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It seems like much could be learned in this way but it seems like only orbital missions have had non-human life onboard.

I could actually see NASA decide not to send a mouse and certainly not a dog/cat/monkey to Mars because of bad PR.

Am I wrong? Has it happened or been contemplated or is it too expensive to create a system that had a reasonable shot of keeping a mammal alive all the way to Mars? Got to figure this would be the first step before sending humans. Imagine bringing such an animal back to Earth, maybe even a breeding pair -- those would be two valuable mice and selling their offspring might be a significant revenue stream.

I see that Musk contemplated this: https://www.bloomberg.com/graphics/2015-elon-musk-spacex/ but NASA has sent more than one craft to Mars since the 1970s.

It seems like while maybe an orbital mission would be enough to test low gravity and radiation, a life-support system that worked all the way to Mars, even for a mouse, would be huge.

BrendanLuke15
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releseabe
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    NB: NASA is not the only space agency. – gerrit Apr 13 '22 at 07:47
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    Interestingly, NASA didn't send any animal to the Moon before sending humans there. – Pere Apr 13 '22 at 16:09
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    Not mentioned in any of the answers or comments yet, but an animal can't consent to the risks of spaceflight. If you read about Laika (https://www.smithsonianmag.com/smithsonian-institution/sad-story-laika-space-dog-and-her-one-way-trip-orbit-1-180968728/) it's heartbreaking. And yes, I know other animals were launched and recovered with no long term ill effects. That said, going to Mars and back is way riskier for the non-consenting animal than the (sub)orbital flights in the 1950s and 60s. – paulmrest Apr 13 '22 at 18:10
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    In addition to @ikreases's very good answers, I'll add PR.
    Can you imagine the exploitative press?
    "NASA sends dog to die on Mars"
     – dlchambers Apr 13 '22 at 17:56
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    It should be noted that the Soviet dogs and NASA chimps were sent up at a time when we didn't even know if space was survivable. No Earth creature had ever been sent into space before. Those questions have been answered. At this point, there isn't much that can be learned by sending an animal to Mars that can't be simulated on the ISS. I don't see there being a market for Mars mice big enough to make up for the billions it would cost to send a pair of mice there and back. – Seth R Apr 13 '22 at 18:44
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    @paulmrest animals are often used for research. While some activists heavily protest animal testing in the beauty industry, there is much less outcry in case of crucial medical research. BTW feeder mice are fed to carnivore pets without the mouse's consent. Yet, humans in large groups often don't act rationally, so it might happen that there could be a massive backlash for two mice sent into space "against their consent", while millions of mice are killed on a daily basis in research, as pet food, and due to pest control, which no one will care much about. – vsz Apr 14 '22 at 06:20

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Mice probably are too short-lived, you want something larger (unless you are building a generation ship!)

Domestic mice have a lifespan of up to about 30 months. This is not very long for Mars missions that are normally well over a year at least. Additionally, I do not think that reliable gestation and parturition of mammals has been demonstrated in space.

Landing on Mars with an animal and bringing it back alive isn't necessarily much easier than with a human (and in some ways could be much harder)

At the very basic level of feasibility of orbital transfers, the situation is very similar to the sample return problem. Sample return from Mars still hasn't been done or truly committed to, even for sub-gram samples, because, while a rocket to launch from Mars and transfer to Earth doesn't require as much delta-V or as much acceleration as a rocket to launch from Earth and go to Mars (putting it in the readily possible category rather than being marginally possible with extremely flimsy multi-stage vehicles), it still takes a pretty substantial rocket to launch from the surface of Mars -- and that rocket (even if unfueled and using ISRU to procure propellant) must be landed softly on Mars. At small animal scale, it's likely that the various "minimum gauge" concerns of practical aerospace hardware might be the limiting factor on how small this mission can be, rather than the actual payload.

However, a small mammal, just like a human, needs to be fed (at least 70 kg/year for a small dog), to have its waste disposed of, to have oxygen supplied and CO2 removed, to be shielded against radiation, and probably to be supplied with space and stimulation so that isolation and crampedness does not lead to stress and cabin-fever that quite possibly causes death by malaise or self-destruction. This means mass.

