Astronauts Kate Rubins (left) and Jeff Williams (right) looking out of the ISS' cupola at a SpaceX Dragon supply spacecraft. Until recently, the effects of long-duration missions on eyesight was something of a mystery. Credit: NASA
Spaceflight takes a serious toll on the human body. As NASA’s Twin Study demonstrates, long-duration stays in space lead to muscle and bone density loss. There are also notable effects on the cardiovascular, central nervous, and endocrine systems, as well as changes in gene expression and cognitive function. There’s also visual impairment, known as Spaceflight-Associated Neuro-ocular Syndrome (SANS), which many astronauts reported after spending two months aboard the International Space Station (ISS). This results from increased intracranial pressure that places stress on the optic nerve and leads to temporary blindness.
Researchers are looking for ways to diagnose and treat these issues to prepare for future missions that will involve long-duration stays beyond Earth and transits in deep space. A cross-disciplinary team of researchers led by the University of Western Australia (UWA) has developed a breakthrough method for measuring brain fluid pressure that could reduce the risk of SANS for astronauts on long-duration spaceflights. This research could have applications for the many efforts to create a human presence on the Moon in this decade and crewed missions to Mars in the next.
NASA’s Orion spacecraft will carry astronauts further into space than ever before using a module based on Europe’s Automated Transfer Vehicles (ATV). Credit: NASA
In 2033, NASA and China plan to send the first crewed missions to Mars. These missions will launch every two years when Earth and Mars are at the closest points in their orbits (Mars Opposition). It will take these missions six to nine months to reach the Red Planet using conventional technology. This means that astronauts could spend up to a year and a half in microgravity, followed by months of surface operations in Martian gravity (roughly 40% of Earth gravity). This could have drastic consequences for astronaut health, including muscle atrophy, bone density loss, and psychological effects.
Aboard the International Space Station (ISS), astronauts maintain a strict exercise regimen to mitigate these effects. However, astronauts will not have the same option while in transit to Mars since their vehicles (the Orion spacecraft) have significantly less volume. To address this challenge, Professor Marni Boppart and her colleagues at the Beckman Institute for Advanced Science and Technology are developing a process using regenerative cells. This work could help ensure that astronauts arrive at Mars healthy, hearty, and ready to explore!
In a recent study published in Microbiome, a team of researchers led by NASA’s Jet Propulsion Laboratory conducted a five-year first-of-its-kind study investigating the microbiome (environmental profile) of the International Space Station (ISS). The purpose of the study was to address “the introduction and proliferation of potentially harmful microorganisms into the microbial communities of piloted spaceflight and how this could affect human health”, according to the paper.
A close up of three fruit flies, used for scientific research both on Earth and in space. Credits: NASA Ames Research Center/Dominic Hart
Space travel presents numerous challenges, not the least of which have to do with astronaut health and safety. And the farther these missions venture from Earth, the more significant they become. Beyond Earth’s protective atmosphere and magnetosphere, there’s the threat of long-term exposure to solar and cosmic radiation. But whereas radiation exposure can be mitigated with proper shielding, there are few strategies available for dealing with the other major hazard: long-term exposure to microgravity.
Aboard the International Space Station (ISS), astronauts rely on a strict regimen of exercise and resistance training to mitigate the physiological effects. These include muscle atrophy, bone density loss, organ function, eyesight, and effects on cardiovascular health, gene expression, and the central nervous system. But as a recent NASA study revealed, long-duration missions to Mars and other locations in deep space will need to be equipped with artificial gravity. This study examined the effects of microgravity on fruit flies aboard the ISS and demonstrated artificial gravity provides partial protection against those changes.
We recently explored how the Apple TV+ series, For All Mankind, gives us a harsh reality check about the harshness of human space exploration. In the show, astronauts struggle, some go crazy, and a lot of them die in the pursuit of planting our flag just a little farther from home. We discussed how while For All Mankind is both science fiction and takes place in an alternate universe, our future Artemis and Mars astronauts will very likely endure the same struggles and hardships as the show’s beloved characters.
When Artemis astronauts finally land on the Moon, they’ll be there anywhere from a few days to a few months. While the Moon is only a few days travel time from Earth, Artemis astronauts may still get a little cranky being stuck in their habitat and unable to go outside without a spacesuit.
In a recent study published in Space Physics, an international team of researchers discuss an in-depth study examining the long-term physiological effects of solar radiation on astronauts with emphasis on future astronauts traveling to Mars, to include steps we can take to help mitigate the risk of such solar radiation exposure. The researchers hailed from the United Arab Emirates, New Zealand, India, United States, Italy, Greece, and Germany, and their study helps us better understand the in-depth, long-term health impacts of astronauts during long-term space missions, specifically to Mars and beyond.
