Dummy Strapped Outside Space Station

Feb. 25, 2004 -- -- "Matroshka" is going where none of his kind has gone before — riding around on the outside of the International Space Station.

It will be a rough journey, but Matroshka is designed to take abuse — and measure it.

Matroshka is a mannequin of a human torso, fashioned from plastic, foam and real human skeleton, that was sent up at the end of January to the space station. Astronauts attached it to the exterior of one of the station's modules during their risky spacewalk today.

It will then remain exposed to the harsh environs of space for an entire year, in research guided by the European Space Agency, along with NASA.

Scientists hope the ordeal will pay off — in data. Matroshka's torso is equipped with dozens of radiation sensors that are placed in strategic locations throughout its surface and interior to measure how susceptible different organs and tissue may be to radiation damage.

The research is critical to understanding how to protect astronauts from radiation as they spend long durations in space on board the space station, or in a possible journey to the moon and Mars, as proposed recently by President Bush.

"The challenge is the radiation that astronauts are exposed to is of many different types and we really don't understand it yet," said Steve McKeever, a physicist at Oklahoma State University in Stillwater, and one of the scientists who contributed an instrument to Matroshka's array. "It's a real soup of radiation up there."

Radiation is energy in transit in the form of high-speed particles and electromagnetic waves. While minimal amounts of radiation reach people on Earth, it is much more prevalent and intense in space.

The pummeling particles originate as flares from our sun or from cosmic rays zooming in from distant solar systems. This means an astronaut taking a walk in space is exposed to about 27 times more radiation particles than the average person on Earth.