About 70% of astronauts deal with space sickness in the first three days of spaceflight. This condition isn’t quite the same as motion sickness on Earth, so astronauts and mission planners need to really understand it to keep missions on track.
Space Motion Sickness (SMS), or Space Adaptation Syndrome (SAS), hits when astronauts enter microgravity environments. Nearly 70% of space travelers get it as their bodies try to figure out weightlessness.
SMS usually shows up within the first 72 hours of being in space. Most astronauts start feeling better after 3 to 5 days, once their bodies adjust.
It’s honestly one of the most common medical headaches for space crews. If your inner ear works normally, you’re probably going to feel at least a little off during those first few days.
Key Stats:
When astronauts come back to Earth, the problem can pop up again. The first 10 days after landing can feel pretty weird as the body readapts to gravity.
Space sickness can really mess with an astronaut’s ability to work safely. The main symptoms? Nausea, vomiting, dizziness, and vertigo.
Physical Symptoms:
Cognitive Effects:
Vomiting in space is especially risky. If it happens inside a spacesuit, it could lead to choking or damage the life support gear.
Some astronauts only feel mildly uncomfortable, but others get hit so hard they can’t do their jobs until things settle down.
Mission Impact: Space agencies won’t schedule spacewalks during the first few days. If someone gets really sick, it could mess with emergency plans or even basic spacecraft operations.
Space sickness isn’t just car sickness in zero gravity. Sure, both involve your senses getting mixed up, but the causes are pretty different.
Terrestrial motion sickness happens when your eyes and inner ear argue about whether you’re moving. For example, in a car, you might see a still seat but feel the motion.
Space Motion Sickness works differently. In microgravity, the vestibular system can’t sense gravity anymore. The otolith organs in your inner ear, which usually know which way is down, just stop working the way they should.
Key Differences:
| Terrestrial Motion Sickness | Space Motion Sickness |
|---|---|
| Conflicting motion signals | Loss of gravitational reference |
| Usually predictable triggers | Happens even if you’re still |
| Closing your eyes can help | Looking away doesn’t fix it |
| Stops when motion stops | Stays as long as you’re weightless |
The sensory conflict theory covers both, but the details flip. On Earth, your body’s surprised by unexpected movement. In space, your brain expects gravity but gets nothing.
Microgravity also pushes fluids up toward the head, which can mess with the inner ear’s balance. That doesn’t happen on Earth.
Space sickness starts when the body’s sensory systems stop working together the way they do on Earth. The vestibular system in the inner ear can’t find gravity anymore, so the brain gets mixed signals about balance and movement.
The vestibular system relies on otoliths—tiny organs that sense gravity and straight-line movement. On Earth, these move when you tilt your head, telling your brain where you are in space.
In microgravity, otoliths lose their sense of direction. The usual signals from the hair cell receptors just don’t help anymore. This throws off the balance between the left and right sides of your head.
Fluid redistribution makes things worse. Without gravity, blood and other fluids shift into the head. That messes with pressure in the inner ear and can throw off your balance even more.
The brain tries to interpret these weird signals. Movements that used to mean “I’m tilting” now get misread as “I’m moving sideways.” That’s the root of space sickness.
According to the sensory conflict theory, space sickness happens when your senses give your brain different stories. On Earth, your eyes, ears, and body usually agree about where you are.
In microgravity, the vestibular system starts sending confusing messages. Meanwhile, your eyes still work the same way. The brain just can’t sort out whether you’re moving, tilting, or floating still.
This sensory mismatch sets off the same brain circuits that cause motion sickness on Earth. The parts of your brain that try to combine sensory info—like the thalamus—just get overloaded.
Astronauts can see their environment perfectly well, but their inner ears are basically lying to them. That’s what makes the nausea and confusion so tough.
In space, astronauts lose their natural sense of up and down. The brain’s model of gravity, built over a lifetime, just doesn’t work up there.
Spatial disorientation shows up in strange ways. Some astronauts feel like they’re falling or spinning, even when they’re floating still. Others think the whole spacecraft is turning.
The brain’s balance and orientation centers can’t adapt instantly. Areas like the temporoparietal junction just get stuck with conflicting info they can’t resolve.
This confusion doesn’t just make astronauts feel sick—it can slow down their thinking and make tasks harder. It usually takes two to five days before the brain figures things out in microgravity.
