We're signing off. Thanks for joining us and for all of your great questions! Watch our new videos for more info: http://www.nasa.gov/content/exploring-space-through-you-omics

My short bio: NASA’s Human Research Program is conducting a Twins Study on retired twin astronauts Scott and Mark Kelly. The study began during Scott Kelly’s One-Year Mission, which encompassed International Space Station Expeditions 43, 44, 45 and 46. Now that Scott has returned from space researchers are integrating data as well as taking measurements on Earth from the twins. This is the first time NASA has conducted Omics research on identical twins. Comparing various types of molecular information on identical individuals while one undergoes unique stresses, follows a defined diet, and resides in microgravity to one who resides on Earth, with gravity, should yield interesting results. It is hoped one day that all individuals will have access to having their Omics profiles done. This is a first step towards personalizing medicine for astronauts and hopefully for the rest of us. Ask us anything about the Twins Study and Omics.

For background, check out NASA’s Omics video series at https://www.nasa.gov/twins-study.

*Kjell Lindgren, M.D., NASA astronaut, Expedition 44/45 Flight Engineer and medical officer

*Susan M. Bailey, Ph.D., Twins Study Principal Investigator, Professor, Radiation Cancer Biology & Oncology, Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine & Biomedical Sciences, Colorado State University

*Christopher E. Mason, Ph.D., Twins Study Principal Investigator, WorldQuant Foundations Scholar, Affiliate Fellow of Genomics, Ethics, and Law, ISP, Yale Law School, Associate Professor, Department of Physiology and Biophysics, Weill Cornell Medicine

*Brinda Rana, Ph.D., Associate Professor, Department of Psychiatry, University of California San Diego School of Medicine

*Michael P. Snyder, Ph.D., M.D., FACS, Twins Study Principal Investigator, Stanford W. Ascherman, Professor in Genetics, Chair, Dept. of Genetics, Director, Center for Genomics and Personalized Medicine, Stanford School of Medicine

My Proof: http://nasa.tumblr.com/post/142813680869/twins-study-reddit-ama

Comments: 674 • Responses: 101  • Date: 

Debatable_Dogma682 karma

May you please accelerate one twin to near-light speed so we get a real-life demonstration of the twin paradox?

JSCNASA426 karma

Help us figure out how to do this! - kjell

JSCNASA303 karma

yes yes!! -cm

JSCNASA155 karma

So far Scott Kelly has only aged slightly less (just a fraction of a second -about 0.014s), but the twin paradox will need new technology to get there. http://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter13.html -CM

boyl0043523 karma

What do the Twins need to do to turn their season around? Especially after that devastating sweep by the Nationals...

JSCNASA307 karma

Hire astronauts! MS

michael1026319 karma

Was Scott Kelly chosen for the year in space partly because he had a twin? Or was it chosen to do this study because it was a good opportunity since he'd be in space for an extended period of time?

JSCNASA572 karma

Scott was chosen independent of having a twin. The idea of the Twin Study actually came from the twins themselves after Scott was selected. Susan

cooldude0027134 karma

Do you dress them in certain colors to tell them apart?

JSCNASA225 karma

Shortly after launch, for April Fool's Day Mark shaved and fooled folks. susan

Herp_derpelson190 karma

Shortly after launch, for April Fool's Day Mark shaved and fooled folks. susan

Was it more "hey guys, I'm back early", or "oh crap, I missed my flight!"

JSCNASA158 karma

the later ;)

aww213130 karma

If you cut both twins in half could you recombine them into two new people?

JSCNASA131 karma

Current evidence suggests this is unlikely, but twins are a version of cloning! :-) -Chris Mason

korainato116 karma

Which results of your study surprised you the most?

JSCNASA212 karma

The results will not come out for another year, but what surprised me was how hard it is to collect samples in space and also how hard it is to process them! MS

TopGouda9865 karma

What were some of the biggest challenges?

