By Andy Tomaswick March 6, 2025
Skeptics love to bring up one particular topic regarding long-term human space exploration - radiation. So far, all of the research completed on it has been relatively limited and has shown nothing but harmful effects. Long-term exposure has been linked to an increase in cancer, cataracts, or even, in some extreme cases, acute radiation poisoning, an immediate life-threatening condition. NASA is aware of the problem and recently supported a new post-doc from MIT named Robert Hinshaw via the Institute for Advanced Concepts (NIAC) program. Dr. HHinshaw'sjob over the next year will be to study the effectiveness of an extreme type of mitochondria replacement therapy to treat the long- and short-term risks of radiation exposure in space.
The project, known as MitoMars, is based on a radical idea that is relatively easy to explain. It focuses on mitochondria, known only half-jokingly on the internet as the "powerhouse of the cell." While these little organelles provide energy to the cell, they also play some critical roles in other cellular functions like calcium signaling and, importantly, apoptosis, the planned cellular death mechanism that fails when a cell turns cancerous.
Mitochondria are also heavily affected by radiation - they also have DNA, which is separate from the DNA used in the rest of the cell. However, they also lack the repair mechanisms to recover from damage to those DNA strands from radiation, making it much more likely for them to become non-functional and eventually kill the cell. Radiation also has several other insidious ways of affecting mitochondria, making this valuable cellular member one of the most susceptible parts of a human to the effects of the radiation flowing about in interplanetary space or on the surface of other planets without a magneto or atmosphere.
Anton describes how terrible space is for our cells.
Credit - Anton Petrov YouTube Channel
MitoMars is trying to fix those problems. But instead of repairing them inside the body, the plan would be to take a sample of the astronaut's mitochondria before they are put into the radiation environment, send those mitochondria with them in a protected vessel, and then use those mitochondria as replacements if / when the ones that remain in their body become damaged by radiation.
Think of it as saving up liters of blood before a big operation. When the operation happens, the surgeons can use the blood you had saved up to replace any blood lost during the surgery with your own blood, limiting the risks of rejection or other complications. In this case, the replacement bodily fluid would be with you in space, in a protected container, so it's not exposed to the same risks as the rest of you.
MitoMars has a pretty ambitious goal. However, Phase I is almost always baby steps, and that is the case here as well. In Phase I, Dr. Hinshaw plans to purposefully damage some in-vitro human cells with radiation, presumably at the NASA Space Radiation Laboratory, where he collected data as a graduate student. After the cells are damaged enough, he will attempt to restore cellular function by replacing the cell's mitochondria via replacement therapy.
Dr. Afshin Beheshiti and Dr. Spring Behrouz discuss the impact on mitochondria from being in space.
Credit - Vincere Bio YouTube Channel
After collecting data on how the cells respond to the treatment, Dr. Hinshaw plans to develop a therapy regime for use in flight, potentially allowing astronauts to treat themselves on long-duration missions to the Moon and Mars.
This project might be particularly appealing to NASA because it has obvious implications for more near-term technology applications here on Earth as well. Radiation has become a part of our everyday lives, from X-rays to cancer therapy, and mitochondrial damage has increased along with it. If MitoMars successfully develops a mitochondrial replacement regime that could help astronauts in space, it could also be applied to people suffering from the ill effects of radiation on Earth.
Whether the replacement therapy will actually improve cell repair remains to be seen. But if you’re interested in the success of long-term human exposure to space conditions, keep an eye on MitoMars and similar work on the effects of space radiation—studies like this are how humanity will eventually overcome its biggest hurdle, stopping us from more exposure to the stars.
Learn More:
NASA - MitoMars: Targeted Mitochondria Replacement Therapy to Boost Deep Space Endurance
NASA - Mitochondrial Changes Key to Health Problems in Space
UT - Health Issues from Space Flight Might Originate in the Mitochondria
UT - Astronauts' Muscle Loss Mimics Age-Related Muscle Loss