Not everyone gets space sickness the same way. Age, genetics, and your history all play a part, but microgravity brings its own set of triggers that you just don’t see on Earth.
Age matters a lot for space motion sickness. Younger astronauts tend to have a tougher time than older ones. Studies suggest you get less sensitive to motion sickness as you get older.
Gender also affects space sickness. Women often report stronger symptoms and take longer to adapt than men.
Genetics can make you more or less prone to space sickness. If your family gets motion sick easily, you might too.
Sleep deprivation makes symptoms worse. Astronauts who don’t get enough rest before launch usually struggle more during their first few days in space.
Stress and anxiety don’t help either. If you’re stressed or naturally anxious, you’re more likely to get hit hard by space adaptation syndrome.
Getting carsick doesn’t predict space sickness. Just because you get queasy on road trips doesn’t mean you’ll have trouble in orbit.
People with migraines seem to have a rougher time. If you’re prone to headaches, space adaptation syndrome might hit you harder.
Earth-based motion sickness meds don’t always work in space. The reasons for space sickness aren’t quite the same, so astronauts need different treatments.
Boat and airplane sickness don’t really match up with space symptoms. The vestibular system just reacts differently to zero gravity.
First-timers usually get it the worst. Astronauts who’ve been up before tend to handle it better the next time.
Quick head movements can set off symptoms instantly in microgravity. Astronauts have to learn to move slowly, especially at first.
Stressful mission tasks make things worse. High-pressure situations can push symptoms over the edge.
The cramped, artificial environment of a spacecraft adds to the confusion. Limited space and odd lighting don’t help your senses adjust.
Vomiting in a spacesuit is dangerous. It can lead to choking or mess up life support gear, especially during spacewalks.
Space sickness can slow down mental performance. That’s a problem when astronauts need to make fast, critical decisions.
Astronauts use practical strategies and mission rules to get through those first tricky days in space. The main idea is to limit demanding activities and let the body adapt.
During the first 72 hours, crews move slowly and carefully to avoid triggering space sickness. Gentle, deliberate head turns help keep the sensory systems from freaking out.
Mission control plans out easy orientation tasks and makes sure astronauts avoid quick spins or fast changes in direction.
Rest and smart positioning matter a lot. Astronauts find stable spots in the spacecraft and use handholds to keep from drifting around.
Staying hydrated is important, too. Even if they feel sick, astronauts sip fluids often to avoid dehydration.
Focusing on fixed points inside the spacecraft helps. Looking out the window at moving objects can make things worse, so astronauts stick to interior views at first.
Space agencies don’t allow high-risk activities in the first few days. No spacewalks or extra-vehicular activities take place until the crew adapts.
This policy keeps astronauts safe. Vomiting or getting disoriented during a spacewalk could be fatal.
Crews also hold off on tricky technical tasks. Major maneuvers and dockings wait until everyone’s back to normal.
Flight planners build these breaks into mission schedules. Only real emergencies make them break the rules during the adaptation period.
Astronauts train for these limits and know the timeline will flex to fit the body’s natural adjustment to microgravity.
Space agencies turn to specific medications to help astronauts manage motion sickness. Some drugs work better than others in microgravity, but dosing and side effects require careful attention since they can affect how well astronauts perform.
Promethazine is the go-to medication for space motion sickness among astronauts. As an antihistamine, it helps cut down on nausea, vomiting, and dizziness—problems that hit about 70% of space travelers during their first three days in microgravity.
NASA usually gives astronauts intramuscular promethazine as the standard treatment. This drug blocks histamine receptors in the brain that would otherwise trigger motion sickness.
Scopolamine is another option astronauts use to prevent space motion sickness. It comes as a patch and offers longer-lasting relief by affecting how the vestibular system deals with conflicting sensory input.
Astronauts can also turn to dimenhydrinate and meclizine if the main treatments don’t work well or cause side effects. These are also antihistamines and help manage symptoms when needed.
Space medical teams choose medications based on how each astronaut tolerates them and what the mission requires. Since options are limited in a spacecraft, picking the right drug really matters for mission success.
Space medicine protocols lay out specific dosing schedules for these medications. Astronauts usually get 25 milligrams of promethazine by intramuscular injection if symptoms show up, with repeat doses every 6-8 hours if necessary.