JSCNASA174 karma

1) How hard it is/was for Scott to actually do a blood draw in zero gravity 2) How to process the samples to separate the blood cells from the blood fluid and freezer the samples. You cannot pipet in space so that makes everything complicated. MS

JSCNASA92 karma

Not hard at all. I stood by to help, but all of the crewmembers did their own blood draws. We put the samples in a centrifuge and then in the freezer. - kjell

JSCNASA35 karma


Check out this video too! http://www.youtube.com/watch?v=VmhEtPN5u9Y

Hard to do when the tubes are floating around. -CM

JSCNASA29 karma

We don't really have any results yet - the study will go for a number of months after Scott's return. Susan

Tgclark106 karma

One science fiction concept, seen in tales such as The Expanse series or The Moon is a Harsh Mistress, is that humans born in a micro gravity environment are unable to visit Earth because their bodies cannot withstand a full G. Has NASA's research on the effects of long-term spaceflight validated this concept, or is it just an interesting plot device?

JSCNASA171 karma

I'm a fan of Heinlein's work. Authors and artist's like Heinlein help us imagine and prepare for the future of our species in space. We haven't validated the concept that humans born in weightlessness couldn't return to earth. There is much research to do. We don't even know if a human conceived in weightlessness would develop normally in the weightless environment, much less survive 1-g as an adult. - kjell

JSCNASA62 karma

If humans were born and lived their whole life on a planet with different gravity, this would lead to very different tolerances and physiological response to other gravity, just as we would find it very hard to walk in 2X gravity ourselves. So, yes, it's likely a real thing! -CM

eatmyboot95 karma

Was the twin on Earth (Mark) technically aging faster than the twin on the space station (Scott) ?

JSCNASA182 karma

The question of aging/the twin paradox often comes up - will Scott return younger than Mark? Because the ISS is not traveling at the speed of light away from us, the effect of time dilation will be very minimal (way less than a second).. The telomere study is the first time NASA has evaluated a biological marker of aging - we believe that Scott will age more than Mark due to the stresses and radiation exposures associated with space flight.. susan

JSCNASA56 karma

Relative to Scott, we all were (including Mark)!

JSCNASA41 karma


Ithaisa65 karma

How could assess the epigenetic effects of environmental space in a human being?

JSCNASA81 karma

This is done in several ways: First, we will examine the effects of modification of Scott's DNA over time. DNA modification (DNA methylation) and the modification of the material that packages DNA (histones) are affected by the nutrients we eat, stress, exercise and other conditions. We will examine whether and how Scott's DNA and his DNA packaging material gets modified during space travel. Second, the ends of people's chromosomes (ie telomeres) are affected by age and stress. We will see if telomeres get shorter in Scott relative to Mark. MS

Mrrodgersss53 karma

Aliens, yes or no?

JSCNASA133 karma


Jux_53 karma

How far did the Kelly boys get in their plotting to pull an ISS-Switcheroo on astronuats Lindgren and Yui?

JSCNASA44 karma

There was no switcher-roo as far as i can tell. It was amazing to get to fly with Scott and to be a part of the one-year mission. kjell

Exaskryz46 karma

What is the information you are most interested in collecting? What hypotheses of yours are you excited about testing?

JSCNASA74 karma

Personally I am hoping to see the impact of space travel on the human DNA and RNA, including the measurement of the impact on the "epigenetic clock" https://en.wikipedia.org/wiki/Epigenetic_clock, the non-coding RNAs that may be activated that we have not seen before, and nucleic acid base modifications (DNA and RNA!). And of course, the microbiome will be full to look at. And maybe a retrotransposon that is activated in zero-G! https://en.wikipedia.org/wiki/Retrotransposon -CM

JSCNASA45 karma

For me, I'm interested in the effects of space flight (experiences, exposures) on aging - and therefore the increased risk of developing the degenerative diseases that go along with it (e.g., cardiovascular disease, cancer). susan

JSCNASA35 karma

I also would like to see the effect of space travel in epigenetics and whether it is reversible. MS

truthaboutcs45 karma

What do you think about the movie Predator?

