NASA’s Perseverance rover is the first spacecraft in years to use plutonium for fuel. The energy supply based on radioactive material drives the spacecraft’s operations on Mars and is designed to allow exploration of planets farther away in the Solar System. This is because the material presents itself as a more viable alternative than using solar energy to power a probe.
As a spacecraft moves farther away from the Sun in space, it needs nuclear technology to maintain its activities. In this way, the space agency reformulated a partnership with the US Department of Energy to produce and supply the fuel, which should be used in future missions. Before Perseverance, the Voyager, Cassini and New Horizons spacecraft already used plutonium as fuel.
“Our journey to achieve discoveries requires us to be able to let go of our own Solar System. Our energy supply doesn’t have to depend on our own star. the further we go [no espaço profundo], the more true it becomes”, commented Abigail Rymer, scientist at the Johns Hopkins University Applied Physics laboratory, in an interview to the website Space.com.
The construction of Perseverance created a compartment to transport the plutoniumSource: NASA/Reproduction
The system, called a dynamic radioisotope thermoelectric generator, is an improved and more efficient version of the models used in these vehicles. It also has the advantage of being able to act in more severe environments, such as places with low temperatures and high radiation.
“This allows you to explore places where sunlight doesn’t reach, but it also allows you to explore hostile environments. Reliability and other kinds of factors are really important to our missions — we couldn’t do some of them [sem levar isso em conta],” said June Zakrajsek, manager of the space agency’s Radioisotope Power Systems program.
NASA Partnership with the Department of Energy
The next NASA mission that will use nuclear fuel to power the spacecraft will be Dragonfly. It is scheduled to launch in 2027 and will aim to explore Titan, Saturn’s moon that receives about 1% of sunlight compared to Earth, which justifies the need for plutonium. Remember that Dragonfly is part of the New Frontiers program, alongside New Horizons, Juno and OSIRIS-REx.
The initiative aims to explore the Solar System through investigations in strategic locations, which can provide great advances for planetary science. Zakrajsek assessed the availability of fuel for these projects as “a big deal”.
The fuel will allow the exploration of more distant planets in the Solar SystemSource: NASA/Reproduction
For her, the new phase of the program is aligned with NASA’s annual planning for the preparation of upcoming missions, ensuring they will have the necessary supplies for their successes. Thus, there are efforts by the US Department of Energy to provide the plutonium to be applied in the construction of space vehicles.
Tracey Bishop, a member of the Department of Energy’s nuclear infrastructure program, revealed that the initiative comes from the space agency, which communicates to the public agency its interest in developing a new mission based on nuclear fuel. “Once the mission was over, we would slow down production and put it on hold until the next project,” he said.
That’s because the entire stable manufacturing system around a specific material — in this case plutonium oxide, also called plutonium-238 — is made exclusively for NASA use. In other areas, such as weapons and nuclear reactors, a type of plutonium is used with an extra neutron.
With plutonium, NASA hopes to reduce by two years the schedule related to the development of the necessary supply for the launching and permanence of the missions’ performance, a process that previously could take up to 10 years.