Scopolamine patches deliver a steady dose through the skin. Medical teams stick these patches behind the ear 4-6 hours before symptoms might start, and they can protect astronauts for up to 72 hours.
Oral medications like meclizine are given in 25-50 milligram doses, usually 1-2 hours before any activity that could trigger symptoms. Timing is crucial in microgravity because drug absorption can be unpredictable.
For severe symptoms, intramuscular injections are the top choice. This method gets the drug into the system reliably, even if astronauts are too sick to keep down pills.
Medical officers on board keep a close eye on how astronauts respond and adjust doses as needed. They log every detail about medication effectiveness, which helps improve future mission protocols.
Space motion sickness meds can really mess with astronaut performance. Promethazine often leads to drowsiness, dry mouth, and poor coordination—none of which are ideal when you’re handling critical tasks.
Scopolamine brings its own set of problems, like confusion, memory lapses, and vision issues. These side effects can get in the way of complex procedures or emergency responses.
Both drugs can make fine motor work tough. Medical teams have to weigh the benefits of symptom relief against how much the drugs might slow someone down during each mission phase.
Drowsiness from antihistamines is especially tricky during launch and landing. Space agencies sometimes ban certain meds during these times to keep everyone sharp.
Inside a spacecraft, options for dealing with bad reactions are limited. Astronauts can’t just stop a medication if it’s causing trouble, since alternatives might not control symptoms well enough to keep the mission on track.
Astronauts don’t just rely on medications—they use physical training and mental techniques to fight space sickness, too. These methods help the body adjust to microgravity using controlled exercises and stress management.
Space agencies train astronauts with specific exercises before launch to get them ready for microgravity. Head and body spinning drills get the inner ear used to the weird disorientation that causes space sickness.
Pre-flight Training Programs Astronauts do rotation exercises on Earth before heading up. It’s all about teaching the vestibular system to handle confusing signals.
Environmental Controls on Spacecraft Modern spacecraft come with systems that reduce things likely to trigger motion sickness:
During the space shuttle program, crew members who moved their heads regularly in flight reported fewer symptoms. Galvanic vestibular stimulation—using tiny electric currents—can help retrain the balance system.
Astronauts stick to slow, careful movements during their first days in space. This gives their brains a chance to process all the new sensory input.
Mental strategies play a huge part in managing space sickness. Stress reduction helps astronauts control their body’s reaction to microgravity.
Breathing and Relaxation Techniques Diaphragmatic breathing kicks in the body’s relaxation response. Studies show it can ease nausea and dizziness in space.
Astronauts practice slow, controlled breathing to lower their heart rate. That helps keep anxiety—and symptoms—at bay.
Psychological Adaptation Methods Mental prep is key. Astronauts learn to expect symptoms and come up with ways to push through them.
Some space programs even try acupuncture before flight. It might help reduce how sensitive astronauts are to motion sickness triggers.
Visualization exercises let astronauts mentally rehearse being in microgravity. This kind of practice helps reduce the shock when they actually get there.
Successful space missions depend on thorough medical screening, specialized training, and custom medication protocols. NASA and commercial space companies put a lot of effort into preparing astronauts for the unique challenges of microgravity.
NASA runs detailed medical evaluations to spot astronauts who might be prone to space motion sickness. They use vestibular function tests and check for motion sensitivity.
Medical officers check each astronaut’s inner ear function with special equipment. These tests see how the vestibular system reacts to different movements and changes in orientation.
Training programs put astronauts through simulated space conditions using parabolic flights and spinning environments. These sessions help build up tolerance to the sensory confusion microgravity causes.
Centrifuge training creates fake gravity to get the nervous system ready for space. Astronauts go through several sessions to help their bodies adapt before the real thing.
New crewmembers get special training to help them handle space motion sickness. This includes autogenetic feedback training and head rotation exercises.
Virtual reality systems let astronauts experience the kind of sensory conflicts they’ll face in space. These sessions give them a chance to practice managing disorientation before it’s real.
Tilt-transition devices help astronauts get used to not having a clear sense of “up” or “down.” The equipment slowly exposes them to the kinds of confusion they’ll feel during their first few days in orbit.
NASA has new astronauts complete several training cycles before their first mission. Each round builds on the last, strengthening their ability to adapt.
Crew medical officers test anti-motion sickness medications on each astronaut before assigning them to a flight. They watch closely for how well promethazine and scopolamine work and for any side effects.