For an animal, there are significant additional issues: A number of tasks, critically feeding and removal of waste, have to be automated, which means additional weight and moving parts and risk of unreliability, in contrast to astronauts who can do them manually or with simple tools that don't need 100% automatic, flawless operation.

There isn't much you can learn in orbit that you can't learn in LEO.

If your goal is to find out how long-term partial gravity affects animals (a critical thing which we do not, indeed, know, and which is hard to learn on Earth), it would probably make more sense to run an experiment in LEO with a space station centrifuge, tumbling-pigeon or tether-based satellite. You will still have many of the requirements, but you don't have to land and take off, and the delta-V requirements (and therefore how much payload you get for the rocket) are vastly improved. You may be able to have astronauts tend them, and the mission length can be adjustable rather than both fixed and very long. Radiation shielding (mass) is also not as much of a problem in LEO.

If your goal is to evaluate the various stresses involved in a Mars mission, the thing to do is probably to make a battery of experiments to analyze them individually on the ground or in LEO, combining with things that we know already, rather than actually doing the Mars mission.

leftaroundabout
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ikrase
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  • are you saying that a manned mars mission will be attempted without a prior mission with, say, a small colony of animals? i am frankly horrified that any creature that can feel pain, physical and/or psychological, might be sent, but i can't imagine not doing so before sending humans. – releseabe Apr 13 '22 at 06:47
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    There's no scientific or technical benefit in sending a non-human animal to Mars @releseabe. – GdD Apr 13 '22 at 08:16
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    @releseabe if it was a case of just putting them in a can and sending them you would probably be right, but all you would learn from sending an animal on a 18 month mission is what they look like as they die horribly from their own waste. It is not that sending a test animal is not a good idea, it is that sending a test animal will be impossible long after a human flight is achievable. – GremlinWranger Apr 13 '22 at 08:34
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    @releseabe Humans can improvise and fix issues as they go. Animals can't. Anything that goes even a tiny bit not according to plan means the animal dies and the whole mission is lost. Can we reliably lock a mouse (dog,monkey) up in a box and leave it there for a year with fully automated care? If not, there's no point sending the same experiment to space. Note that nobody had sent a dog for a walk on the Moon before humans went there, Mars is much harder yet. – TooTea Apr 13 '22 at 09:04
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    We should not forget that apart from the issues described above that getting to Mars, landing on Mars and then returning to Earth is extremely difficult and has not yet been achieved even with soil samples. – Slarty Apr 13 '22 at 10:18
  • Let's do the soil sample thing by all means -- that would make "Moon Rocks" look pretty prosaic. That also would seem to be a minimal milestone before sending brave humans beyond Luna's orbit. Did Musk say a mission by 2022?? Wow, I think he is going to miss that date. – releseabe Apr 13 '22 at 11:36
  • @GdD: It is beyond my ability to believe that a human will be sent a mission before an animal is -- plenty of benefit, that is crazy what you are saying. This would be a huge "smoke test.." – releseabe Apr 13 '22 at 11:39
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    @releseabe I am not sure why you have this opinion. The US didn't send animals to the moon before people. – Organic Marble Apr 13 '22 at 11:48
  • @OrganicMarble: No, but the many animals the USSR and USA sent into space prior to this approximated the lunar mission, I think. Anyway, my extremely humble but strong opinion is that sending a few humans on this lonely and dangerous journey must be proceeded by sending animals. – releseabe Apr 13 '22 at 12:12
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    @releseabe, if you are unwilling to listen to the answers there's no point in asking the question. – GdD Apr 13 '22 at 12:31
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    @releseabe - remember that many highly experienced and qualified people do not think there is any value to be gained from sending an animal. If they did, it would be in plan. So, while your opinion is fine - it's not worth valuing it when skilled and experienced folks have a different one. – Rory Alsop Apr 13 '22 at 13:12
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    Elon Musk apparently considered this -- maybe he was uninformed at the time he considered it. – releseabe Apr 13 '22 at 14:26
  • @GdD: I am listening, i am not yet swayed. – releseabe Apr 13 '22 at 14:27
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    @releseabe What concrete benefit do you expect to get from sending specifically an animal specifically to Mars? Vs. things that can already be figured out more easily some other way. – user3067860 Apr 13 '22 at 14:53
  • @user3067860: it is the most realistic test prior to sending humans. we have no certain idea what effects on life might be encountered so far from Earth for so long. It is test of the effects of space and the way the life support systems work. We have a general idea of how radiation might effect even shielded CNS -- if the mice suffer mentally to the point that we can conclude a human would no longer be able to function, that is pretty significant, isn't it? – releseabe Apr 13 '22 at 15:09
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    @releseabe: Elon Musk says a lot of things. Some of them even make sense, some of the time. – Kevin Apr 13 '22 at 15:10
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    @releseabe You don't actually have to go to Mars for any of that, though. You could get all of that just as well in a higher Earth orbit and stay for however long you want--including getting home easier if you need to on short notice. – user3067860 Apr 13 '22 at 15:41
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    @releseabe Space is just 100 miles away - there is really no need to travel tens of millions of miles to study something that can be accomplished in our own "backyard". This is like suggesting one must travel to Antarctica to study how water freezes. – Nuclear Hoagie Apr 13 '22 at 15:59
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    @releseabe the many animals the USSR and USA sent into space prior to this approximated the lunar mission, I think Not really. Their purpose was to study the orbital environment before sending humans there. Once you have that (and we do), everything else requires a local human intelligence to gain anything more. So while the mission is in fact hazardous, there's no point whatsoever in sending animals without also sending humans to look after them, which completely defeats the purpose of sending them first. All of the expense to send them, for nothing gained that we didn't already know. – AaronD Apr 13 '22 at 20:18
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We do not want to contaminate Mars.

