The dexterity of the human body really should not be underestimated. A human being can perform relatively complex analysis in a lab precisely because s/he can move the samples around and whack the equipment a bit if it gets stuck. If you want a robot to do that without getting stuck - ever, then that becomes extremely expensive or you figure out a way to do it in a single chamber like the viking lander did, which is still way more expensive and starts ruling out more complicated forms of analysis. If some element of this mission breaks down, then the human being can also do in-field repairs - something that even the most sophisticated robots of our time can't do.

Beyond picking up rocks, the human can traverse the terrain more easily and s/he can climb up and down really steep slopes - even ones at a nearly 90˚ angle. Whether you'd want the human to do that due to safety concerns on an alien world is another matter, but the amount of terrain accessible to this being is far larger than most billion dollar robots.

Oh and the human being does all of this while being powered on tuna sandwiches. They might be expensive to send to Mars, but once they're there humans can explore a larger area than all rover missions combined in a single mission.

> Oh and the human being does all of this while being powered on tuna sandwiches.

and water and balanced nutrition and oxygen and a very narrow temperature operating range and a very short hibernate mode (cannot really go without water/food for an extended time) and have to sleep every day and sensitive to radiation and cannot operate in low pressure and need to defecate and urinate etc.

A drone/robot can be run on solar power. If there isn't enough energy it can go into hibernate mode for months. And you also have to take into account that a manned mission is planned for something like 2030. Robotics is such a rapidly evolving field that by then they will be so much more sophisticated than today.

Don't get me wrong. I think sending people to Mars will be awesome and inspiring. But I think it wouldn't be a rational decision.

Robots can't reproduce. They can't repair themselves. They can't even fix each other. One day in the distant future we'll build robots that can do those things, I'm certain of it, and then we can build planet-colonizing robot swarms. But even then, the most useful thing they will be able to do is prepare for the arrival of humans. Robots won't be ready to replace humans for the purposes of science and exploration until they're ready to replace us altogether, which is a long way off yet.

Sending 1 human to mars requires on the order of 20+ tons of equipment at a minimum, plus consumables. That's a lot of robots, so even if a human was 100 times better than the opportunity rover, sending rovers would still be a better bet. Worse there is a large risk they die before doing anything.

If anything Mars is a great opportunity for automation. It has no environment to destroy and with the right design it could end up exporting a constant stream of goods to humanity with zero environmental cost. Nuclear waste for example is a non issue. We could even try things like a space elevator on mars without risk of harming people on earth.

PS: For comparison the lunar lander weighed ~36,200 pounds and needed a lot less thrust to get into lunar orbit.

What goods would you expect to retrieve from Mars? Or do you mean that it would be a great place to locate industry that would create unacceptably high pollution on earth?

In theory, you send one von Neumann machine and in a few years it has a planets worth of manufacturing to send you anything you want. Sure, shipping would be energy intensive, and you only get ~59% as much solar energy to work with. However, the equivalent of a 2 million meter x 2 million meter solar farm could produce a lot of energy.

Assuming space elevators, you could replace the vast majority of earth manufacturing. Though, with a long lag time before arrival.

That's absolutely true, but I think the hesitancy about sending humans to Mars is that it is such a desert, and so the payoff will be quite limited to most people besides geologists. From the point of view of the general public, it's cool that its on another planet and we could do interesting science, but realistically it doesn't seem worth colonizing.

This is one reason that Europa excites the public imagination despite the hideous problems of distance and proximity to a gas giant - that moon appears to have a thick crust of ice covering a liquid ocean, and thus the prospect of life - possibly alien life, possibly a means of maintaining human life.

If we found evidence of life, even fairly primitive life, there would be plenty of money and public support to study it (though not without controversy). Rocks and canyons, not so much.

<The dexterity of the human body really should not be underestimated.

This is a great point. I haven't studied this topic much, but on the surface it seems to me investing these resources into robotics technology is more interesting. Why can't we have a robot that can do such things? I think we can.

I presume more complex experiments on site, that take time and gave a lot of steps and decisions to be taken. of course this also can be automated, and probably at lower cost overall minus potential casualties, but then there is irrational/emotional aspect to getting to a different planet, which is perceived as major milestone in mankind's aspirations.

mountaineers also go to potentially deadly situations voluntarily, just because the those peaks "are there". nobody gets satisfied enough from someone's else photos and says "nah, that's enough of an experience for me", albeit view doesn't offer much more. Neither they do send drones up there instead of them :) (btw that would be a nice use case for some remote high-adrenaline-vr gaming with androids!)

To think of the simplest and silliest example - you can get a shovel and dig as deep as realistically possible. Even our most advanced rovers dig hilariously shallow holes(due to technical limitations) and our science would be improved tenfold if we could simply roll over a couple rocks and punch a few holes through the ground.

Until we have AI (since remote control doesn't work in this case) and far, faaaar better robotics, humans are vastly superior to have on Mars. Well, if they're alive, anyway.

See also: You can probably do things a roomba can't.

Humans on mars would inspire future generations with dreams of space travel, which will make them more likely to support higher levels of NASA funding?

You mean like how landing on the moon did wonders for NASA's budget?

More like how the landing on the moon spawned SpaceX, Scaled Composites, etc. - It made people keep shooting for the moon.

Sadly, the more useful something is, the more it is underfunded.

>> Humans can do things on Mars that drones cannot

> Such as?

Growing potatoes?

The technology required to send people to Mars is not in itself worthless. The motivator is sending people to Mars.