgeries. Paintings created after that period may contain traces of
caesium-137 and
strontium-90, isotopes that did not exist in nature before 1945. (
Fission products were produced in the
natural nuclear fission reactor at
Oklo about 1.7 billion years ago, but these decayed away before the earliest known human painting.) Both
climatology and particularly
aerosol science, a subfield of
atmospheric science, were largely created to answer the question of how far and wide
fallout would travel. Similar to
radioactive tracers used in
hydrology and materials testing, fallout and the
neutron activation of nitrogen gas served as a radioactive tracer that was used to measure and then help model global circulations in the atmosphere by following the movements of fallout
aerosols. After the
Van Allen Belts surrounding Earth were discovered about in 1958,
James Van Allen suggested that a nuclear detonation would be one way of probing the magnetic phenomenon. Data obtained from the August 1958
Project Argus test shots, a
high-altitude nuclear explosion investigation, were vital to the early understanding of Earth's
magnetosphere. reference design for the
Project Orion spacecraft powered by
nuclear pulse propulsion Soviet nuclear physicist and
Nobel Peace Prize recipient
Andrei Sakharov also proposed the idea that
earthquakes could be mitigated and
particle accelerators could be made by utilizing nuclear explosions, with the latter created by connecting a nuclear explosive device with another of his inventions, the
explosively pumped flux compression generator, to accelerate
protons to collide with each other to probe their inner workings, an endeavor that is now done at much lower energy levels with non-explosive
superconducting magnets in
CERN. Sakharov suggested to replace the copper
coil in his MK generators by a big
superconductor solenoid to magnetically compress and focus
underground nuclear explosions into a
shaped charge effect. He theorized this could focus 1023 positively charged
protons per second on a 1 mm2 surface, then envisaged making two such beams collide in the form of a
supercollider. Underground nuclear explosive data from peaceful nuclear explosion test shots have been used to investigate the composition of Earth's
mantle, analogous to the
exploration geophysics practice of mineral
prospecting with chemical explosives in "
deep seismic sounding"
reflection seismology.
Project A119, proposed in the 1960s, which as Apollo scientist Gary Latham explained, would have been the detonating of a "smallish" nuclear device on the Moon in order to facilitate research into its geologic make-up. Analogous in concept to the comparatively low yield explosion created by the water
prospecting (LCROSS)
Lunar Crater Observation and Sensing Satellite mission, which launched in 2009 and released the "Centaur"
kinetic energy impactor, an impactor with a mass of 2,305 kg (5,081 lb), and an impact velocity of about , releasing the kinetic
energy equivalent of detonating approximately 2 tons of
TNT (8.86
GJ). design that was to provide
nuclear pulse propulsion to the
Project Orion vehicle
Propulsion use test shots are known as the "
rope trick effect". They are caused by the intense flash of X-rays released by the explosion heating the tower holding
guy-wires white hot.
Project Excalibur intended to focus these X-rays to allow attacks over long distances. The first preliminary examination of the effects of nuclear detonations upon various metal and non-metal materials, occurred in 1955 with
Operation Teapot, were a chain of approximately basketball sized spheres of material, were arrayed at fixed aerial distances, descending from the shot tower. In what was then a surprising experimental observation, all but the spheres directly within the shot tower survived, with the greatest
ablation noted on the aluminum sphere located from the detonation point, with slightly over of surface material absent upon recovery. The ablation data collected for various materials and the distances the spheres were propelled, serve as the bedrock for the nuclear pulse propulsion study,
Project Orion. In the 1970s
Edward Teller, in the United States, popularized the concept of using a nuclear detonation to power an explosively pumped
soft X-ray laser as a component of a
ballistic missile defense shield known as
Project Excalibur. This created dozens of highly focused X-ray beams that would cause the missile to break up due to
laser ablation. Laser ablation is one of the damage mechanisms of a
laser weapon, but it is also one of the researched methods behind pulsed
laser propulsion intended for spacecraft, though usually powered by means of conventionally pumped, laser arrays. For example, ground flight testing by
Leik Myrabo, using a non-nuclear, conventionally powered pulsed laser
test-bed, successfully lifted a
lightcraft 72 meters in altitude by a method similar to
ablative laser propulsion in 2000. that resulted in the
Cretaceous–Paleogene extinction event, which resulted in the extinction of the
non-avian dinosaurs some 65 million years ago. A natural impact with an explosive yield of . The most powerful man-made explosion, the
Tsar Bomba, by comparison had a yield almost 2 million times smaller – . The 1994
Comet Shoemaker–Levy 9 impacts on planet
Jupiter, the
Tunguska and
Chelyabinsk asteroid–Earth collisions of 1908 and 2013 respectively, have served as an impetus for the analysis of technologies that could prevent the destruction of human life by impact events. A powerful solar system based
soft X-ray, to
ultraviolet, laser system has been calculated to be capable of propelling an
interstellar spacecraft, by the
light sail principle, to 11% of the
speed of light. In 1972 it was also calculated that a 1 Terawatt, 1-km diameter
X-ray laser with 1
angstrom wavelength impinging on a 1-km diameter sail, could propel a spacecraft to
Alpha Centauri in 10 years.
Asteroid impact avoidance A proposed means of averting an
asteroid impacting with Earth, assuming short lead times between
detection and Earth impact, is to detonate one, or a series, of nuclear explosive devices,
on,
in, or in a
stand-off proximity orientation with the asteroid, with the latter method occurring far enough away from the incoming threat to prevent the potential fracturing of the
near-Earth object, but still close enough to generate a high thrust
laser ablation effect. A 2007
NASA analysis of impact avoidance strategies using various technologies stated: Nuclear
stand-off explosions are assessed to be 10–100 times more effective than the non-nuclear alternatives analyzed in this study. Other techniques involving the
surface or
subsurface use of nuclear explosives may be more efficient, but they run an increased risk of fracturing the target near-Earth object. They also carry higher development and operations risks. ==See also==