Status: 02/19/2022 09:53 a.m
How dangerous is space radiation for astronauts? Scientists want to find out using plastic dolls that they send into space.
50 years after the last Apollo flight, NASA plans to fly towards the moon again in April or May. The aim of the Artemis 1 mission is initially to orbit the moon with the unmanned Orion spacecraft. From the mid-2020s, astronauts will fly, land on the moon again and set up a lunar base there.
The program was named Artemis in reference to the Apollo program. Artemis is the moon goddess and twin sister of Apollo in Greek mythology. The Americans have set themselves the goal of putting the first woman on the moon.
Equipped with gauges
Although the Artemis-1 flight will be unmanned, three of the four seats on the Orion spacecraft will be occupied. In addition to a crash test dummy, two plastic dummies, so-called phantoms, sit in the capsule. They are equipped with radiation measuring devices. The scientists want to find out how much space radiation affects the body during a flight to the moon and what protective measures would have to be developed for future missions with astronauts.
Both space agencies and private companies are planning long-term human stays on the Moon and Mars in the coming decades. However, space radiation is a major health problem.
How high is the radiation exposure?
The project management for the phantom experiment entitled MARE (Matroshka AstroRad Radiation Experiment) lies with the German Aerospace Center (DLR) in Cologne. Radiation physicist Thomas Berger explains:
In principle, we want to clarify fundamental questions with this MARE experiment: What is the radiation exposure of humans in free space? We are currently limited to the International Space Station (ISS). We want to know: How high is the radiation exposure and is it increased compared to the space station? And does this increase the risk of cancer?
To find out, the researchers send two women’s bodies into space. The phantoms are named Helga and Zohar. “If you compare the cancer risk of men and women, it is higher for women, for example due to the higher incidence of breast cancer. Also, we now have more female astronauts who will fly, so it makes perfect sense to have two women go to the moon here send and return,” explains Berger.
Radiation detectors are inserted into the cut-open dolls.
Image: NASA/LM/DLR
Cut into 38 slices
The scientist sits at a large laboratory table. In front of him are the phantoms, each cut into 38 slices. The discs have different densities and thus simulate the various human organs.
Thomas Berger is in the process of inserting small crystals into a gray disc with tweezers and explains: “This is a head layer, so to speak the brain. We are currently equipping this layer of Helga with radiation detectors. They measure exactly on this during the space flight Point the radiation. By inserting these small crystals at a total of 1400 measuring points in the test bodies, we can measure something like a three-dimensional distribution of the radiation dose over the entire body after the space mission.”
The researchers want to find out how much space radiation reaches the most radiation-sensitive organs in the body, including the lungs and stomach.
In addition to these crystals, the so-called passive radiation detectors, the phantoms also get active radiation detectors. These battery-powered measuring devices were developed at DLR and record current data every five minutes during the mission. After the phantoms return from space, the researchers find out exactly where in space the phantoms were exposed to which radiation.
Different types of space radiation
Christine Hellweg, head of the Radiation Biology department at the DLR Institute of Aerospace Medicine, explains the types of radiation in space:
One radiation comes from our sun, these are the solar energetic particles. And the other comes from outside our solar system: the galactic and extragalactic cosmic rays. Our sun always blows the particles away, thereby partially protecting us from this galactic cosmic radiation. When the sun is very active, less comes into our solar system from the outside. But we always have some level of energetic particles, ionized particles, everything from hydrogen to iron to uranium in the galactic cosmic rays.
Radiation vest as protection
In order to test whether and how astronauts can protect themselves against space radiation, one of the two phantoms will wear a radiation protection vest developed in Israel during the flight.
Christine Hellweg explains: “The radiation vest is primarily something for the particle events from the sun when we have an eruption on the sun’s surface. Then the internal organs and especially the bone marrow could be better protected. The vest might also become a bit the Reduce dose from galactic cosmic rays, but it’s not really meant for astronauts to wear all the time.”
“There is no magic bullet yet”
Radiation could at least be reduced on the moon or Mars, where astronauts spend most of their time in well-protected habitats. At present, however, the researchers do not yet know how to reduce space radiation in spaceships to zero.
Cladding spaceships in a completely radiation-proof manner would not work simply because of the weight of the materials. For the months-long flights to Mars, for example, there is still no practicable solution, says Christine Hellweg: “One solution would be to fly faster. Or to find anti-radiation drugs. But there is simply no miracle cure.”