Drug sensitivity tests help find the right dose for each astronaut. Medical teams look for problems like drowsiness or poor coordination that could hurt mission performance.
Preflight testing sometimes includes trying out drug combinations—pairing anti-nausea meds with stimulants to balance symptom control and alertness.
NASA keeps detailed records on how each astronaut responds to medications over multiple missions. This info helps refine drug protocols and predict what each person will need in the future.
Space motion sickness brings some real operational headaches. It can threaten crew safety and even put the whole mission at risk. Astronauts lose alertness, spacewalks get delayed, and teams have to plan carefully around adaptation periods.
Space motion sickness is dangerous during high-stakes mission phases. Vomiting in a space suit isn’t just gross—it can block helmet visibility and even create choking hazards.
Symptoms can mess with mental performance and alertness, especially when astronauts need to think fast. Coordination and decision-making suffer during emergencies.
Main safety risks include:
Space suit systems can break down if bodily fluids get inside, and there’s no way to clean up in a hurry. Astronauts sometimes have to keep working with contaminated gear.
Cognitive issues hit mission-critical tasks like docking and navigation. Around 70% of astronauts deal with these symptoms, so it’s not a rare problem—it’s something teams expect.
Extra-vehicular activities (EVA) often get pushed back during the first few days in space. NASA doesn’t allow spacewalks in the first 72 hours because of motion sickness risks.
EVA needs sharp coordination and spatial awareness, which just isn’t possible if you’re dizzy or disoriented. Astronauts can’t work outside the spacecraft or handle tools safely until symptoms ease up.
Mission timelines get stretched when crew members can’t do their jobs as planned. Repairs and experiments have to wait until everyone’s back to normal.
A short EVA window can throw off the whole mission schedule. Teams must juggle activities, which affects everything from orbital mechanics to ground control timing.
Space missions depend on precise timing for things like rendezvous and landing. If astronauts are too sick, mission control sometimes has to delay or cancel these maneuvers until the crew recovers.
Most astronauts need three to five days to fully adapt to microgravity and get back to peak performance. This adjustment period can really squeeze short missions, where every day matters.
Crew productivity drops a lot during the first days in space. Even seasoned astronauts feel off their game as their bodies adjust.
Mission planners have to build in time for this adaptation when scheduling important tasks. It’s tough to front-load missions with essential activities when the crew isn’t at full strength.
Adaptation timeline:
Returning to Earth brings its own adaptation problems. Landing and post-flight tasks can be tough, and astronauts often need extra recovery time.
When astronauts come back from space, their bodies have a tough time getting used to gravity again. Recovery means dealing with dizziness, nausea, and balance problems—and following rehab routines to get back to normal.
Astronauts often get Entry Motion Sickness (EMS) within minutes of hitting Earth’s gravity. The symptoms are a lot like what they felt during their first days in space, just in reverse as their bodies readjust.
Common readaptation symptoms:
The vestibular system needs time to recalibrate after floating in microgravity for months. Inner ear hair cells have to relearn how to sense gravity’s pull.
Longer missions make EMS symptoms worse. Astronauts coming back from six-month stays on the International Space Station have a rougher time than those on short trips.
Medical teams focus on relief:
Recovery usually takes a few hours to a few days, depending on how long the mission lasted. The first 72 hours after landing are the trickiest for most astronauts.
Astronauts rely on structured rehabilitation programs to get back to normal physical function after long periods in weightlessness. These programs target body systems that microgravity affects.
Medical teams keep a close watch on astronauts during the readaptation period. They use balance and coordination tests to check recovery.
Rehabilitation components include:
Physical therapy starts as soon as astronauts get back. Therapists walk astronauts through exercises that gradually restore function on Earth.
Rehabilitation usually follows a stepwise approach. Early on, the focus is on basic mobility and balance. Later stages work toward full recovery.
Ground-based analog studies give medical teams insight into readaptation challenges. Experiments with rotating rooms and centrifuges shape rehab protocols.
Most astronauts recover normal function within weeks. Some issues, like bone density loss, might need months of focused treatment.
Space motion sickness has a lot in common with terrestrial motion sickness, but microgravity brings new hurdles for the vestibular system. Car sickness and seasickness affect about 25-30% of people, but space motion sickness hits around 70% of astronauts during their first three days in orbit.
