At the April 13th meeting of the American Physical Society, students from Drake University in Iowa presented their MISSFIT (Magneto-Ionization Spacecraft Shield for Interplanetary Travel) design [livescience.com] that uses superconducting magnets to generate a magnetic shield protecting spacecraft against cosmic radiation while in transit.
The design incorporates both passive and active magnetic shielding similar to the Earth's ionosphere.
With help from a small NASA grant through the Iowa Space Grant Consortium, experiments are already underway on the passive shielding, which could protect astronauts from high-energy gamma-rays that a magnetic shield can’t stop. The hope, said Lorien MacEnulty, a junior at Drake and a member of the team, is to solve a key safety problem that's delayed an eventual NASA mission to Mars: long-term exposure to interplanetary radiation.
Right now, the students are experimenting with a number of radiation-blocking fabrics that might be light enough to mount on a spacecraft.
"We expose [the fabrics] to radiation," MacEnulty told Live Science. "Then we count how many particles make it through the layers of fabric."
The active shielding on the other hand assumes that any future spacecraft would be 'roughly cylindrical' with room at either end for a superconducting magnet ring powered by nuclear reactors.
Those magnets wouldn't divert gamma-rays. But they would cause charged alpha particles — another component of cosmic rays that could strike the spacecraft and emit X-rays — to move toward the ends of the spacecraft, which would be capped by two bubbles of material filled with a mixture of ionized gas that mimics Earth's ionosphere.
As the alpha particles zoom through this ionized gas, they would lose energy in a process similar to the one that produces auroras in the ionosphere near Earth's own North and South Poles.
Many questions remain unanswered in the design and the students are already showing their maturity as researchers by planning out what will require investigation and study over the next several years.