Atomic space

How humanity can harness nuclear technologies in the exploration of the Universe

The U.S. Secretary of Transportation and acting head of NASA, Sean Duffy, has confirmed that Americans have plans to deploy a small 100-kilowatt nuclear reactor on the Moon by 2030. It will not only provide energy for a permanent U.S. lunar base, but will also lay claim to a section of the Earth’s satellite’s surface for Washington, thus allowing the United States to get ahead in the lunar race with Russia and China. Sean Duffy’s announcement has not only spurred interest in humanity’s lunar programmes, but has also raised the question of new uses for atomic energy.

Interplanetary space

In general terms, there are two main directions for the use of atomic energy in space: the installation of nuclear reactors as sources of clean and virtually inexhaustible energy for permanent bases on the surface of celestial bodies or in orbit, and the use of nuclear power units for spacecraft. 

One of the fundamental questions facing any country that decides to build a base beyond Earth is the question of energy. While short landings like those carried out by American astronauts on the Moon do not require significant energy consumption and, as a result, stable and productive sources of this energy, the creation of a permanent base is impossible without constant energy replenishment. 
Specialists have questions about the validity of choosing a nuclear reactor as the main source of energy for a lunar base. Thus, any nuclear power plant needs heat dissipation — on Earth it goes into the atmosphere, but since there is no atmosphere on the Moon, it is necessary to additionally erect cooling radiators. However, in turn, large and heavy radiators can heat up during long lunar days, and ensuring their stability is also not the easiest engineering task: in the circumpolar zones, it is problematic to bury the radiators due to permafrost, while installation on some kind of supports is technologically very complex.

Area of control

At the aforementioned press conference where the head of NASA shared their plans, there was an interesting remark about how people involved in space programmes wanted to be the first to reach the most promising areas on the Moon and ‘claim that for America’.
Since a nuclear power plant — despite being one of the safest sources of energy — nevertheless remains a potentially hazardous facility, the USA could establish an area of control, restricting the entry of foreign astronauts under the pretext of ensuring the normal operation of the reactor. That is, without formally violating the Outer Space Treaty by declaring part of the Moon its territory, the USA would become the owner of the location where their nuclear power plant will be situated.
It is not only the United States that is concerned with finding a source of energy for future bases on the Moon. The heart of the Russian–Chinese project, the International Lunar Research Station (ILRS), which is planned to be built between 2031 and 2035, will be a Russian nuclear microreactor with a capacity of about 500 kilowatts, which will be delivered to the deployment site on Chinese spacecraft.
Belarus will also be involved in the exploration of the Moon alongside the Russians and Chinese within the framework of the ILRS project. Our country joined it on October 23rd, 2023, following the signing of a joint declaration on co-operation on the International Lunar Research Station between Belarus’ National Academy of Sciences and the China National Space Administration (CNSA).

Road to the stars

A second promising area for the development of atomic technologies in space is the use of nuclear reactors as power plants or as the main component of nuclear rocket engines.

The first nuclear reactor installed on board a spacecraft was Boeing’s SNAP 10A, which was part of the equipment on the Snapshot spacecraft launched on April 3rd, 1965. The 40-kilowatt unit operated successfully for 43 days until the decision was made to test an experimental ion engine. The device started up, but numerous electromagnetic pulses disrupted the operation of the onboard computers that reset the reflectors of the reactor, which quickly shut down afterwards.
Soviet research in this area, which had been conducted since 1955, was much more successful. This resulted in a whole range of nuclear power units, some of which went into serial production and were successfully used on artificial satellites. These included Romashka, Buk, installed on 31 reconnaissance and targeting satellites, Topaz and Yenisei.

NRE away from success

Another type of nuclear rocket engine (NRE) was proposed by the renowned physicist, Freeman Dyson, and was called the explosive type. Dyson believed that a spaceship could be accelerated by detonating megatonne nuclear warheads behind its stern, reinforced with a massive steel plate with copper cladding. According to his calculations, reaching Alpha Centauri — our nearest star — would require 300,000 charges and approximately 133 years of flight. The cost of the 400,000-tonne Orion spacecraft was estimated at a sum equivalent to approximately $840bn today.
It has been proven on prototypes that a thermal nuclear rocket engine is far more efficient than the chemical engines that are now widely used: during experiments on the American NERVA project, the jet exhaust velocity from the nozzle reached 6.9km per second, whereas a chemical engine could only achieve a maximum of 4.5km per second.
The second advantage of spacecraft with NREs is their high speed. According to NASA specialists, such a spacecraft is capable of reaching the Red Planet 20–25 percent faster than existing vehicles.
The use of nuclear technologies for space exploration is one way to achieve humanity’s expansion into the Solar System and, in the future, go beyond. Reliable, powerful and environmentally sound nuclear power plants will allow the creation of bases first on the Moon, and then progress to Mars and beyond, while spacecraft with nuclear power units will facilitate the further exploration of deep space and, possibly, the full transformation of humanity into an interstellar species.

Working prototypes take flight

Today, all leading space powers have returned to projects for spacecraft carrying an atomic heart. Russia has been working on the Zeus space tug, which is based on a nuclear electric scheme, for more than a decade. Roscosmos specialists promise to present a working prototype by the end of the current decade. American designers from Lockheed Martin are also full of optimism, working on the DRACO project, as part of which they are going to demonstrate a spacecraft with a thermal nuclear engine as early as 2027. Finally, engineers from the Celestial Empire have assembled a prototype engine with a lithium reactor, which can be used for flights to Mars.

BY THE WAY

In April of this year, the press service of the Moscow State University of Civil Engineering, which prepared the concept design for a lunar nuclear power plant, stated that the first station would cost ₽1.95 trillion. It can be placed in the circumpolar crater, Peary. Construction will be carried out by robots, using solar panels and radioactive elements to generate energy. Around the station, which will be a complex of 10-kilowatt power plants of the Romashka type, invented back in the USSR, a protective structure will be erected from lunar soil and kevlar. The service life is expected to be within ten years.

By Anton Popov