Car sickness kicks in when passengers get mixed signals from their inner ear and eyes. The vestibular system senses motion, but the eyes focus on still objects inside the car.
Seasickness bothers travelers when ships move and constantly change gravitational orientation. Rolling and pitching motions create sensory conflicts, sometimes even more complex than in cars.
Air sickness pops up during turbulence or quick altitude changes. Commercial flights rarely cause it because they’re usually smooth, but military and small planes are a different story.
All these types of motion sickness share similar symptoms. People first feel a bit off or tired, then nausea and dizziness can set in. In bad cases, vomiting and total incapacitation follow.
Both space and terrestrial motion sickness come from sensory conflict theory. The brain gets mismatched signals from the vestibular system, vision, and proprioception.
Common triggers include:
Space motion sickness brings its own set of triggers. Microgravity removes the brain’s normal reference point for gravity, so the vestibular otoliths can’t sense up or down.
In zero gravity, fluids shift toward the head. This causes pressure changes in the inner ear—something you just don’t see on Earth.
Space travelers can’t just step outside for relief like car or boat passengers. The microgravity environment sticks around 24/7 until the body finally adapts or the mission ends.
Scopolamine patches work for both space and sea sickness. NASA relies on them, and cruise passengers use the same patches.
Promethazine is effective in space but causes drowsiness, which is a problem for drivers or pilots on Earth. Astronauts can rest during adaptation, but that’s not an option for everyone.
Ginger supplements help a bit with car and sea sickness, but they’re not strong enough for space motion sickness. Microgravity just overwhelms ginger’s benefits.
Habituation training works for all types. Rotating chair exercises reduce sensitivity to space motion sickness, and similar balance training helps with car and sea sickness.
Antihistamines like meclizine give moderate relief on Earth. In space, results vary because microgravity changes how drugs work.
Scientists keep making progress with new drug treatments and training methods to fight space sickness. NASA and other agencies are trying out fresh ideas that could make space travel easier for everyone, astronauts or not.
Research teams are coming up with new drug combos that fight space sickness without making astronauts sleepy. Old meds like scopolamine and promethazine work, but they leave people drowsy and dizzy.
Now, scientists are testing anti-nausea drugs mixed with stimulants like amphetamine. This combo keeps nausea in check and helps astronauts stay sharp during important tasks.
Current drug research focuses on:
Some journal studies suggest personalized medicine might work better than a one-size-fits-all approach. Not every astronaut responds the same way to each drug.
Researchers look for biomarkers to predict which treatments will work for each person. This could help doctors pick the best medication before launch.
New delivery methods—like nasal sprays and skin patches—get drugs into the bloodstream faster than pills.
Training programs now use virtual reality and special gadgets to help astronauts get used to weightlessness before they even leave Earth. These methods build tolerance without drug side effects.
Non-drug treatments include:
Head and body rotation exercises help astronauts adjust to mixed signals from their inner ears. These sessions usually run for several weeks before launch.
Tilt-transition devices put trainees through sudden position changes like those in space. Research says these methods can cut space adaptation syndrome symptoms by up to 40%.
Stroboscopic vision training uses flashing lights to mess with normal visual processing. The brain learns to handle mixed signals from different senses.
Ground-based studies with parabolic flights and rotating rooms test these methods. Results show pre-flight training can really shorten and lessen space sickness.
NASA’s Human Research Program calls space motion sickness a major knowledge gap that needs fast action. Current studies look at long missions to Mars, where old treatments might not cut it.
The International Space Station serves as a lab for new treatments and monitoring systems. Astronauts try different meds and training, and researchers track what happens.
Active research areas include:
NASA teams up with places like Baylor College of Medicine to push space medicine forward. These partnerships share data and test methods across programs.
Recent studies look at how space sickness affects mission-critical tasks in the first 72 hours. This helps define minimum crew effectiveness for emergencies.
Scientists work on automated systems that track astronaut symptoms without constant medical checks. These tools will be crucial for deep space trips where you can’t call home for help.
Researchers are pushing for advanced solutions tailored to each astronaut’s needs, using the latest tech. They’re focusing on custom treatments based on genetics and rolling out smart monitoring systems during missions.
Medical teams work on custom space sickness treatments for each astronaut’s biology. Age, sex, and genetics all play a role in who gets sick and how badly.
