A comment below the question How will they mitigate the effect microgravity in the BFR on manned trip to mars? suggests that the trip might be as short as 3 months, which is significantly shorter than the typical 5-6 months spent on the ISS. So far, it seems that it is likely to be a similar microgravity environment with no Coriolis-laden rotation for artificial gravity.

There will be more radiation since Earth's magnetic field will be far behind, and that's been well discussed on this site and a bit by Elon Musk; for energetic solar events there will likely be shielded areas where the occupants can retreat for the duration.

So it sounds like while there may be "nicer" accommodations (e.g. "cabins", perhaps even with reasonable facsimiles of doors instead of what they have now (see GIF and GIF) will the physical environment "feel" in any way significantly different on an interplanetary mission than an orbital one?

I can't think of anything beyond the availability of specific creature comforts that might be installed, are there any that would be the direct result of differences between an Earth-orbit experience and an interplanetary experience?

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    $\begingroup$ I mean obviously the role of a BFS Mars trip is different than the ISS, one is for science, the other is to get somewhere. If there's around 60 people on board, they're gonna get pretty bored eventually. I'd wager the people will spend their time studying Mars know-how, working out, consuming entertainment, and doing teambuilding activities / socializing. I'd also imagine that your average BFR passenger would be under drastically lower stress, have lots of free time, and get plenty of rest compared to the rigorous sleep-work cycle on the ISS. $\endgroup$
    – Dragongeek
    Commented Mar 1, 2018 at 11:53
  • $\begingroup$ @Dragongeek I can imagine those things, but I"m asking about things related to the period of time being spent specifically in interplanetary travel rather than spent in orbit around the Earth. As an aside, there's no way to be sure at the moment that the trip in a tin can with 59 other people might not end up being far more stressful, rather than drastically less, but that would be a different question. $\endgroup$
    – uhoh
    Commented Mar 1, 2018 at 12:09
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    $\begingroup$ @uhoh On the psychological side, very good analogs can be drawn with Amundsen Scott base, particularly the "winter over" crew of about 45 which stay there for half a year with zero supplies in or out (no planes or anything). The only difference from that to a Mars journey is the South Pole people have more space, slower-but lower latency-internet, and gravity. $\endgroup$
    – Dragongeek
    Commented Mar 1, 2018 at 14:20
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    $\begingroup$ I've been doing a lot of thinking and some research on this subject for a future novel project, however I don't have a factual answer as nobody really knows. Even at the south pole in the dead of winter they can drop supplies and they even picked up a cancer patient once. $\endgroup$
    – GdD
    Commented Mar 2, 2018 at 8:44
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    $\begingroup$ That's it exactly @uhoh. $\endgroup$
    – GdD
    Commented Mar 2, 2018 at 11:30

2 Answers 2


One key difference in health impact is that an astronaut who needs surgery on a trip to Mars will need to be treated by their crewmates, in microgravity, using whatever equipment is on board, and with many months until they return to Earth. This is in contrast with on the ISS, where medical emergencies can be evacuated to the ground in hours to days. (This option has so far never been needed, but having it available does reduce the amount of preparation and equipment needed.)

Depending on how successful the as-yet-untried art of appendectomies in freefall turns out to be, the difference in health impact may be large.

  • $\begingroup$ Scientists over-wintering on the smaller antarctic bases have their appendices and wisdom teeth removed before they go. I am sure the same would be appropriate for a Mars trip. $\endgroup$ Commented Sep 25, 2018 at 17:01
  • $\begingroup$ So basically we need a doctor in the... well, not house, but interplanetary vessel? $\endgroup$ Commented Sep 26, 2018 at 2:39

Update: Just a few days ago MIT held a workshop on this topic. From Psychology Today's Stressed? Just Imagine Going to Mars; Workshop to explore loss of privacy, use of digital technologies in space.

The first astronauts needed the Right Stuff as they launched into Earth orbit. A new generation of astronauts will need much more as they travel to the Red Planet, facing unprecedented stresses on their much longer missions. This week researchers will gather in Cambridge, Massachusetts to develop concrete ways to design spacecraft to be hospitable environments. “Future space missions take crew members further and longer from the comforts of Earth in space flight vehicles that are relatively smaller compared to the International Space Station. These isolation and confinement hazards create behavioral health and performance risks to the crew that we want to address in a meaningful way with habitable vehicle design,” said Dorit Donoviel, director of the Translational Research Institute for Space Health (TRISH), which is sponsoring the meeting Spaces in Space: Optimizing Behavioral Health and Cognitive Performance in Confined Environments. The workshop, called Space2 for short, will take place February 6-7, 2019 at the MIT Media Lab, which is also sponsoring the event. Sessions will be freely available by livestream for anyone who registers.

