Meet the radiation measuring mannequins on their way to the moon


Two mannequins made by researchers from DLR in Germany have been supplied to NASA in Florida, USA so they can be launched on board NASA’s Artemis I lunar mission later this year.

Artemis I will send a spacecraft capable of supporting a human crew to the Moon for the first time in almost 50 years. The test flight, which is plannd to launch this summer will be uncrewed, apart from the twin measuring mannequins Helga and Zohar on board the Orion capsule.

The two identical female mannequins are part of the MARE experiment developed by engineers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). They will measure radiation exposure during the six week flight – NASA plans to send the first woman to the Moon during the Artemis program this decade.

The Space Launch System (SLS) (Image: NASA)

Researchers at the  in Cologne developed the experiment and have now delivered it to NASA’s Kennedy Space Center (KSC) for installation.

As well as measuring radiation Helga and Zohar will test a new radiation protection vest as part of the experiment. The mannequins are made from materials that mimic the human bones, soft tissues and organs of an adult woman and have more than 10,000 passive sensors and 34 active radiation detectors inside them.

Mea­sur­ing man­nequin Helga (Image: DLR, CC BY-NC-ND 3.0)

Both phantoms are 95cm tall and weigh 36kg. Helga will fly unprotected to the Moon, while Zohar will wear the newly developed radiation protection vest, called the AstroRad, which has been developed by Israeli company Stemrad. By comparing the two sets of data, it will be possible to determine the extent to which the vest protects an astronaut from harmful radiation exposure.

Thomas Berger, head of the biophysics working group at the DLR Institute of Aerospace Medicine and head of the MARE project said, “MARE is the largest radiation experiment ever to be flown beyond low Earth orbit. We are looking to find out exactly how radiation levels affect female astronauts over the course of an entire flight to the Moon, and which protective measures might help to counteract this.

“Over the past few months at the DLR sites in Cologne and Bremen we have been studying Helga and Zohar thoroughly, including conducting tests to determine the effects of the vibrations that they will be subjected to during the launch of the Artemis I mission. The aim is to ensure that everything runs smoothly later at the Kennedy Space Center.”

Artemis I is now planned to launch in summer 2022. The assembly and installation of the measuring mannequins is scheduled to take place four weeks before the launch.

The female body is more sensitive to this radiation than the male body in organs such as the breasts and different radiation boundary values apply to female astronauts than to their male colleagues. However, so far there have been no sex-specific measurements using mannequins in space.

MARE man­nequins Hel­ga and Zo­har ready for transport (Image: DLR, CC BY-NC-ND 3.0)

Cosmic radiation in space

When astronauts leave Earth, they are exposed to the full spectrum of radiation found in space. The Orion spacecraft will experience two periods of intense radiation as it flies through the Van Allen Belt – once in the first few hours after launch and upon its return to Earth – which harbours charged particles trapped by Earth’s magnetic field.

Beyond the protection of Earth’s magnetic field, Orion will face a harsher radiation environment than the crew of the International Space Station (ISS), which is in low Earth orbit. Outside the Van Allen Belt, the space radiation environment includes energetic particles produced by the Sun in solar flares as well as galactic and extragalactic cosmic ray particles that originate from outside the Solar System.

Mock-up of Orion with mannequin crew on board during flight (Image: DLR, CC BY-NC-ND 3.0)

“Cosmic rays are a particular challenge for long missions in open space, because they deliver a continuous level of high-energy ionised particles,” said Christine Hellweg, head of the radiation biology department at the DLR Institute of Aerospace Medicine. “Particles in cosmic rays range from hydrogen to iron and uranium.”

Anthropomorphic phantoms 

Helga and Zohar are anthropomorphic phantoms – measuring bodies modelled on a human torso. DLR’s Institute of Aerospace Medicine has previously conducted experiments including a phantom called Matroshka, which was deployed on the ISS between 2004 and 2011.

Matroshka was mounted to the exterior of the ISS and gathered radiation readings representative of those experienced by an astronaut performing a spacewalk. The phantom was also placed in different parts of the Space Station to measure radiation exposure.

“Astronauts on the ISS are exposed to radiation levels that are approximately 250 times higher than that experienced by people on Earth. Radiation exposure during exploration missions further from Earth’s magnetic field or in interplanetary space could be much higher – in fact, our estimates predict up to 700 times higher,”said Berger.


This article has been edited from its original form on the DLR website.

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Ben has worked as a journalist and editor, covering technology, engineering and industry for the last 20 years. Initially writing about subjects from nuclear submarines to autonomous cars to future design and manufacturing technologies, he was editor of a leading UK-based engineering magazine before becoming editor of Aerospace Testing in 2017.

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