Dr Mitra Safavi Naeini (left) continues her commentary of the radiation studies being undertaken in the Artemis II mission.<\/p>\n
A 10-day lunar flyby will not settle late cancer risk, cardiovascular risk, central nervous system risk, reproductive risk, or the consequences of spending months in transit to Mars.\u00a0<\/p>\n
One reason is that some of the biggest uncertainties lie precisely in chronic, low-dose-rate exposure to mixed fields of heavy ions: the hardest thing to mimic perfectly on Earth and far too slow to resolve on a single short mission.<\/p>\n
It will not answer the\u00a0very different\u00a0problem of radiation exposure during repeated moonwalks on the lunar surface, where the Moon blocks\u00a0roughly half\u00a0the sky but also becomes part of the\u00a0radiation\u00a0source, as galactic cosmic rays striking the regolith\u00a0generate secondary or \u201calbedo\u201d neutrons.<\/p>\n
It will not produce a final \u2018safe dose\u2019 for exploration. What\u00a0Artemis II\u00a0can do is reduce uncertainty:\u00a0validate\u00a0models against measurements in a real deep-space\u00a0mission, show how well the monitoring hardware works with a crew aboard, and begin tying physical dosimetry to biological and operational data.\u00a0<\/p>\n
This is also why flight data and accelerator data solve opposite halves of the problem. Orion gives researchers the\u00a0real mixed field, the real low\u00a0dose rate in\u00a0the real spacecraft geometry.\u00a0<\/p>\n
Ground facilities such as NASA\u2019s Space Radiation Laboratory, ANSTO\u2019s Centre for Accelerator Science, Australian Centre for Neutron Scattering and the Australian Synchrotron\u00a0give them something flight never can: control.\u00a0<\/p>\n
They can isolate\u00a0radiation\u00a0species, energies,\u00a0materials\u00a0and electronics, and ask mechanistic questions one beam at a time.\u00a0\u00a0At the same time, this work\u00a0approximates deep space, not a perfect copy. Future protection strategies depend on both.\u00a0\u00a0<\/p>\n
Radiation matters just as much for hardware. Energetic particles can flip memory bits, trigger latch-up and other single-event effects, build up total ionising dose over time, and displace atoms in semiconductor lattices.\u00a0<\/p>\n
The same environment that threatens cells can corrupt a sensor, a\u00a0processor\u00a0or a power system.\u00a0Optics and solar materials darken or degrade.\u00a0Artemis II even carries a CubeSat, TACHELES, to measure effects of the space environment\u00a0on electrical components and systems.\u00a0<\/p>\n
A spacecraft that protects its crew for ten days will not automatically keep its avionics, solar\u00a0arrays\u00a0or surface hardware functioning for years.\u00a0<\/p>\n
Under NASA\u2019s updated architecture, Artemis III is now planned as an Earth-orbit systems demonstration, with Artemis IV targeted as the first Artemis lunar landing. The radiation data gathered now feed directly into what comes next: how landers\u00a0and habitats\u00a0are configured, where future crews shelter during solar events, how much margin surface systems need,\u00a0how electronics are qualified,\u00a0and which parts of the problem must still be solved on the ground using\u00a0irradiation facilities, materials testing and radiobiology.\u00a0<\/p>\n
Artemis is often described as a return to the Moon.\u00a0In reality, it\u00a0is a transition from short sorties to operations that must eventually become routine. Radiation is one of the hard constraints on that transition\u00a0because it\u00a0is not\u00a0a single hazard\u00a0but a moving target: physics, environment, material, geometry, biology\u00a0and operations are all tangled.<\/p>\n
The photographs from Artemis II will be remembered. But for the engineers, physicians,\u00a0biologists\u00a0and radiation scientists planning what comes after this flyby,\u00a0the data that matters most\u00a0will be\u00a0the\u00a0radiation\u00a0data map inside Orion, built particle by particle while four astronauts travel beyond Earth\u2019s magnetic shelter.\u00a0<\/p>\n
Meanwhile, those four astronauts will see\u00a0and document\u00a0the Orientale basin\u2014\u00a0the Grand Canyon of the Moon\u2014a 930-kilometre-wide impact scar (pictured above) formed when an object\u00a0roughly 60\u00a0kilometres across struck the surface 3.8 billion years ago. They will see the Ohm crater, with its bright rays of ejected material and the\u00a0Pierazzo\u00a0crater, streaked with rock that melted, flowed, and froze.\u00a0<\/p>\n
Before launch, they memorised fifteen lunar features to stay oriented. Crew member Koch has already described an uncanny sensation as the far side came into view. She said, \u201cThe darker parts just\u00a0aren\u2019t\u00a0quite in the right place. Something about\u00a0you\u00a0senses that is not the moon that\u00a0I\u2019m\u00a0used to seeing.\u201d\u00a0<\/p>\n
There is no dark side of the Moon, really.\u00a0As a matter of fact,\u00a0there never was. We just had to go around to\u00a0find the light.\u00a0\u00a0<\/p>\n