It's unlikely, but not completely impossible, that we are going to find life, or traces of previous life, on Mars. For this reason, anything that goes to Mars gets carefully disinfected.

You can't just send a mammal to Mars. If you send a mammal, you also send lots of microbes, especially in the mammal's digestive tract. These microbes are unlikely to survive outside an animal, but many microbes survive surprisingly well under the harshest conditions.

Microbes from Earth might wipe out an existing life form. They might reproduce for a while and leave traces which, later, could give us the impression that there was, at one time, life on Mars.

Even if both of these scenarios are unlikely, they're not unlikely enough to be impossible. The very small scientific gain we could get is not worth that risk.

Guntram Blohm
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    I don't imagine that the OP contemplated the animal leaving the ship when they got there. – Barmar Apr 13 '22 at 14:12
  • but the ship could crash. as it could with humans and then also contamination. with animals, they could be sealed in a container that would resist opening in a crash while humans u could not do this. – releseabe Apr 13 '22 at 14:25
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    As we are planning to send humans this argument does not pan out. – GdD Apr 13 '22 at 14:28
  • @releseabe Such a container would add additional weight and complexity to the mission. – called2voyage Apr 13 '22 at 15:29
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    I'm just waiting for a different, previously unknown rich eccentric (no, I don't know who it would be) to get fed up with the whole non-contamination thing (beliefs aside, from any perspective), and use their own resources to shoot a can of spam at it. – AaronD Apr 13 '22 at 20:23
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There is simply no point.

Animals were sent in orbit back in 1950s because the risks were pretty much unknown and we had to find a way to send humans.

And, sending humans was important mainly because the computers of the era were not capable enough for the tasks envisioned.

Producing heroes when no handy world war was available anymore was an added bonus, but not the main point.

In 2022, after decades of continuous presence of humans in orbit and few landings on the Moon, we pretty much know how to live in space and it is not a big deal.

Well, it still is a big deal, but in terms of expenses and not in terms of number of unknowns.

Going to Mars is pretty much an engineering and financial task, not a scientific one.

If we ever get ready to colonize Mars, we will be going the way we always did - with the families, cattle, guns, agricultural hardware, wifi routers and holy books.

fraxinus
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