If all goes well, sometime in the next decade, an American lander will carry a small nuclear reactor to reach the moon base. Inside this reactor, a boron rod will stick into a pile of uranium to open the nuclear chain reaction. Split uranium atoms and release heat. Next, these heats will be transmitted to a generator, which will bring light to the lunar base.
NASA has gone through half a century of efforts to create a nuclear reactor that can be used in space, and has just completed a newly designed test. This new reactor is called Kilopower, and its next milestone may be in the 2020s. At some point in space, Kilopower was developed with the assistance of the U.S. Department of Energy. It marks the first new nuclear reactor built in the United States in 40 years. It may change space exploration, especially the permanent human outpost in the solar system. Energy manufacturing method.
Current space missions use fuel cells, nuclear batteries or solar energy. But the moon’s night lasts for two weeks, and the intensity of sunlight on Mars is only 40% of the Earth. Jim Reuter, Deputy Administrative Assistant, NASA Space Technology Division Says: 'When we go to the moon or eventually to Mars, we are likely to need a lot of energy that cannot rely on the sun, especially if we want to live there.'
Kilopower is a small, lightweight fission reactor capable of supplying up to 10 kilowatts of electricity. NASA says four 10-kilowatt Kilopower reactors will provide enough power for Mars or a human base on the moon. Experts in the field of research, Claudio Bruno, a professor of engineering at the University of Connecticut, said that 40 kilowatts of electricity can meet the needs of three to eight families in the United States.
He added: '40 kilowatts is roughly equivalent to 60 horsepower, and you may think that it is not enough. In fact, if you want to do anything useful, especially if the moon or Mars mission is a manned mission, you need to The energy will be more. But every time in the past, there are people who protest against the deadly danger of nuclear power. This is the first time in decades that people talk about using nuclear reactors to provide energy for generators, so this is the first positive signal.
In space exploration, there are two main ways of using nuclear energy: making electricity or generating propulsion. Kilopower will be used to generate electricity, just like the power station on Earth. It will generate more electricity than a single spacecraft. The need, which makes it more suitable for larger planet outposts. Kilopower will also be used to drive the spacecraft, mainly for the ion engine to provide energy, but NASA has not yet decided to use this technology.
Kilopower has been researching and developing since 2012, but its effect far exceeds that of NASA's auxiliary nuclear power system (SNAP) in the 1960s. The SNAP project has developed two nuclear power systems, one is radioisotope thermoelectric generation. (RTG), which captures energy from radioactive decay to provide thermal energy and electricity. Dozens of deep spacecraft have used RTG systems, including curiosity rover on Mars and a new vision of exploring dwarf planets in the outer solar system. Pluto detector.
Another power system of the SNAP project is the fission reactor system, which generates energy through atom splitting. This technology is the same as that used by nuclear submarines. NASA launched a nuclear power plant named SNAP-10A in April 1965. The nuclear power plant worked for 43 days and generated 500 watts of electricity before the failure. It is still in Earth orbit and it now becomes space debris.
In the 1960s and 1970s, NASA also conducted research on nuclear rocket propulsion technology in the rocket nuclear power application (NERVA) project. This technology uses a nuclear reactor to heat hydrogen gas and discharge gas through nozzles. Conventional rocket-fired fuel produces similar thrust. But this project ended in 1973.
According to the World Nuclear Commission data, Russia has launched more than 30 fission reactors into space. After the US President Richard Nixon canceled NASA’s nuclear power propulsion technology research in 1973, Russia also gave up its own project. Bruno said: 'All The study was halted in 1973. By 2018, most of the people who had participated in that project either retire or die. Although we still have reports, the report will not speak.
The study was thawed in 2012. NASA and the U.S. Department of Energy conducted a preliminary test of Kilopower's predecessor (DUFF experiment) and generated 24 watts of electricity. DUFF cooled the reactor with a heat pipe and showed it for the first time. The application of the Stirling engine to convert reactor heat into electrical energy. After the DUFF test, NASA authorized the start of the Kilopower project, which was the first time in 2014 that the project received funding for research.
The latest tests conducted by NASA and the Department of Energy on Kilopower began in November 2017 and continued until March this year. During the test, the Kilopower reactor was tested for 28 hours of full power, then turned off and cooled. Marc Gibson, chief engineer at the Kilopower project at NASA's Glenn Research Center, said that the reactor is operating at 800 degrees Celsius and generates more than 4 kilowatts of electricity.
NASA and the Department of Energy stated that the Kilopower reactor is safer than previous versions because of its different operating methods. With the boron-activated rods and tantalum reflectors, the fission chain reaction is controlled and can even be stopped. According to the head of the Kilopower project, the United States Patrick McClure of the Energy Department's Los Almos National Laboratory said: 'If a reactor or rocket explodes on the launch pad, the uranium 235 in the core will not emit radiation to people within a kilometer from the natural environment. This is just the most In bad terms, we don't think there is a chance that the reactor will fail in the event of a launch.
According to David Poston, chief reactor designer at Los Almos National Laboratory, a similar reactor can provide energy to the ion thruster to provide the spacecraft with flying power. According to Bruno, however, the amount of raw materials required to initiate the fission chain reaction It is very likely that the reactor will be large and heavy and it will not be practically applied. NASA proposed a completely new uranium nuclear heat engine concept, which is similar to the technology used in current chemical fuel rockets. However, 2017 will be 8 The nuclear thermal propulsion system project started this month has not made such progress as Kilopower.
Most nuclear-powered spacecraft use the RTG system to generate electricity by collecting the heat generated by decay. However, the energy efficiency of RTG is extremely low. In addition, the supply of cerium oxide raw materials is insufficient. After experiencing a gap of 30 years, the US Department of Energy The recovery of the 238 production began in 2015, but currently the inventory in the United States is only enough to provide energy for NASA's 2020 Mars rover, and it may be able to support one or two potential missions to the outer solar system.
Kilopower can be used as a substitute, but government officials and experts all think the possibility is great. Gibson said: 'From an energy perspective, we started with the RTG project. We hope this project will enable us to achieve more. The use of, say, deep space exploration, then you need thousands of watts of electricity to supply. In other words, humans need more than ten to hundred times more energy than a single Kilopower reactor to operate on the moon or on Mars. However, Poston said that the standardized design of the reactor can be easily scaled to meet those needs.
Bruno added that the Kilopower reactor is an important step in building a usable nuclear power plant in space. It is very likely that the reactor will be tested in space. NASA has not yet licensed such a project, but at a press conference earlier this month Previously, Reuters said that in the next 18 months will be committed to how to conduct such test flights. One possibility is to use a lunar spacecraft to transport a small Kilopower reactor, and this small reactor may be in NASA. The latest moon exploration mission was developed.
Poston said: "Successful ground testing is important for the future of human space exploration. We have verified that this technology concept is now available to NASA. For me, the most exciting thing for me is its potential applications. In the true sense, this is the first step we have taken in the research field of fission energy technology available in space.
