Why does Mars Rover Perseverance run on nuclear power, and not wind or solar?
In the hearts of many Americans, there is nothing more futuristic than space exploration. It is interesting to note, then, that the Mars rover Perseverance runs on nuclear fuel, not wind or solar.
According to an article in Space.com:
“A spacecraft is only as strong as its power source, which is why when NASA was designing its Perseverance Mars rover, the agency turned to radioactive plutonium.
The plutonium that will be blasting off the planet on Thursday (July 30) isn’t in the same form as is used for weapons, and it’s well protected in case something happens to go wrong during the launch. But these plutonium units are a respected power source for spacecraft — NASA’s Curiosity rover runs on a similar device.
“NASA likes to explore, and we have to explore in some very distant locations, dusty locations, dark locations and harsh environments,” June Zakrajsek, a nuclear fuel expert at NASA’s Glenn Research Center in Ohio, said in a Department of Energy (DOE) podcast about the Perseverance mission. “When we’re in those kinds of environments, solar energy sometimes does not provide the power that we need. The light just does not get to those locations like we would need it.
Some NASA missions to Mars have run on solar energy, of course — the InSight lander currently operating on the Red Planet bears solar panels, as did the twin Spirit and Opportunity rovers earlier this century. But Opportunity is a mascot for the weaknesses of solar energy at Mars, since the rover’s end came when a massive global dust storm blocked it from tapping into the sun’s light. Run a rover on nuclear power and you don’t have to worry about that scenario.
So for the Perseverance rover, NASA turned to plutonium in a system called a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), which should be able to power the spacecraft for about 14 years.
“You don’t have extension cords, you can’t run out for a repairman,” Bob Wham, a nuclear fuel expert at Oak Ridge National Laboratory, said in the same podcast. “You have to be totally reliable.”
Nuclear power sources of other varieties have also traveled to deep space on missions like the forty-year-old twin Voyager probes and the Cassini spacecraft that dived through Saturn’s rings.
Perseverance’s MMRTG is designed to produce 110 watts of power, about the same as is used by a light bulb. The plutonium will decay, emitting heat that a generator converts into energy to power all of the rover’s instruments, plus producing enough heat to protect the spacecraft from the freezing nights and winters on Mars.”
Nuclear power is reliable and capable of providing the power that we need to explore infinity, and beyond. Rather than building our electric grid to run on unreliable wind and solar energy sources, we should take a page from NASA, the government agency that is probably the most associated with science, and look to nuclear power to deliver the energy we need, exactly when we need it.
Wind and solar are 18th-century technologies masquerading as the future.