In the long journey to Mars in the future, how will astronauts survive in the perilous space environment? In the medical box of the small space capsule, what are the most needed things to choose?
In the film and television works, space travel seems to be the most relaxing of the entire Mars mission. For example, Martian Mark Watney has always been in good condition, and the sandstorm is the severe test he encountered. Douglas Quaid’s journey to the Red Planet was also smooth sailing. He didn’t run into trouble until Mars Customs and Immigration Bureau. But in reality, space travel to and from Mars is fraught with danger, and of course it has nothing to do with extreme weather or gunmen.
The journey to Mars is very long. Four to six people have to live in a small and sealed environment for three years. After arriving at their destination, they will have to live on Mars for six to nine months. The journey back to Earth is also long.
Once the spacecraft is separated from the earth’s gravitational field and magnetic field, microgravity and radiation will be a big problem for astronauts to face. Microgravity causes the astronaut’s body fluids to accumulate on the head, which may cause vision problems. Spacecraft cruising in interstellar space will continue to withstand the impact of cosmic high-energy charged particles, which can even directly penetrate the metal shell of the spacecraft. Experimental data shows that radiation may increase the risk of cancer and other diseases for astronauts.
Prolonged space missions will also increase the health risks of astronauts. Compared with the Apollo mission, which only takes a few days to the moon, the trip to Mars is three years long, and the chances of astronauts experiencing social and psychological problems are much higher. The distance between Mars and the Earth is 600 times the distance between the Earth and the Moon. Even with the speed of light communication, it takes 20 minutes to reach the earth from Mars, so calling Houston for help in an emergency is not a good choice.
Despite all the dangers, the United States, Russia, China and other countries have all made plans to march on the Red Planet. NASA is preparing to complete a mission to Mars in the 2030s. Considering that time is tight, researchers are stepping up the development of a complete set of medical equipment and drugs needed for a trip to Mars.
At present, the items on this list are still in the early development stage, and some of them are still very unlikely to be realized. For example, the envisioned “universal diagnostic stick” is a distant dream. However, researchers are stepping up the design of artificial gravity suits, anti-radiation drugs and micro-medical tools. Scientists hope that these things will be ready in about 10 years to ensure the health and safety of the first Martian travelers.
Simulate gravity response to the microgravity environment of space
in microgravity, astronauts float easily in the air, it seems pretty easy and romantic. But in fact, long-term floating in a microgravity environment is extremely harmful to astronauts. In the case of severe weightlessness, the human body no longer needs to bear its own weight, and muscles and bones will gradually weaken. This has always been a big troublesome problem in the early space industry. In June 1970, when the crew of “Soviet Soyuz 9” returned from a record 18-day space trip, one of the astronauts was too weak to pick up his helmet as he exited the landing module. Today, astronauts on the International Space Station need to exercise for several hours a day to maintain their physical strength, but some other problems caused by living in a microgravity environment have not yet been resolved.
In the environment of weightlessness in space, the body fluids of the astronaut’s lower body will flow to the head, resulting in increased intracranial pressure. In this regard, researchers estimate that the continuous increase in pressure behind the eye is the main cause of vision problems. For example, the vision of about half of astronauts will develop into hyperopia in space. In addition, weightlessness will also cause confusion in the vestibular organs of the inner ear, which is sensitive to gravity. The vestibule of the inner ear plays an important role in human balance and movement control.
In order to ensure that astronauts can walk normally on Mars, the space capsule is equipped with artificial gravity machines. Among them, there is a device called “Lower Body Negative Pressure Chamber (LBNP)” which applies vacuum pressure to the lower body of the astronaut, generates a downward pulling force, firmly fixes the astronaut’s feet on the floor, and drains body fluids to Legs.
In an experiment, 10 volunteers implanted with intracranial pressure gauges sealed their lower body in LBNP. The volunteers had to lie down for the experiment to make the intracranial pressure close to the level in space. From standing to lying down on the earth, the intracranial pressure will rise from 0 mm Hg to about 15 mm Hg, which is closer to the experience of astronauts in space. The research report stated that as researchers slowly increased the vacuum pressure of the device, the average intracranial pressure of volunteers dropped from 15 mm Hg to 9.4 mm Hg.
Alan Hagens, a space physiologist at the University of California, San Diego, believes that it is unclear how long astronauts need to stay in the LBNP to protect their bodies from the harmful effects of fluid changes in the space environment. The Allen Hagens team produced a prototype of an LBNP suit that can be worn in daily activities. This lower body negative pressure device is an early form of artificial gravity, which is easier to send into space than the alternatives being tested (such as centrifuges). Obviously, launching a room-sized centrifuge is much more difficult than the LBNP suit. But other researchers believe that the function of the centrifuge can solve some microgravity problems that LBNP cannot solve, such as the vestibular problem of the inner ear.
Develop antioxidant drugs to solve the problem of the strong radiation in space
microgravity on astronauts to Mars could be a problem, but at least they are familiar with a challenge. But long-term exposure to deep-space radiation is an unknown danger that space travelers do not understand.
