Here's a way to miniaturize nuclear batteries for deep space

Here’s a way to miniaturize nuclear batteries for deep space

Color image of Pluto from NASA’s New Horizons spacecraft, taken in July 2015. Deeper exploration of the outer Solar System will require efficient spacecraft power systems. Credit: NASA / Johns Hopkins University Applied Physics Laboratory (JHUAPL) / Southwest Research Institute (SwRI)

As science and technology advance, we ask our space missions to deliver more and more results. NASA’s MSL Curiosity and Perseverance rovers illustrate this fact. Perseverance is an exceptionally refined set of technologies. These state-of-the-art rovers need a lot of power to perform their tasks, and that means bulky and expensive power supplies.


Space exploration is an increasingly energy-hungry endeavor. Orbiters and flyby missions can accomplish their tasks using solar energy, at least at the distance of Jupiter. And ion drives can take spacecraft to more distant regions. But to truly understand distant worlds such as the moons of Jupiter and Saturn, or even more distant Pluto, we will eventually need to land a rover and/or land on them as we did on Mars.

These missions require more power to operate, and that usually means MMRTGs (Multi-Mission Radioisotope Thermoelectric Generators). But they are bulky, heavy and expensive, three undesirable traits for spacecraft. Each cost over $100 million. Is there a better solution?

Stephen Polly thinks there is.

Polly is a researcher at the NanoPower Research Labs at the Rochester Institute of Technology. His work focuses on something most of us have probably never heard of: the development, growth, characterization, and integration of III-V materials by metalorganic vapor phase epitaxy (MOVPE).

This video provides a clear explanation of MOVPE. Credit: Chemical Vapor Deposition: Core Function – Nanotechnology: A Manufacturer’s Course

While this sounds complicated to non-specialists, space enthusiasts can easily relate to the idea that all his work has led to: a potentially new way to power space missions.

Polly is working on what could be a revolutionary way to power spacecraft on long journeys to the outer planets. It is called a thermoradiative cell (TRC) and is similar to an MMRTG. It uses a radioisotope as an energy source.

Polly is based on a technology called metalorganic vapor phase epitaxy (MOVPE). It uses chemical vapors to produce polycrystalline thin films. It’s an industrial process used in optoelectronics to make things like light-emitting diodes (LEDs). Polly’s work uses MOVPE to create thermoradiative cells (TRCs).

TRCs use a radioisotope just like MMRTGs and rely on heat from radioactive decay, but there is a difference. The decay heats the TRC, which then emits light. The light then reaches a photovoltaic cell, which in turn produces electricity. It’s kind of like a combination of an MMRTG and solar power.

But Polly’s idea is much smaller, and this is the holy grail of spacecraft engineering. “This device, driven by a radioisotope heat source, will allow an order of magnitude increase in mass-specific power (~30 vs. ~3 W/kg) and a three-order-of-magnitude decrease in volume (~0.2 vs. ~212). L) compared to a conventional multi-mission radioisotope thermal generator (MMRTG),” Polly explained in a brief press release.

Exploring the outer solar system requires energy – here's a way to miniaturize nuclear batteries for deep space

Polly’s thermoradiative cell concept could change the way we approach space exploration, allowing us to use smaller, more versatile spacecraft like CubeSats. Credit: Stephen Polly

Polly writes that these devices could help revolutionize our space exploration activities. It could lead to a proliferation of smaller spacecraft that don’t need to deploy large solar arrays or carry bulky and heavy MMRTGs. Advances in technology are continually shrinking scientific payloads, so if the power source can shrink along with them, CubeSats could become much more useful.

“This will directly enable small-scale missions to the outer planets, as well as operations in permanent shadows such as polar lunar craters,” explains Polly. The first use of the technology could be on a mission to Uranus. “We will look at a thermoradiative converter to power a CubeSat (or a fleet of CubeSats) that can travel with a flagship Uranus mission, performing such tasks as relaying information to atmospheric probes and obtaining a parallax view of the planet and months. ”

We’re along for the ride—or at least our intellect and imagination are—when we send spacecraft into the solar system to explore nature. If Polly’s work comes to fruition, and spaceships can be built with smaller and more efficient power sources, the journey will become even more exciting.

Polly’s idea is a first selection in NIAC, NASA’s Advanced Innovative Concepts program. He received funding to develop the idea further.

Provided by Universe Today

Citation: Exploring the Outer Solar System Needs Power: Here’s a Way to Miniaturize Nuclear Batteries for Deep Space (2023, January 20) Retrieved January 20, 2023, from https://phys.org/news/2023-01-exploring-outer- solar-power-miniaturize.html

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