Scientists are hoping to have a better idea of how cosmic radiation affects astronauts’ health outside of the Earth’s protective magnetosphere — using data gathered by “human phantoms,” returning to earth on the Orion spacecraft as part of the Artemis I mission, under the Matroskha AstroRad Radiation Experiment (MARE).
“MARE is a continuation of a series of experiments carried out on the International Space Station between 2004 and 2009 as part of the Matroskha project, in which we also participated,” explains Pawel Bilski, professor at the Institute of Nuclear Physics PAN (IFJ PAN). “Back then, radiation dose data were necessarily collected in low Earth orbit. Now, thanks to the NASA Artemis I mission, human phantoms stuffed full of radiation detectors have for the first time gone beyond the protective range of not only the Earth’s atmosphere, but also the magnetosphere.”
A pair of “human phantoms” are due to splash down next week aboard Orion, having traveled beyond the moon. (📷: DLR)
The International Space Station orbits within the magnetosphere, but Artemis I sent the Orion spacecraft beyond in the first of a series of missions designed to prepare for a human return to the moon and new exploration of Mars. The craft launched in November this year, and is due to splashdown on 11 December — hitting the Earth’s atmosphere at Mach 32, or 24,500 miles per hour, in a fiery finale to its 1.3 million mile journey.
When it lands, it will bring with it Zohar and Helga — so-called “human phantoms” designed to monitor solar radiation and its likely effects on the astronauts taking part in future crowed missions to the same regions. One phantom, Helga, will be unprotected; Zohar, meanwhile, wears StemRad’s AstroRad vest — designed to protect against radiation exposure. Each has passive lithium fluoride radiation detectors installed roughly every 1.2″ through their bodies along with active silicon detectors in the locations of key organs — a total of more than 10,000 passive and 34 active detectors across both phantoms.
Helga, bottom, traveled unprotected; Zohar, top, is testing a radiation-proof jacket from StemRad. (📷: Frank Michaux/NASA)
“Our lithium fluoride detectors work in such a way that the amount of light emitted when they are heated is proportional to the dose deposited by cosmic ray particles that have interacted with the material,” Bilski explains. “The reading of the data is therefore reliable and relatively simple, albeit non-trivial. This is because different traps in the material have different properties and empty at different temperatures.”
Should Orion return safely, the phantoms will be sent to IFJ PAN for analysis — with results due to be presented “in the first months of next year,” the organization promises. Interested parties can learn more about the Artemis-I mission, along with live video from the Orion spacecraft, on the NASA website.