For Captain Kirk and his crew, the starship Enterprise’s force fields were all that stood in the way of oblivion from Klingon lasers. Now scientists are seeking to build Star Trek-style shields for real, to protect astronauts on their way to Mars.

Though a manned mission to the Red Planet could probably expect to avoid any unpleasant alien encounters, researchers believe that magnetic fields could be crucial to shelter its crew from deadly radiation.

Cosmic rays and solar flares are one of the chief hazards faced by astronauts venturing into space, and the need to protect crews against them is one of the biggest obstacles to long missions.

On the surface of the Earth, the magnetic field that envelops our planet deflects most of this radiation, and even in the low orbits used by the space shuttle and the International Space Station (ISS) it offers a measure of protection.

Beyond this magnetic field, however, astronauts would be exposed to constant low levels of radiation that would raise their risk of cancers. Solar flares — eruptions of charged gas or plasma from the Sun — pose an even greater danger, as they would kill anyone unshielded in their path.

Neil Armstrong and the other Apollo astronauts spent only ten days in space on their trips to the Moon in the 1960s and 1970s and were lucky in that no solar flare came their way while they were in space.

On the ISS, astronauts protect themselves against flares by moving into a special thick-walled room, but such barrier shielding would be impractical for a mission to Mars.

Now scientists at the Rutherford-Appleton Laboratory in Oxfordshire are proposing a Star Trek solution: to protect the spacecraft with a magnetic field like the Earth’s. A team led by Ruth Bamford, who will present details today at the Royal Astronomical Society’s annual meeting in Preston, has been awarded a £30,000 grant by the Science and Technology Facilities Council to start developing such a scheme. It will use technology originally developed for experimental nuclear fusion reactors to wrap a model spacecraft in a magnetic cocoon, so that harmful plasma bounces off.

“It’s no accident that Star Trek featured this sort of technology, as it had advisers who work for Nasa and it’s feasible,” Dr Bamford said. “The shields seem to be some sort of invisible barrier, which energy bounces off, and that sort of deflector shield is exactly what we’re talking about.”

Magnetic field generators, she said, could be critical to Nasa’s plans to establish a permanent manned base on the Moon by 2024, and to send astronauts to Mars around 2030.

“Now there’s the will to send astronauts back into space, we need to be able to do it safely. That means protecting astronauts from radiation.”

Artificially generated magnetic fields are already used in experimental fusion reactors to keep superheated plasma from touching its walls, which would otherwise melt. “What we want to do is the opposite,” Dr Bamford said. “In fusion, the aim is to keep the plasma in. We want to keep it out.”

The team is currently setting up an experiment at Manchester University, where it will use magnets to try to deflect a one-metre beam of plasma. “We have already tried with a little magnet, but while that deflects it a bit it doesn’t keep the plasma off,” Dr Bamford said.

“All the components that we need for this already exist. It is a matter of design and engineering to put them together.”

Science fact

— Ion engines Nasa’s Deep Space 1 comet chaser, and the European Space Agency’s Smart1 probe, have ion engines. Charged atoms are fired into space at about 1,000mph (1,600km/h), building up to propel the craft at up to 36,000mph

— Artificial eyes Scientists at the University of Southern California have created a “bionic eye” that has already been fitted to six blind patients

— Cloaking devices Scientists at Imperial College London have shown that it is theoretically possible to create materials that bend light so that they appear invisible

Source: Times database

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