January 14, 2013
Credit: Photo Credit: NASA/NIAC
Frank Morring, Jr. Washington
Astronauts on deep-space missions may one day deploy protective magnetic fields similar to those that shelter us from deadly space radiation on Earth, just as they will carry the necessary food and atmosphere.
NASA and its industrial and academic partners are studying ways to use superconducting magnets to generate magnetic fields around deep-space habitats. A promising approach would use coils that “inflate” with their own magnetism to deflect solar-flare protons and galactic cosmic rays that otherwise would restrict human travel time in space.
“The concept of shielding astronauts with magnetic fields has been studied for over 40 years, and it remains an intractable engineering problem,” says Shayne Westover of Johnson Space Center (JSC). “Superconducting magnet technology has made great strides in the past decade.”
Westover is principal investigator on a NASA Innovative Advanced Concepts (NIAC) grant to study high-temperature superconductor technology as an approach to active radiation shielding for astronauts. Under the grant, JSC is working with a company that has expertise in superconducting magnets to gain some definition on just how effective they can be in protecting spaceflight crews.
“Radiation shielding, if it is not at the top of the list, is No. 2,” says Palm Bay, Fla.-based Advanced Magnet Lab President Mark Senti. “They have propulsion figured out, and I'm not trivializing anything. They have solar protection and energy, but if you don't solve radiation shielding, there's no sense in doing engineering everywhere else.”
That was essentially the conclusion of the panel headed by former Lockheed Martin CEO Norman Augustine that studied the future of human spaceflight, at the beginning of President Barack Obama's first term. Since then, NASA has increased its focus on “enabling technology” for deep-space human exploration. The two-year, $500,000 NIAC grant headed by Westover is examining an AML concept that would launch superconducting-magnet coils and then expand them to provide the diameter necessary to produce enough magnetic shielding to protect a crew.
AML Chief Scientist Rainer Meinke conceived of attaching superconducting magnetic tape to a flexible material such as Kevlar. The perpendicular expansion provided by the Lorentz force when current is passed through the tape opens it from a collapsed configuration maintained during launch into large coils that can encircle a habitat. The current concept would launch six collapsed coils and the habitat separately, and then set up the active shielding in space (see illustration).