Ever since childhood, we were all told to never play with fire. Despite it being relevant to our everyday lives, to include heating our homes and water, cooking our food, producing electricity, and more, fire is extremely dangerous. We were all indoctrinated more with how to put out fires instead of how to start one. We’ve all been told about its destructive properties if mishandled, and that fire needs to be controlled. One of the perks of adulthood, and especially being a scientist, is you get paid to play with fire. Despite fire’s complexities, there’s still a lot we don’t know about its behavior. With more and more of humanity traveling to space and living in microgravity, it’s important to learn about how fire behaves in this unique environment to better prepare ourselves for worst case scenarios. But what if we could also control fire so it’s not as dangerous and less destructive to the environment back here on Earth?
The International Space Station in March 2009 as seen from the departing STS-119 space shuttle Discovery crew. Credit: NASA/ESA
Ever since astronauts began going to space for extended periods of time, it has been known that long-term exposure to zero-gravity or microgravity comes with its share of health effects. These include muscle atrophy and loss of bone density, but also extend to other areas of the body leading to diminished organ function, circulation, and even genetic changes.
For this reason, numerous studies have been conducted aboard the International Space Station (ISS) to determine the extent of these effects, and what strategies can be used to mitigate them. According to a new study which recently appeared in the International Journal of Molecular Sciences, a team of NASA and JAXA-funded researchers showed how artificial gravity should be a key component of any future long-term plans in space.
Lunar footprint from the Apollo missions. Credit: NASA
It’s been over forty years since the Apollo Program wrapped up and the last crewed mission to the Moon took place. But in the coming years and decades, multiple space agencies plan to conduct crewed missions to the lunar surface. These includes NASA’s desire to return to the Moon, the ESA’s proposal to create an international Moon village, and the Chinese and Russian plans to send their first astronauts to the Moon.
For this reason, a great deal of research has been dedicated to what the health effects of long-duration missions to the Moon may be – particularly the effects a lower gravity environment would have on the human body. But in a recent study, a team of pharmacologists, geneticists and geoscientists consider how being exposed to lunar dust could have a serious effect on future astronauts’ lungs.
Geologist and astronaut Harrison Schmitt, Apollo 17 lunar module pilot, pictured using an adjustable sampling scoop to retrieve lunar samples during the Apollo 17 mission in December 1972. Credit: NASA.
Because it has no atmosphere, the Moon’s surface has been pounded by meteors and micrometeroes for billions of years, which have created a fine layer of surface dust known as regolith. In addition, the Moon’s surface is constantly being bombarded by charged particles from the Sun, which cause the lunar soil to become electrostatically charged and stick to clothing.
Indications that lunar dust could cause health problems first emerged during the Apollo missions. After visiting the Moon, astronauts brought lunar soil back with them into the command module as it clung to their spacesuits. After inhaling the dust, Apollo 17 astronaut Harrison Schmitt described having symptoms akin to hay fever, which including sneezing, watery eyes and a sore throat.
While the symptoms were short-lived, researchers wanted to know what the long-term effects of lunar dust could be. There have also been indications that exposure to lunar dust could be harmful based on research that has shown how breathing dust from volcanic eruptions, dust storms and coal mines can cause bronchitis, wheezing, eye irritation and scarring of lung tissue.
Previous research has also shown that dust can cause damage to cells’ DNA, which can cause mutations and eventually lead to cancer. For these reasons, Caston and her colleagues were well-motivated to see what harmful effects lunar soil could have on the human body. For the sake of their study, the team exposed human lung cells and mouse brain cells to samples of simulated lunar soil.
After taking the first boot print photo, Aldrin moved closer to the little rock and took this second shot. The dusty, sandy pebbly soil is also known as the lunar ‘regolith’. Credit: NASA
These simulants were created by using dust samples from Earth that resemble soil found on the Moon’s lunar highlands and volcanic plains, which were then ground to a fine powder. What they found was that up to 90% of human lung cells and mouse neurons died when exposed to the dust samples. The simulants also caused significant DNA damage to mouse neurons, and the human lung cells were so effectively damaged that it was impossible to measure any damage to the cells’ DNA.
The results show that breathing lunar dust (even in minute quantities) could pose a serious health hazard to astronauts traveling to any airless bodies in the future. This includes not only the Moon, but also Mars and other terrestrial bodies like Mercury. Until now, this health hazard has been largely overlooked by space agencies seeking to understand the long-term health risks of space travel.
“There are risks to extraterrestrial exploration, both lunar and beyond, more than just the immediate risks of space itself,” said Rachel Caston. According to Bruce Demple, a biochemist at Stony Brook University School of Medicine and senior author of the new study, their results (coupled with the experience of the Apollo astronauts) indicate that prolonged exposure to lunar dust could impair airway and lung function.
