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Radiation in Space: Are Astronauts at Risk?

In space, astronauts can be exposed to high levels of radiation from the sun and from other sources outside the solar system. This exposure—often hundreds of times greater than what we experience inside the earth’s atmosphere—can pose serious health risks, especially on long-term space flights.

Scientists on the space station are exploring the potentially harmful effects of space radiation exposure, and developing new drugs to counteract these effects. They’re also testing materials to help engineers design radiation-safe spacecrafts for future exploration.

Francis Cucinatta

Francis Cucinatta

Find out what is being done to protect astronauts from space radiation! Watch our video interview with Francis Cucinatta, the Radiation Health
Officer for the astronauts at NASA Johnson Space Center.

Radiation and the Space Station

Listen as Exploratorium science writer Mary Miller talks with astronauts Jim Voss and Susan Helms about space radiation and how it affects life and work aboard the International Space Station.

HearISS Engineer Jim Voss (NASA Image)


EXPLORATORIUM: Jim, do you get space weather forecasts on the International Space Station, and does the solar activity effect whether you go on space walks or not?

JIM: In fact, once in a while, they do give us reports of increased solar activity, solar flares. And when they do that, we monitor with our radiation detection devices onboard, using a different rate. And yes, we would consider that, if we had a large solar storm happening, or if we were forecasting one, we would probably delay a space walk because of the increased radiation hazard.


HearISS Engineer Susan Helms (NASA Image)

EXPLORATORIUM: Susan, is there anything that you do on the space station to protect yourself during a solar storm, during periods when there’s more activity from the sun?

SUSAN: Well, I don’t do anything in particular, but I have, I guess, something that has been done generically. We do have some extra radiation protection that has been launched as part of an early program to shield the crew members better. And I have taken a lot of this radiation protection, which looks like a bunch of white bricks, and I’ve used it to build my sleep station. So I don’t do anything during the working day to shield myself, but at night, every single night when I go to bed, my sleeping bag is contained within these radiation protection bricks. And by that, I’m getting some protection just every single time I go to sleep.


HearHear the astronauts talk more about life on the ISS

The Phantom Torso

  A Creepy Guest on the Space Station

Phantom Torso Fred
Researchers have affectionately named the Phantom Torso "Fred." (NASA Image)

Scientists have placed a specially designed artificial torso on the space station to study how radiation affects different parts of the human body in space.

The bones and organs of this "Phantom Torso," constructed to mimic human body parts, contain hundreds of sensors that measure radiation levels. There are about 1,600 detectors positioned throughout the torso that reveal how deeply radiation penetrates into the body. Embedded in critical organs like the heart and brain are other devices that collect radiation data at regular time intervals.

Data from the Phantom Torso will help researchers predict radiation exposure to astronauts on future space missions. Scientists can also compare torso data with radiation measurements outside the space station to learn how radiation-safe the facility is.


X-ray image of the Phantom Torso showing two radiation detectors. (NASA Image)


Exploratorium staff recently measured radiation levels in the museum using an instrument known as a dosimeter—the same tool used to measure radiation on the space station. Comparing the museum’s data with the station’s data reveals that radiation levels in space are significantly higher than levels on earth.


Find out how scientists measure radiation with the Phantom Torso! Watch our video interview with Gautam Badhwar, the Chief Scientist for space radiation at NASA Johnson Space Center.

Gudham Badwir

Gautam Badhwar

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