NASA successfully tested the components of compact nuclear reactors with a Stirling engine, developed under the Kilopower project, and intended for installation on space vehicles for long-range missions.
The agency assigned tests with full-scale launch of the reactor at full capacity at the end of March, reports Reuters.
Usually spacecraft use solar panels as an energy source. But in the case of missions to the solar planets far from the Sun, there may not be enough, therefore, thermoelectric generators are almost always used on such apparatuses. They convert the thermal energy released during the decay of radioactive isotopes into electric current. The power of such reactors is independent of the Sun, but it is usually small and amounts to about hundreds of watts, with most such generators working on expensive plutonium 238Pu, which encourages engineers to look for more powerful and cheaper solutions.
NASA is also working to build more efficient reactors within the Kilopower project. They will work on enriched uranium, and their capacity, depending on the modification, will be from one to ten kilowatts. An interesting feature of the project is the method of converting thermal energy into electrical energy. Usually thermoelectric or thermionic converters were used in such designs (including in Soviet projects), but NASA engineers decided to use the Stirling engine. In it, the heat expands the working body, which pushes the piston connected to the electric generator.
At the end of last year, NASA announced the multi-year funding of the project and the beginning of the initial tests. On January 18, the agency announced that experts from the Los Alamos National Laboratory conducted the first tests of the reactor components. The tests were successful, and the results coincided with the simulation. The representative of NASA also said that the tests with the launch at full capacity will begin in the middle or end of March.
There are also more unusual alternatives to solar panels as an energy source for space vehicles. For example, in Russia, a laser transmission system is being developed for this purpose. It is planned that the “tanker” will be launched into space, which will transfer energy to other devices.