The US makes materials that the spacecraft used for 88 years does not run out

With a long half-life, Pu238 can provide an abundance of energy for spacecraft for nearly nine consecutive years.

According to Live Science, Pu238 is a radioactive element . In the process of decaying into Uranium-234 nucleus , it emits heat, which can be used as an energy source. A number of space exploration ships, including those of Voyager in the 1970s, used the energy source taken from the plutonium isotope oxide (isotopes are atoms of the same element but different in the number of neutrons. in the nucleus).

Plutonium-238 is an ideal energy source for space missions for many reasons, one of which is a 88-year half-life. The half-life is the time it takes for half the number of atoms of an element to decay into another nucleus. This means that the heat supplied by it will not decrease within 88 years.

In addition, Pu238 "is stable at high temperatures, can generate a lot of heat with only a small amount, emitted radiation is also low and easy to shield, does not affect the tools and equipment Important spacecraft, " Bob Wham, head of the project at the Nuclear and Isotope Research Area, Ridge Oak's Energy Laboratory (ORNL), said.

The process of making Pu238 in the laboratory.(Photo: Oak Ridge National Laboratory).

According to the World Nuclear Association, Pu239 with a 24-year half-life is the most common isotope produced from uranium in nuclear reactors, so it is difficult to obtain Pu238 from these reactors.

During the Cold War, the US created Pu238 from nuclear reactors at the Savannah River in South Carolina."These reactors were shut down in 1988, and since then the United States has not been able to recreate this element," Wham said.

After the US stopped producing Pu238 , Russia was the only country that provided this material for space exploration projects. However, the production of Russian Pu238 has also stopped. Two years ago, the US Space Agency (NASA) restarted the Pu238 production project, with a budget of US $ 15 million per year for the Department of Energy (DOE) Nuclear Energy Department.

In the new experiment, Wham and colleagues mixed nitrous oxide with aluminum and compressed the member. Later, they irradiated these tablets to create neptunium-238 . This element is not stable, will decay very quickly into Pu238. In this way, they created about 50 grams of Pu238, enough to study properties.

Because scientists use the Department of Energy's existing infrastructure, they need to adapt to the available conditions."The reactors at DOE's research area are smaller than the ones at the Savannah River, so we have to change the technology accordingly , " Wham said.

Next, the team will test the purity of the sample and find ways to expand production scale.

"Once you can automate and scale up this process, countries will be able to produce electrical systems using radioisotopes like what NASA is doing in space exploration projects. " , according to Wham.

NASA's next mission is to use radioactive isotope energy in a spacecraft project to Mars scheduled for July 2020, according to researchers. The spacecraft will be designed to look for signs of life on the Red Planet, collect soil samples for experiments on Earth and study human exploration technology.