Dr. Marcelo Vazquez, Radiobiology Section Head at Canadian Nuclear Laboratories (CNL) supports the Artemis II mission at the intersection of nuclear science, biology, and medicine from his lab at CNL.
Humanity is heading back to the moon, but this time, the goal isn’t just to land — it’s to endure. As Artemis II ventures beyond the safety of Earth’s orbit, focus has shifted from the mechanics of the journey to the science of survival. Through persistent leadership in nuclear and health research, Canada is providing the quiet, essential science that will make long-duration missions possible.
Artemis II will be the first crewed flight of NASA’s Artemis program, paving the way for future long-duration missions, including the much-anticipated journey to Mars. Unlike the Apollo era, today’s exploration goals extend beyond brief visits. Space agencies have their eye on months-long lunar stays and, eventually, multi-year missions to deep space – but with that ambition comes new risks.
Beyond Earth’s atmosphere and magnetic field, we know astronauts are exposed to extreme temperatures and microgravity; what many don’t know is that they are also vulnerable to deep-space radiation.
“Radiation is one of the biggest barriers to long-term human deep space exploration,” says Dr. Marcelo Vazquez, Radiobiology Section Head at Canadian Nuclear Laboratories (CNL). “Once you leave Earth’s orbit, you lose the protection that makes life here possible.”
On Earth, the atmosphere and magnetosphere shield humans from most cosmic radiation. Even astronauts aboard the International Space Station benefit from that protection. Artemis II will venture far beyond it.
Earth’s atmosphere and magnetosphere act like a protective bubble, absorbing and deflecting radiation from the Sun and deep space before it can reach the surface. Once astronauts leave this shield, they’re exposed to much higher levels of radiation.
In deep space, astronauts face radiation from solar particle events, bursts from the Sun, and galactic cosmic rays originating beyond the solar system. These particles can pass through spacecraft shielding and human tissue, damaging DNA and increasing long-term health risks, including cancer and neurological effects.
The longer the mission, the greater the exposure. For future missions to Mars, where astronauts could spend years in deep space, radiation becomes a serious mission-limiting factor.
Understanding how the human body responds, and how to measure that response accurately, is now a central focus of international space research.
Dr. Vazquez and colleagues in his lab at Canadian Nuclear Laboratories’ (CNL) Chalk River site.
At the intersection of nuclear science, biology, and medicine, Dr. Vazquez works to translate complex radiation research into practical tools for astronaut protection. His role connects CNL’s expertise with Health Canada, the Canadian Space Agency (CSA), NASA, and international partners. This adds to the decades of research and science innovations made possible by researchers like Dr. Vazquez who have been advancing radiobiology, and health effects on health in terrestrial and non-terrestrial ecosystems during environmental, occupational and medical exposure.
“This research only works if physicists, biologists, physicians, and engineers are working together,” Dr. Vazquez says. “No single discipline can solve the problem on its own.”
That collaboration is especially important when the goal is not just academic knowledge, but real-world decision-making. For example, how much radiation exposure is acceptable, when countermeasures are needed, and how to respond if something goes wrong.
One of Canada’s key contributions to the Artemis II mission happens after the astronauts return to Earth.
Research from Health Canada led by Dr. Ruth Wilkins involves conducting cytogenetic studies using blood samples taken from Artemis II astronauts before and after their mission. By examining changes in chromosomes, scientists can identify radiation-induced DNA damage and estimate the dose absorbed by the body — a process known as biodosimetry.
Biodosimetry research helps mission planners understand cumulative risk, improve radiation shielding strategies, and prepare emergency response protocols if astronauts experience unexpected exposure. For future missions to Mars — where evacuation is impossible this knowledge is essential.
Cytogenetic studies analyze chromosomal changes to identify DNA damage, providing a form of biodosimetry that estimates the actual radiation dose absorbed by an astronaut’s body.
CNL anticipates the opportunity to support this work by helping refine calibration methods using particle accelerators in future projects. On Earth, biodosimetry is typically calibrated using conventional radiation sources like X-rays or gamma rays. Unlike the controlled radiation used in medical imaging or cancer treatment, space radiation is fundamentally different — a constant bombardment of high-energy protons, heavy ions, and secondary particles such as neutrons that can pass through a spacecraft and human tissue.
“Our job is to help bridge that gap,” Dr. Vazquez explains. “We work to understand the molecular and cellular changes induced by space radiation using different biological models, among them, human brain organoids.”
Dr. Vazquez at the Haughton-Mars Project in Devon, Nunavut.
Additional Canadian research, including work with the University of Ottawa, examines biological markers of oxidative stress — another way to understand how radiation affects human health at the cellular level.
The data gathered from Artemis II will not answer every question, but it will inform how future missions are designed.
“Artemis II is not the destination,” Vazquez says. “It’s a critical data point on the path to longer, and more uncertain missions.”
Canada’s involvement in Artemis II extends well beyond a single experiment. One of the four astronauts on the mission, Jeremy Hansen, is the first Canadian to travel to the moon. Canada is also contributing robotics, health monitoring research, and neutron detection technology for NASA’s planned lunar Gateway space station.
CNL, as Canada’s premier nuclear science organization, brings decades of expertise in radiation measurement, emergency response, and health protection. That experience has made Canadian data and methods a trusted staple among international partners.
“Canada has been part of space exploration since the beginning,” Dr. Vazquez notes. “The trust comes from consistency — showing up, delivering high-quality science, and collaborating openly.”
Dr. Vazquez showcases his organoid research contributing to the broader low-dose research programming.
Space radiation research does not stop at the edge of the atmosphere. Understanding how the body responds to chronic, low-dose radiation has implications for people on Earth too, such as those in communities exposed to higher natural background radiation and patients receiving radiation therapy for cancer.
“The same particles we study for space missions are used in advanced cancer treatments,” Dr. Vazquez says. “What we learn about protecting healthy tissue in space can directly improve outcomes for patients.”
As we near the launch of Artemis II, the mission represents more than a return to the moon. It marks a transition, from exploration driven by engineering alone to exploration grounded in human adaptation and survival. And in that effort, Canada’s contribution is not just historical, it’s foundational to what comes next.
This research is funded by Atomic Energy of Canada Limited’s (AECL) Federal Nuclear Science & Technology (FNST) Work Plan, which connects federal organizations, departments, and agencies to the nuclear science expertise and facilities we have at Chalk River Laboratories.
Under the FNST Work Plan, researchers at Canadian Nuclear Laboratories (CNL) carry out projects to support the Canadian government’s core responsibilities and priorities across the areas of health, safety and security, energy, and the environment.