JSCNASA81 karma

Get to the choppa! - kjell

JSCNASA77 karma

Thermographic vision is rumored to exist in some astronauts too. But they are not evil, so it's ok for them to have it. But such vision could help find leaks in space stations or habitats, and it could have been useful for The Martian: http://www.imdb.com/title/tt3659388/ -CM

JSCNASA49 karma

Movies like predator inspire (or occasionally terrify) us about what the future could like. The artists that create these movies help us dream, innovate and create our own futures. Movies like 2001, The Right Stuff, Apollo 13 and Star Wars inspired me to dream of a future in low earth orbit. - kjell

imtheashley41 karma

I follow Scott on Instagram and one day he posted a video of him being electrocuted for testing. It looked very painful! What was that test for and why was it important?

JSCNASA54 karma

I'm not sure about the nature of that exact experiment, but i imagine that it had to do with electrical stimulation of muscles. - has to do with figuring out if muscle weakness is due to muscle atrophy or less recruitment of muscle fibers by the nervous system. - kjell

AeroMech6430 karma

Hey Kjell! I saw you at Marshall 2 weeks ago for the NASA Student Launch. You're a real inspiration to my rocketry team.

I was curious about injuries in space vs. on Earth. How common are injuries on the ISS, compared to typical Earth injuries like stubbing a toe or getting a paper cut? Is there special equipment specifically for microgravity to deal with bleeding or open wounds?

How will researchers evaluate the possible effects on the study if say Scott got a unique injury on the ISS or Mark was injured on Earth?


JSCNASA29 karma

Hey AeroMech64! It was a privilege to chat with you all at the SLI. We can still get injured in space. We have to be especially careful when doing resistive exercise ('weight' lifting). It is very easy to torque your back or a shoulder. Skin abrasions are pretty common too. No special equipment to deal with injuries - mundane bandaids and antibiotic ointment. thanks for the questions! -kjell

codydschultz30 karma

Also, to curb the degenerative effects of microgravity, has NASA considered transport ships that create artificial gravity using centripetal forces from a rotating station like the one from the film, The Martian or Interstellar?

JSCNASA47 karma

We have no plans that i know of to build a ship with artificial gravity at this point. But I've heard Scott Kelly express the opinion that for missions longer than a year, we really need to think about AG. - kjell

JSCNASA39 karma

Related to your question about a rotating station to curb the effects of microgravity....Centrifugation-based artificial gravity on the human body have been conducted. NASA is preparing to conduct another ground study of simulated microgravity (head down tilt bed rest) with and without centrifugation to study if "spinning" to create artificial gravity is an effective countermeasure of the detrimental effects of microgravity. BR

JustALittleGravitas27 karma

How has recovery proceeded in comparison to shorter flights?

JSCNASA38 karma

I've spoken with Scott about his recovery, and he would say that his recovery is taken longer. - kjell

noraa72724 karma

Are there any drug based treatments being developed to help combat the effects of long term exposure to micro-gravity during space travel?

JSCNASA26 karma

drug based treatments have to be targeted to specific changes caused by weightlessness - bone loss, cardiovascular deconditioning, vestibular changes, radiation exposure. we have done research looking at pharmaceutical treatments for many of these - kjell

noraa72712 karma

Which of those changes ,if any, appears to be the most pressing issue?

JSCNASA29 karma

I think that radiation exposure is the most challenging problem for a safe and successful trip to Mars. A pharmaceutical countermeasure could be one useful part of a larger suite of tools to counteract radiation's effects. - kjell

noraa72714 karma

Last question I promise ! How to you pharmaceutically counteract the effects of radiation? do you somehow shield the DNA molecules to keep them from being altered ?

JSCNASA22 karma

In some types of radiation exposure - for example internal exposure from radioactive iodine - prophylactic consumption of potassium iodide can prevent uptake into the thyroid and subsequent types of cancer. There may be some pharmaceutical countermeasures that we can use to limit DNA damage from heavy galactic cosmic radiation. Help us figure this out!

JSCNASA20 karma

Exposure to space radiation has the potential to be a show stopper as we make our way to Mars - longer periods of time deeper and deeper in space. Susan

JSCNASA13 karma

Our groups are conducting studies to investigate the effect of a number of potential "countermeasures" against the effects of microgravity (e.g. bone loss, muscle loss, orthostatic intolerance upon landing). These countermeasures includes exercise interventions. Other investigations include hormone (testosterone) treatment. - Brinda

recentfish21 karma

  1. How was it determined which of the Kelly brothers would spend the year aboard the ISS and which would stay on Earth?

  2. I’ve read that there will be more studies about how astronauts fare physiologically on long flights in a few years. Have you learned anything yet from Scott Kelly that will change how long stays on the ISS will be conducted in the future?

JSCNASA42 karma

  1. Mark retired a few years ago. Scott was an active ISS astronaut at the time of his assignment, so he was naturally the one to get to go to space.
  2. It takes a while to collect scientific data, evaluate and publish it. We will be publishing the results of this year in space for years. He has provided terrific anecdotal details of his experience already - kjell

willrunfordonuts21 karma

Did Mark Kelly follow the same diet and exercise routines as Scott during the year apart? I.e. How certain are you that the differences observed in the "omics" data will be due to the differences in gravity environments?

JSCNASA34 karma

Mark Kelly did not have the same diet of space food or exercise routine as Scott - he was living a fairly normal life on earth, as compared to a life in space. Observed differences will not be due only to microgravity - rather the combined/integrated effects of spaceflight. susan

codydschultz19 karma

Has this study been able to help develop or contribute to personalized medicine for the masses?

JSCNASA27 karma

This study is helping to create the most detailed molecular map of the changes in the body over time (DNA, RNA proteins, small molecules, cognition, vasculature, epigenetics, epitranscriptome, protein changes), and the process of making and then integrating these data will be used for methods on patients here on Earth too (cancer patients, aging, normal longitudinal monitoring of health). It is basically the longest-term "wellness" study to date, and more are coming that can use this framework. Similar to this paper: http://www.ncbi.nlm.nih.gov/pubmed/22424236. -CM

Fighting_the_Foo14 karma

I had a question that's not really related to the study, but have been wondering. Do you constantly "feel" like you are falling while in orbit? As in the feeling of weightlessness in a free fall.

JSCNASA25 karma

No, you feel like you are floating! It is awesome. - kjell

8236413 karma

What environmental factors did you control for? Or was the point to keep the twins in wildly different conditions? I've read both things.

To YOU, what invokes Clarke's Third Law?

JSCNASA18 karma

Spaceflight is altogether different from living on Earth. In addition to weightlessness, the atmospheric composition (CO2 levels), ambient noise levels, stress levels, etc. There are A LOT of variables. Having twins available for this study allows us to evaluate the data in ways that we wouldn't otherwise be able to. As for Clarke's Third Law - being in weightlessness. I understand the physics, but it feels like magic! kjell

Beer-Here13 karma

How will this study control for differences in nurture (e.g. different diets, habits, etc. that may affect gene expression) that existed before the space flight between the twins? What role, if any, will phenotypic plasticity play in the analysis?

JSCNASA17 karma

Mark and Scott are about as similar in nature and nurture as you can get - identical twins, both astronauts. All of the studies conducted baseline data collection to establish where they were before space flight. susan

JSCNASA13 karma

Since we will have six months of measurements before flight, as well as six months after the mission, we will measure and model the changes and their variance and also compare them to hundreds of other data sets of expression and -omics that we have from other controls. The plasticity is a key factor! -CM

VRtual11 karma

How will this data be used to forward the Journey to Mars?

JSCNASA11 karma

A better understanding of the health effects of long duration space flight will give us direction in mitigating deleterious effects as we journey to Mars. susan

chayashida10 karma

Has anyone on the team played Kerbal Space Program? The computer game has reinvigorated my interest in space and space science.

Also, after playing, I started hearing more of the science in the conversations in movies like The Martian.

What do you think of mass media and the depictions of NASA?

JSCNASA13 karma

The Kerbal space program and the depictions of space in film and books are great ways to inspire and educate. I think depictions of NASA and spaceflight in mass media really depend on the author/director and what they are trying to accomplish. Science fiction inspired me to pursue this dream! - kjell

onexistence8 karma

I don't have a twin, but can you still send me to outer space? Pretty please!

JSCNASA17 karma

I don't have a twin either and I got to fly! Work hard and pursue your dreams! - kjell

rholcs128 karma

How can you decide that any changes between Scott and Mark are because of the effects of spaceflight rather than diets, activities of Mark, or just plain growing old. As a twin myself, are there any studies that my twin and I could help?

JSCNASA8 karma

This is similar to the question above. Diet is hard to control for since they both eat different things, but the hope is that by following the same person over time we will see the changes that occur in each twin. Generally people eat pretty similarly over time so we will what changes occur in Scott when he is in space relative to when he is on the ground and that should help, but it is possilbe some of the effects will be due to "sapce food". MS

Slatersaurus7 karma

Which one is the evil twin?

JSCNASA4 karma

need to ask them this one ;) susan

JohnbeiHaleygami7 karma

Fellow former Ram here with sights on space work. What was the most difficult obstacle in the recruitment process for you to overcome?

JSCNASA7 karma

Go Rams! There are many obstacles, but there are also many opportunities to support human spaceflight. Find the career or area where you have talent and passion (especially in the STEM domain) and work hard! - kjell

JSCNASA3 karma

Go Rams! susan

mrsejo7 karma

Commander Kelly reported some immediate effects from his space journey being extreme body fatigue and skin irritation. What are you current plans to reduce these for future space flights?

Also, thank you for doing this. You're all inspirations, I hope you have a great Monday!


JSCNASA8 karma

we have a lot of work to do to address some of the things that Scott has reported since his return. We are still in the data gathering mode and looking forward to applying these lessons to future missions. - kjell

astronaut_jupiter7 karma

Hello! I am 14 years old an have been an aspiring astronaut for 4 years. I incessantly doubt myself and feel as if I'm not qualified for this career or lifestyle. To overcome this doubt I work harder and harder in my studies. From this I get confirmation from my conscience assuring me that I am doing things right. I experience the same doubt sooner or later. My dad has been telling me that that the amount of time I devote to my studies and studying physics could potentially become unhealthy. To solve this my dad started taking me to Zumba class lol. What suggestions do you have for me? Do I continue to use this process? Did you experience the same thing as a child?

JSCNASA10 karma

It is important to have a sharp mind and a healthy body too; both are needed for being an astronaut. And you also need an advanced degree (e.g. Ph.D.) and so you will need to plan ahead for a while and keep studying! -CM

JSCNASA8 karma

It's a good idea to develop all aspects of yourself and body--your brain, your physique, and your behavioral and emotional side. Study hard and engage in other activities you enjoy, especially physical activities. After all, your whole body, not just your brain, is engaging to solve those physics problems. Physical activities in which you interact with others is a bonus because they can help you develop the social and team work skills you'll need to be an astronaut. BR

tHarvey3035 karma

Does the fact that the astronauts take steps to counter the effects of zero-gravity (exercise to keep up bone density/lower muscle atrophy etc) affect your results?

Thanks for the AMA.

JSCNASA6 karma

The countermeasures conducted by the astronauts are well documented so we will take that in account in our analyses. BR

PaneerTikaMasala5 karma

Have you noticed any psychological/personality changes being away from each other for so long? If so, what quirks have change or have manifested? I'm curious to understand if there has been any changes to your brain chemistry even though this will all be a qualitative and personal assessment of each other. Thank you for your service!

JSCNASA5 karma

There are behavioral tests that are administered. I do not know the results. Only blood chemicals are measured (not brain) so we do not know directly, but it is possible to follow many key compounds important for human behavior in the blood. MS

SKatieRo4 karma

I'm a twin. Can you please send me into space?

Actually , what was the most surprising thing you have learned so far?

JSCNASA5 karma

In the words of Scott Kelly "Space is hard" and that space flight is a team effort.. It really does take an entire community of engineers, scientists, doctors, etc. etc. etc. to ensure success and safety of our astronauts. susan

r___b3 karma

How much the twins’ life were similar during the experiment? e.g. Did the twins ate the same food, sleep during the same time?

JSCNASA6 karma

Their lifestyles were not similar during the one year mission. Mark led typical earth life, Scott led typical space life. susan

basicallytherock3 karma

Do you think simulated Gravity is in the future of space flight?

JSCNASA8 karma

To mitigate adverse health effects - yes. susan

MattBaster2 karma

Can they still finish each other's sentences after spending so much time apart?

JSCNASA6 karma

I'm not sure they were able to finish each other's sentences before flight! In light of their military service and deployments, this year was probably not the longest that they have spent apart - kjell

StormCrow17702 karma

Would it be possible to conduct the experiment again with younger twins?

JSCNASA5 karma

Possible if younger twins - both astronauts - were identified/selected. susan

schrodinger452 karma

Do you have any plans as to how you will validate or re-investigate interesting results you come across?

JSCNASA3 karma

We will be comparing to all other samples that have been in space and have molecular data, and cells/samples are all banked for follow-up validation and investigation later. Currently all twins samples are in replicate labs across the country to ensure redundancy. -CM

JSCNASA5 karma

Also a lot of the data is in NASA's GeneLab: http://genelab.nasa.gov/ -CM

JSCNASA2 karma

I would expect that similar studies will be performed on astronauts in the future. Of course, they may not be twins, but we can still follow them before takeoff, during the mission and after return. MS

drchaker2 karma

Have you ever had doubts regarding how useful this experiment will be for practical purposes? I am not downplaying any aspect of this experiment and I think this has been a remarkable achievement for mankind. I am asking for your opinion of how you feel towards humanity's ability to take advantage of this research in the future.

Also, do you think this needs to be repeated?

JSCNASA4 karma

I have no doubts. Every person we study longitudinally has a lot of value--we see how people change in time and response to stress. There are other studies like this in which other sorts of stress and being examined on people so we can see how the effect of stress Scott's experiences will compare to that of other--ie what types of stress are genral and which ones are specific to space.

We definitely need more of these studies repeated. What we learn form this study will teach us how to perform these studies better in the future.

JSCNASA3 karma

The twins study builds the foundation for future studies as we venture further and farther into deep space. The power will come from the combined studies - data sharing between all investigations. It is a remarkable opportunity! susan

imreadyforoligarchy2 karma

Did you find any anthrax on the ISS?

JSCNASA12 karma

no, i don't care for heavy metal music. - kjell

Seaman1821 karma

Are there any psychological/neurological tests planned? Seems there's a lot to look at there... The effects of altered blood flow to the brain is an obvious one, along with the sensory changes that come with a close-quarters zero-gravity environment (proprioception especially).

There's also the general isolation/small social circle thing, but that's less novel as it can be seen with submarines and such as well.

