Life-sized mannequin will measure an astronaut?s cosmic-ray dose.
Researchers have long been aware that radiation in space is a problem, thanks to energetic particles called cosmic rays that are left over from the Big Bang. Earth's magnetic field stops us from being bombarded by these rays, but astronauts in space have little to protect them.
Those who spend long periods in space may risk health problems such as cancer through exposure to this radiation. During a spacewalk, an astronaut is hit by about 27 times as many cosmic particles than a person on Earth.
Much work has been done to assess the risk faced by astronauts in space. But little is known about the specifics of how much radiation reaches each organ in the body. Finding out could help with the design of better protective clothing, or in assessing the health effects of prolonged exposure.
So the European Space Agency and the Russian Academy of Sciences have designed Matroshka, an 80-kilogram dummy made of natural bone and plastics of various densities that serve as fake organs.
The doll is coated with a carbon-fibre covering that blocks ultraviolet radiation and deflects space debris, much as a space suit protects a live astronaut. And it has strategically placed radiation sensors to measure cosmic-ray doses to the stomach, lungs, kidneys, colon and eyes. It's because of all these layers that the mannequin is named after the famous hollow Russian dolls that open up to reveal ever-smaller versions of themselves inside.
Matroshka, which arrived safely at the space station last week, is expected to spend a year strapped to the outside of the station's Russian Zvezda module starting on 15 March. During that time, Matroshka will receive three times more radiation than a professional radiation worker's annual dose.
Out in the cold
With the advent of semi-permanent space-station crews, astronauts' long-term health is a pressing concern. "Flights in space are turning from heroic acts into routine work," says Vyacheslav Shurshakov of the Russian Academy of Sciences' Institute of Medical and Biological Problems in Moscow, one of the mission's organizers.
“Flights in space are turning from heroic acts into routine work Vyacheslav Shurshakov , Russian Academy of Sciences”
After its stint out in the cold, Matroshka will move indoors to take measurements inside the space station. With politicians' growing enthusiasm for a potential manned trip to Mars, data on on-board radiation doses will be valuable.
Most spacecraft are made of aluminium, through which cosmic rays can easily pass. A round-trip to Mars would take more than two years - far longer than the record 679 days spent on Russia's Mir space station by cosmonaut Valery Polyakov in 1994-95.
Matroshka's odyssey in space will be a valuable exercise. But it may be just the beginning of the measurements needed before we can confidently send men safely to Mars. The US National Research Council has previously predicted that it would take NASA 20 years to compile the necessary data to ensure that planet-hopping is safe.
Russian Academy of Sciences