Physicist's invisible radiation shield may help NASA

Technology surged forward when the U.S. government invested heavily in science and engineering in the 1960s to get humans to the moon.

Now, 50 years after Neil Armstrong set foot on the lunar surface in July 1969, some of the work in UWM labs has the potential to make space exploration safer and transport space travelers even farther.

With private companies now contributing – and shouldering some of the astronomical costs – UWM research could attract the attention of a growing number of interested parties.

NASA officials say that landing people on the surface of Mars is an achievable goal. But a major barrier is the lack of an effective way to shield people from dangerous highenergy radiation, which bathes outer space beyond Earth.

Lead is one of the few physical materials that could deflect these deadly particles, but it’s too heavy to add to spacecraft.

But members of Prasenjit Guptasarma’s lab, together with NASA collaborators, have suggested an alternative. The Earth is shielded by a magnetic field encompassing the planet. Why, then, couldn’t a magnetic field be created to protect people in the space shuttle?

Guptasarma, a professor of physics, researches unconventional magnetism and superconductivity in materials. He conducts some of the work with a superconducting magnet – an electromagnet that is wrapped in superconductive wire.

Below a certain temperature, there is no electrical resistance in a superconducting wire; an electrical current can flow unrestricted, and a superconducting coil can conduct electric currents forever, without any outside electrical power source like a battery. So, a superconducting magnet can maintain a magnetic field forever.

Guptasarma’s lab has investigated the feasibility of generating a magnetic shield powered by a superconducting magnet. The current would be initiated on Earth and last the entire journey to Mars.

There are still lots of questions to answer before the idea could be designed, he said. Could deep-space radiation change the temperature at which superconductive properties appear? Could galactic radiation eventually destroy the magnetic shield itself?

To test it further, he will need a high-energy beam of particles that simulates the deep-space cosmic rays. Brookhaven National Laboratory in New York has the right equipment, and Guptasarma is looking for funding.

By Laura Otto, University Relations