Scientists look at DNA markers to predict who will get nausea, dizziness, and vomiting in microgravity. This info lets doctors pick the right meds ahead of time. Some astronauts do better with promethazine, others need scopolamine or something else.
Pre-flight testing now includes detailed checks of vestibular function and motion sensitivity. Teams use rotating chairs and other tools to see what each person can handle. This data shapes treatment for specific missions.
Hormone levels matter, too. Researchers develop therapies that time medication based on hormone cycles and stress.
New monitoring devices keep tabs on astronaut health in real-time during missions. Smart sensors track heart rate, temperature, and movement to catch early signs of space sickness.
Wearable tech includes patches that deliver meds through the skin at just the right times. These gadgets adjust dosing automatically based on symptoms and mission needs. Virtual reality headsets retrain the brain’s balance systems with controlled visual exercises.
Spacecraft design is getting an upgrade to reduce motion sickness triggers. Better ventilation and lighting help keep circadian rhythms normal. Some missions will test artificial gravity systems using rotation for longer trips.
Mobile health apps let astronauts log symptoms and get instant treatment advice. Machine learning algorithms study patterns across missions to improve future prevention.
Space Motion Sickness affects about 70% of astronauts and space travelers in the first 72 hours of microgravity. Both medication and non-drug methods help manage symptoms like nausea, dizziness, and disorientation during spaceflight.
Promethazine and scopolamine are the go-to medications for Space Motion Sickness. They both cut down nausea and vomiting during space missions.
Promethazine blocks certain brain receptors that trigger symptoms. NASA astronauts use it most during the first few days when symptoms peak.
Scopolamine patches deliver medication through the skin, keeping symptoms under control without needing to swallow pills—which is tough when you’re already nauseous.
Medical teams sometimes pair anti-nausea meds with stimulants. This combo fights drowsiness but still keeps symptoms in check.
Pre-flight training puts astronauts in rotating environments and altered gravity. These sessions get the brain ready for mixed sensory signals.
Centrifuge training brings artificial gravity, simulating some aspects of space motion sickness. Astronauts practice tasks while feeling disoriented.
Head movement exercises on Earth help build up tolerance to vestibular disruption. Controlled rotations train the inner ear for microgravity.
Gradual adaptation protocols tell astronauts to move slowly during the first days in space. These techniques help reduce symptoms.
Promethazine is the top anti-nausea medication for space. Studies show it works well in both real and simulated microgravity.
Scopolamine also does a good job at preventing symptoms before they start. The patch format is handy in zero gravity, where swallowing pills is tricky.
Dimenhydrinate and meclizine offer alternatives for astronauts who can’t take the main meds. They work in similar ways but have different side effects.
Some combination meds include amphetamine to offset drowsiness. This keeps astronauts alert while controlling symptoms during critical times.
Tilt-transition devices put trainees through quick orientation changes, building tolerance to sensory conflicts.
Autogenic feedback training teaches astronauts to control their physical responses to motion stress. Breathing and relaxation techniques can lower symptom severity.
Rotating chair exercises provide controlled vestibular stimulation during ground training. Regular sessions help the brain adapt to mixed signals.
Head rotation protocols during training specifically target the inner ear organs that get disrupted in space.
Light, easy-to-digest foods help cut down nausea during the worst phase of space sickness. Astronauts skip heavy or fatty meals in the first few days.
Staying hydrated is key. Dehydration makes nausea worse and can drag out motion sickness.
Small, frequent meals work better than big portions. This keeps nutrition up and stomach upset down.
Ginger supplements look promising for natural nausea relief in space. Some programs include ginger in pre-flight prep.
Virtual reality systems can actually mimic the visual-vestibular conflicts that often trigger space motion sickness. Astronauts get exposed to these disorienting visual environments while they’re still on the ground.
Some VR protocols throw people into scenarios where what they see doesn’t match what they feel. This kind of sensory conflict training nudges the brain to get used to the weirdness of microgravity.
There’s also stroboscopic vision training with VR, which scrambles up normal visual processing. People use these exercises to build up a tolerance for the visual disturbances that pop up during space adaptation.
Research so far? Results are all over the place when it comes to VR’s effectiveness in preventing space sickness. Scientists definitely need to run more studies to figure out the best training methods and how long astronauts should train.