Spaces in Space: Optimizing Behavioral Health and Cognitive Performance in Confined Environments

NASA has recently addressed this in a series of web pages and podcasts

The block-quoted text is from the Seeker article Hre Are the Five Biggest Dangers NASA Astronauts Face which draws directly from those five NASA podcasts and transcripts linked abvoe.

Radiation can lead to cancer and other serious health problems:

NASA is also looking at countermeasures to reduce radiation risk during long missions.

“If you can get there faster, that’s probably the biggest thing... because that minimizes the time you have to spend in space,” says NASA scientist Zarana Patel in the podcast. So more efficient propulsion might be one way to reduce exposure. Future spacecraft could also make use of magnetic shielding to protect the crews. Or perhaps there’s another technology out there that hasn’t been invented yet.

Isolation is really tough on your psychological health:

Seniors, people with disabilities, and people living in harsh environments all face a similar issue — isolation. If there are few options to leave your house and see other people and participate in what many consider “normal” life, it’s difficult for humans to function psychologically. In space, that isolation is also extreme. Astronauts must remain inside of a small space station for six to 12 months at a time, only going “outside” during a spacewalk — and that’s if they’re lucky and have one scheduled.

“We’re very resistant and adaptable to different changes in our environment,” says NASA scientist Tom Williams. “And what isolation does is sort of remove that context of adaption, because when we’re isolated, we’re not being able to engage our environment in as many different ways as we are when we’re not isolated. And so, therefore, some of the things that we depend on to help us adapt to the different challenges that we may encounter are now removed from that.”

[...] One sign of crew stress shows up in how they sleep. One research study cited in the podcast showed that in a sample size of 21 people, crews on the space station aren’t sleeping well roughly 29% of the time. (To put that in time perspective, that’s roughly two months out of a six-month mission.) NASA is still trying to figure out how to help astronauts adapt to isolation and a strange environment.

Time delays when calling home increase emergency problems:

NASA already has its crews trained in basic medical procedures in space, so they can deal with many common issues by themselves. This not only cuts down on superfluous calls to the ground, but the astronauts can also report symptoms precisely instead of giving a vague description, says NASA astronaut and former flight surgeon Mike Barratt.

[...] The best way NASA can think of to manage problems is to have as much expertise on the crew as possible. One of the ways that they manage risk is to say that every planetary mission must include a physician-level crew member on board. Another way is to look at the history of space exploration, as well as similarly remote environments such as submarines and Antarctica, to see which human health problems come up the most. A surprise one was urinary tract infections, which affect men in space far more often than on Earth. So NASA is building up its database to try to keep its astronauts safe.

Microgravity eats away our bones and muscles:

“On muscle and bone, you have de-loading effects which can be mitigated by extensive exercise,” says NASA’s Peter Norsk.

NASA is especially concerned with how a lack of gravity and increased space radiation could hurt explorers on the way to the moon or Mars. On Earth, we are protected from most forms of radiation due to the atmosphere; in space, explorers in low-Earth orbit still get a little less radiation than in deep space due to Earth’s magnetic field, which deflects some radiation from space. But on the way to Mars, that’s not the case.

Norsk said that doctors still don’t understand how radiation can affect astronaut bone and muscle. It’s hard to simulate deep-space radiation on Earth, and we only sent a handful of astronauts to the moon back in the 1960s and 1970s.

Environment; Space attacks our immune system:

One of the things that hurts astronauts in space is the loss of a regular “day” in space. The sun rises and sets 16 times in 24 hours aboard the ISS, because astronauts hurtle around the Earth once every 90 minutes. While crews do as much as possible to keep their bodies to a schedule – like eating at regular times and having firm sleep periods – it’s pretty difficult to fool the brain when light and dark keeps changing outside the window.

Right now, doctors are trying to better firm up the circadian cycle by improving sleep for astronauts, which means reducing noise, making their schedules less stressful in the evening so that they can wind down, and taking other measures.

“In-flight sleep is important,” says NASA immunologist Brian Crucian. “It can affect the immune system.”

  • $\begingroup$ Further answers are still very much welcome! $\endgroup$
    – uhoh
    Commented Sep 25, 2018 at 5:58

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