The solar system is full of charged particles called “galactic cosmic rays,” which travel almost at the speed of light. These particles can tear metal like torn paper towels, kill organism cells or trigger DNA mutations inside cells. Astronauts residing on the space station, like us on Earth, are largely protected by the Earth’s magnetic field and will not be harmed by these tiny particles. However, astronauts heading to Mars will be completely exposed to this dangerous radiation environment. On the way to the Red Planet, astronauts are expected to receive 2 mSv of radiation every day, which is equivalent to receiving a full-body CT scan every 6 days. .
In animal and human tissue testing experiments, it was found that simulated space radiation particle beams can degrade heart and blood vessel tissues, which indicates that Martian astronauts may face a higher risk of cardiovascular disease. In addition, experiments on rodents exposed to radiation have shown that space radiation can damage the cognitive function of animals. Although the amount of radiation exposure in animal and cell experiments is usually one or several weeks or months, it is equivalent to the radiation dose level received during the entire Mars mission, but this is not comparable to continuous, low-level exposure. The warning signals from these experimental results are indeed worrying, so researchers are testing various anti-radiation drugs.
The most promising drug candidates are antioxidants. High-energy charged particles will split water molecules in the body into toxic compounds called “active oxygen”, causing damage to the body. Injecting antioxidants can help neutralize some of the active oxygen and suppress its effects. Antioxidants of choice include vitamins A and E, and a selenomethionine found in some dietary supplements. These antioxidants can reduce the negative effects of radiation to varying degrees.
Of course, the protection of antioxidants alone may not be enough. Radiation biologists in the Department of Medical Sciences at the University of Arkansas are testing aspirin and other anti-inflammatory drugs to see if they can help reduce cell damage from high-energy particles.
Medical first aid kit configuration best to respond to unexpected
changes in the weightless environment by artificial gravity and taking antioxidants may astronaut will become part of everyday life, but also astronauts to Mars must learn to deal with any other unexpected illness and injury.
A doctor may be needed in the crew of astronauts on a mission to Mars, but the doctor may also be sick. Ideally, the space capsule should be equipped with artificial intelligence equipment, which can recommend medical tests, diagnose and determine treatment plans based on the symptoms of the astronauts, but it is still out of reach to develop a fairly reliable “Dr. AI” dream.
At present, the most advanced symptom detection tool is the diagnostic software VisualDx used by medical staff in hospitals and clinics, which can screen possible diagnosis results based on patient symptoms. For some skin diseases, VisualDx can also give a diagnosis based on the patient’s skin photos. The deep space system version designed on the basis of the VisualDx diagnostic tool can work on laptops that are not connected to the Internet. The software does not have to include all possible diagnosis results, only the diagnosis results that the astronaut has a higher chance of getting sick, such as skin rash or kidney stones.
In order for astronauts to quickly and easily learn how to first aid and do medical examinations, a team led by space flight physiologist and space medical scientist Douglas Ebert of the Houston KBR Company is developing a kind of “Autonomous Medical Support (AMOS)” The system tools, through pictures and videos, instruct beginners how to check their eyes and insert breathing tubes.
Researchers and about 30 non-professionals have studied and tested the AMOS prototype on several medical methods. About 80% of the volunteers can accurately perform eye examinations and ultrasound examinations, and about 70% of the volunteers can correctly complete intravenous injections. But for more difficult tasks, such as inserting a breathing tube, the success rate is only about half. In April 2020, astronauts on the International Space Station successfully used the software to complete ultrasound scans of the kidneys and bladder without the help of the ground control system.
In terms of medical imaging, space medical researchers set their sights on a portable Butterfly iQ ultrasonic device, which uses an electric shaver-sized probe instead of various sensors that are usually required to image different body parts. The standard ultrasonic equipment is approximately 15 times heavier than the movable Butterfly iQ ultrasonic equipment. In addition, 1Drop Medical Diagnostics is developing a credit card-sized chip to detect chemical markers of different diseases in finger prick blood samples, and is developing portable blood test equipment for astronauts.
Since astronauts’ medical kits must be pocket-sized, researchers are using NASA’s comprehensive medical model to determine what should be in the first aid kit in the capsule. This model can predict the most likely health problems of astronauts performing specific tasks. Researchers only need to enter mission details in the model, such as the astronaut’s navigation goals, gender, and health status, and then perform thousands of mission simulation runs to evaluate the probability of a crew member from constipation to heart attack to determine medical emergency Which medical supplies should be placed in the box first. At present, the research team has used this system to establish a preliminary list of first aid kit supplies for NASA’s manned lunar mission planned to be carried out in 2022.
Equipping a medical first aid kit for a trip to Mars will be a brand-new research topic, but researchers still have at least 10 years to “slim down” some medical equipment as much as possible, and determine the types of medical supplies to be equipped as soon as possible to give Mars space flight The greatest life guarantee for the personnel in the long and difficult space voyage.