What’s worse, he also indicated that if the dust induces inflammation in the lungs, it could increase the risk of more serious diseases like cancer. “If there are trips back to the Moon that involve stays of weeks, months or even longer, it probably won’t be possible to eliminate that risk completely,” he said.
Long-duration missions to the Moon, which could involve permanent bases, will have to contend with the hazard of breathing lunar dust. Credit: ESA/Foster + Partners
Ergo, any attempts to mitigate the risks of mounting crewed missions to the Moon, Mars, and beyond will have to take into account exposure to not only low-gravity and radiation, but also electrostatically charged soil. Aside from limiting the duration of missions and the number of EVAs, certain protective counter-measures may need to be incorporated into any plans for long-duration missions.
One possibility is to have astronauts cycle through an airlock that would also spray their suits with water or a compound designed to neutralize the charge, thus washing them clean of dust before they enter the main habitat. Otherwise, astronauts working in the International Lunar Village (or any other off-world habitat for that matter) may have to wear breathing masks the entire time they are not in a spacesuit.
Identical twin astronauts, Scott and Mark Kelly, are subjects of NASA’s Twins Study. Scott (right) spent a year in space while Mark (left) stayed on Earth as a control subject. Researchers looked at the effects of space travel on the human body. Credit: NASA
On March 1st, 2016, American astronaut Scott Kelly returned to Earth after spending a total of 340 days aboard the International Space Station (ISS). As part of NASA’s goal to send astronauts on long-duration space flights to Mars and beyond, this record-setting stay in space was designed to test the limit of human endurance in a microgravity environment.
Also known as the Twin Study, this experiment consisted of Kelly spending nearly a year in space while his identical twin (Mark Kelly) remained on Earth. Since Kelly’s return, the two have been subjected to medical tests to see what long-term effects microgravity has had of Scott’s Kelly’s physique. The final results of this test, which were just released, reveal that Scott has experienced changes at the genetic level.
The study was conducted by NASA’s Human Research Program, and the preliminary findings were released at their Investigator’s Workshop on the week of January 23rd, 2017. According to these findings, Scott Kelly showed indications of inflammation, changes in his telomeres and telomerase (parts of the chromosonal system related to aging), a decrease in bone density and gastrointestinal changes – all of which were expected.
NASA’s astronaut twins, Scott Kelly (l) and Mark Kelly (r). Image: NASA
As NASA reported in their preliminary findings:
“By measuring large numbers of metabolites, cytokines, and proteins, researchers learned that spaceflight is associated with oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts that affect gene expression… After returning to Earth, Scott started the process of readapting to Earth’s gravity. Most of the biological changes he experienced in space quickly returned to nearly his preflight status. Some changes returned to baseline within hours or days of landing, while a few persisted after six months.”
At the same time, the study took into account possible genomic and cognitive changes between the two brothers. These findings were recently clarified by NASA, which indicated that 93% of Scott Kelly’s genes returned to normal after he returned to Earth while the remaining 7% points were missing. These were attributed to “longer-term changes in genes related to his immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia.”
In other words, in addition to the well-documented effects of microgravity – such as muscle atrophy, bone density loss and loss of eyesight – Scott Kelly also experienced health effect caused by a deficiency in the amount of oxygen that was able to make it to his tissues, an excess of CO2 in his tissues, and long-term effects in how his body is able to maintain and repair itself.
At the same time, the report indicated that Scott Kelly experienced no significant changes when it came to cognitive performance. The preliminary findings touched on this, indicating that Scott showed a slight decrease in speed and accuracy when undergoing cognitive performance testing compared to his brother. This decrease was more pronounced when he first landed, but was attributed to readjustment to Earth’s gravity.
Mathias Basner – a professor at the University of Pennsylvania, Philadelphia, who was in charge of conducting the tests – also found no real difference in cognition between 6 month and 12 month missions. This is especially important since typical stays aboard the ISS last six months, whereas long term missions to Mars would take 150-300 days – depending on the alignment of the planets and the speed of the spacecraft.
A two way trip to Mars, as well as the time spent in Mars lower-gravity environment (37.6 % that of Earth’s), could take multiple years. As such, the Twin Study was intrinsic to NASA’s efforts to prepare for its proposed “Journey to Mars“, which is expected to take place sometime in the 2030s. These and other studies being conducted aboard the ISS seek to determine what the long-term effects on astronaut health will be, and how they can be mitigated.
The NASA Twin Study was the result of a partnership between 10 individual investigations, 12 colleges and universities, NASA’s biomedical labs and the National Space Biomedical Research Institute Consortium.
Scott Kelly’s stay in space and the Twin Study will also be the subject of a PBS documentary titled “Beyond a Year in Space“. Be sure to check out the teaser trailer here:
