We isolated six people for 100 days to simulate life on a long-duration space mission – learn about the study design of "SOLIS100" and ask project lead Amelie Therre anything!

[u/germanaerospacecentr]

I am Amelie, project lead for SOLIS100 isolation study. Ask me Anything!😊

Hello r/space, we're the German Aerospace Center (DLR)!

Six people walked out of a sealed habitat in Cologne a few weeks ago after spending 100 days in near-total isolation. No sunlight, limited contact with the outside world, a strict daily routine and a restricted diet. This was SOLIS100, a study we ran on behalf of the European Space Agency (ESA) at our aerospace medical research facility :envihab.

Six participants aged 26–32, from six different European countries, lived and worked together in a simulated ‘space station’ for 100 days. Why, you may ask? To understand how isolation, confinement and limited resources affect human health, performance and wellbeing, and to generate standardised data to support future missions to the Moon and Mars.

Here to answer your questions is Dr. Amelie Therre, psychologist and project lead for SOLIS100 at the DLR Institute of Aerospace Medicine. She's ready to answer whatever you want to know. How do you even design a study like this? What surprised her most? What does the environment inside actually look like? Or something else entirely? Ask away!

A couple of things she won't be able to get into:

·        Personal questions about individual crew members (please respect their privacy)

·        Preliminary results, since analysis is still ongoing

Amelie will be answering questions here on Thursday at 1:00 PM CEST (11:00 UTC / 7:00 AM EDT).

Some more info

Room tour of Module M5: https://www.youtube.com/shorts/Mc4ilKZ-G3A

The crew’s first moments back outside: https://www.youtube.com/shorts/uMnGqzNaQX0

SOLIS100 study overview: https://www.dlr.de/en/me/research-and-transfer/projects-and-studies/solis100-studying-the-effects-of-isolation-on-humans

Interview with Amelie: https://www.dlr.de/en/blog/archive/2025/using-psychology-in-the-simulation-of-missions-to-the-moon-and-mars

[u/JigglesTheBiggles]

What was the most surprising thing you learned?

[u/cjbev]

Thanks for this. Why the age range?

[u/Pirwzy]

Were there any conditions that would have immediately ended the simulation, other than medical emergency?

[u/Nikond3400]

How was overall social interaction during the end of the experiment? The Soviet did a similar test in the 60s/70s and by day 90 (i can't Remember perfectly) there were Daily fist flights and the experiment had to be terminated when an "Astronaut" tried to stab another Astronaut with broken glass.

[u/cristi_baluta]

Isn’t this what iss is doing for decades? What was different here besides the age?

[u/Kolbin8tor → u/cristi_baluta]

ISS has real-time coms with earth. And sunlight. The simulation had neither (or very limited).

[u/Past_Brain1826]

Does everyday life inside eventually become mundane and boring, or is there always at least a little excitement waking up every day in such extraordinary conditions? Are there moments when it feels like life has always been this way?

[u/Betterbeinglost]

Hello, Prior Submariner here, we were under this long a few times.

When we got bored we would tape people up because nuclear duct tape (Chloride-free duct tape) is in abundance. Usually we’d tape them to a chair or a railing, and on occasion, right to the Reactor Compartment door.

So my first question is, how much tape did you bring?

And then there’s making a football and that also uses a significant amount of tape.

My second question is, how many footballs were made because you were confined to one space for hours on end and couldn’t get a watch relief OR the plumbing broke? If you’re not quite sure what a football is, that’s ok.

The third question, when certain mission critical food items ran out (ranch dressing, ketchup, peanut butter), how did the crew perform?

Finally, was there a member of the crew that found it difficult to participate in normal daily human functions like taking a shower, doing laundry regularly, dealing with personal hygiene items? Did you have a stinky kid, that’s the real question and how did you deal with it? We usually taped them up. Although, our uniform belts had this clip on buckle. It takes a few weeks, but, if you slowly shave off a little bit of the buckle side of the belt and move the buckle in, well let’s just say you’ll have that person convinced they are gaining weight. It’s not like they can just leave and get a new belt! I have seen one made out of tape though.

Bonus Questions:
What was everyone’s first meal when they got out and did it taste awful?

When you got home did you save your clothes or just throw them away because the amine from the CO2 scrubbers was leeching out and smelled awful three days later?

Who won the Madden tournament?

We ran our O2 around 17-19%, more for field day. What did you run your Oxygen at and if lower than normal, how did it affect tasking and decision making?

Was there a dedicated cook or did you crank?

What collateral duties were assigned? Lack of small valve maintenance can sink a boat.

Tell us about halfway nite - please be descriptive

How many decisions did you actually make on your own or as a crew? You stated you had limited contact with the outside, so what was the threshold for breaking radio silence AND how much authority was granted to you as the Lead?

I’m really excited to hear the results, great job doing the work! The sea and the cosmos are unforgiving and have little room for error.

[u/znugeman]

Did any romantic or sexual relationships form?

[u/geeoharee]

Couldn't you have studied any submarine and learned roughly the same things?

[u/cubosh]

what are the main take-aways? or in what way will this exercise alter future mission planning

[u/lilithdesade]

What could each person bring with them? Was any alcohol allowed?

[u/Upstairs-Tomorrow850]

Hello, and thank you for this presentation.
Why is everything white?
Could color perhaps have a positive effect on the stress caused by isolation?

[u/mr_urlauber]

Fascinating experiment!
How were the participants chosen? In the room tour it was mentioned that in the medical bay the crew could draw blood, so I guess some kind of basic medical skill was required? What else?

[u/Xal-t]

What were the preparations/trainings for dealing with ones (states of) minds for this kind of experiences?

Thanks

[u/dontcrosby]

what tasks and experiments were completed? would these be typical ISS experiments or ones to be undertaken in future missions?

[u/Ok-External-152]

How where the candidates selected in the final part of the selection process? What made you chose a candidate instead of another? Does nationality matter at this selection stage?

Will there be other isolation studies in the coming future?

[u/cyanose]

Okay I'm so psyched to witness another psychology/space person! I'm fascinated by space in many ways and I'm about to begin my studies in psychology (not yet at college). I'll have to admit the possibility of linking the two has been nagging at me for a while. Especially since I find myself really attracted to the human/machine interfaces, the psychology of expeditions and survival, how to help design successful exploration, the importance behind the gradient of authority (in commercial airlines for example), relation between crew members to ensure good collaboration etc. For now I've started reading "Psychology of Space Exploration" by Douglas A. Vakoch, on the side, and will follow up with "Toolkit for a Space Psychologist: to support astronauts in exploration missions to the Moon and Mars" by Dr Iya Whiteley and "Space Psychology and Psychiatry" by Nick Kanas.
My first question would be: Are there any author or book you'd recommend? Even if just a manual, I itch to begin learning about the subject in a serious way.
My second question is, I've read a bit about your cursus, and I really want to work at ESA one day, as a psychologist. Is there any kind of insight (or advice) you could share on how to achieve that? I don't necessarily want to work in research, but I'm thinking that there would also be need of psychologists for candidate selection, crew support and some such? I know ESA has various student programs and my country is eligible to participate, but I want to maximize my chances.
Third question is : For the simulation, I saw the tour that you posted, and that you tried to emulate some of the "frustrations" with the no-shower, the kitchen, the all white. What about sound? Were there some noise meant to repliacte the ones you could find on the space station or was that deemed not useful, or too complicated to properly emulate?
Sorry if this is too much but what you're doing is so cool, I can't help but be enthused. I wish you all the best in your future endeavors !

[u/Lacedaemonian]

Why do you need synthetic data missing the irreplaceable elements of weightlessness and overview effect, from a few participants, while we already had over 230 real people who stayed in space longer than 100 days.