Volume 43 | Number 1 | Fall 2012

ISU Photographic Services/Susan Duncan

Heading to the Red Planet

Fall 2012 Issue

The $2.5 billion Curiosity rover successfully landed on Mars on Aug. 6 and Idaho State University's Mike Smith is confident about his part in powering the automobile-size craft that travelled more than 339 million miles to the Red Planet.

"It's exciting and I am glad the Idaho Accelerator Center is doing work that is in this realm," said Smith, an engineering physicist with the ISU Idaho Accelerator Center.

Smith designed the portable linear accelerators that the Idaho National Laboratory used to check the welds on the Curiosity's nuclear power supply.

Portable linear accelerators developed at the IAC were also used to check the welds on the spacecraft New Horizons, which was launched in January 2006 and is expected to reach Pluto in July 2015.

On such costly, important and demanding missions it is important that the welds hold on the metal cases used to encase the plutonium-238 that is used to power the rover. Curiosity uses as its power source a Multi-Mission Radioisotope Thermoelectric Generator, which is a nuclear battery that uses the heat supplied by plutonium 238 to create electricity.

"I follow the missions pretty closely because there is a lot riding on it," Smith said. "It is exciting to watch and I like to see how it is going because the Idaho Accelerator Center has something invested in it."

The plutonium is encased in iridium, the most corrosion-resistant metal, to form what is called a fueled clad. The welds on this fueled clad must be strong enough to not allow radioactivity material to leak and to ensure the MMRG has fuel.

The IAC's portable accelerators speed up electrons that travel near the speed of light. Those electrons are converted to high-energy photons or X-rays and are fired into the fueled clad, giving X-ray images. Those X-ray images are used to confirm the integrity of the fueled clads.

The Curiosity is the sixth NASA spacecraft to land on Mars. It travelled through space for more than eight months to reach its destination. The 1-ton Curiosity rover is designed to investigate whether Mars is, or ever was, capable of hosting microbial life.