JSCNASA2 karma

There is indeed a lot to look at! There are behavioral and cognitive studies being conducted and planned on astronauts and simulated microgravity studies on the ground. These will certainly complement the "Fluid Shifts" studies which investigate the flow of blood and fluids towards the head in the microgravity environment. BR

JSCNASA2 karma

There are behavioral surveys performed before, during and afterwards. I do not know the results of these. MS

Maureen59001 karma


JSCNASA2 karma

As a geneticist it is awesome- having twins is the best way to tease out nature/nurture differences, and we expect to see the areas of the body and molecular changes that are most impacted by space travel, so we can plan for ways to mitigate and protect against them. -CM

makemeking7061 karma

Twins are not identical, even "identical" twins, in numerous and important ways. Even if one is exposed to the "treatment" and the other is not, how does the team intend to reliably estimate treatment effects and rule out selection bias from unobserved pre-existing differences?

JSCNASA2 karma

The advantage of analyzing samples over time is that we should be able to follow changes in detail. Although there are many things that we do not measure, the things we measure we measure in all samples and this will allow us to follow the effects of space. MS

crimzinvegan1 karma

On the issue of microgravity, extra blood flow and blood volume in the head can cause headaches, correct? What are the headaches caused by, is it just the increased intracranial pressure or is there a heat factor causing pain? Also what kind of headaches do the astronauts have? Migraine? Tension? Is their head hurting all of the time, or does the pain go away? Does NASA currently allow headache /migraine headache sufferers to become astronauts? And have they done any studies on the effects of microgravity on people who already have headaches?

JSCNASA3 karma

The headward fluid shift is just one of the physiologic changes that occure in weightlessness. Some astronauts have headaches and the fluid shift may be a part of that. the elevated carbon dioxide levels on the ISS may be a contributor as well. I didn't really have headaches, just a sense of head 'fullness' that improved over time, but never really went away. - kjell

Relurker1 karma

Kjell Lindgren, how did you go about becoming an astronaut?

JSCNASA3 karma

Hard work! I'm grateful for all of the folks that were a part of my journey - my family, teachers, mentors and coaches. Becoming an astronaut is not an individual accomplishment - it is a reflection on all of the folks who make flying to space possible. I kept the dream of becoming an astronaut as an overarching dream, but pursued a career where I had talent and a passion - in emergency medicine. I continued to explore ways to work in human spaceflight as a physician, studied aerospace medicine and became a flight surgeon at Johnson Space Center. I was very fortunate to get selected as an astronaut in 2009. - kjell

rearwilly1 karma

How close to "normal" (bone, muscle and any other things that change) is Mark compared to before he went into space? Will this factor into the results vs. Mark never having been in space?

JSCNASA1 karma

Both Mark and Scott are astronauts and their changes due to space travel is documented. We collected physiology data before and after space travel. These data will be considered in our final analyses. BR

Ericabneri1 karma

Kjell, how many photos did you take compared to the amount put on twitter/released etc?

JSCNASA2 karma

I probably posted 1 out of every 500 that i took. I hope you enjoyed the photos i shared! - kjell

giraffeman911 karma

Would the team rather fight one Scott sized Mark or 100 Mark sized Scotts?

JSCNASA4 karma

both, and then compare the battles with genomics measures. -CM

JSCNASA2 karma

Ditka - kjell

ZacPensol1 karma

I know the results won't be ready for a while, but were there any immediately-obvious changes that Scott underwent? I know he has mentioned that he's taller due to the lack of gravity compressing his joints (though that will fade, if it hasn't already).

JSCNASA3 karma

Facial puffiness and visual acuity changes are common in astronauts. BR

mjmax1 karma

Are there any plans for longer experiments? What about partial gravity experiments (spinning ISS modules, assuming you had infinite budget)?

JSCNASA3 karma

I hope so. MS

Wolpfack1 karma

Did you collect radiation data, such as SPE and GCR events, as a correlation factor in your studies?

JSCNASA5 karma

There are radiation monitors on the ISS, and the astronauts wear personal dosimeters - Kjell has a good story about that. So, yes, we will have information about the particular exposures they experienced and correlate with our findings. susan

Undeadgamr191 karma

Did the twins ever since each other's pain or danger while Scott was in space?

JSCNASA4 karma

not that i know of - kjell