Are Manned Missions Really Necessary?

[shynung]

Just like the title says.

Or, to clarify:

Do you agree with the statement 'Manned missions produce more scientific discoveries than unmanned missions of the same objectives, enough to make additional complexities associated with manned missions worthwhile'? Why or Why not?

[Tiberion]

Like with most things in the scientific world, its not that simple.

It depends on the objectives of the mission. "More" science isn't usually the goal of a mission as much as "the science we set out to get"

There are things that the astronauts did on the moon in 1969 that Curiosity cannot do on Mars 45 years later. There are things Curiosity can do on Mars today that would be risk or cost prohibitive for a man to do today.

If we were to send a man to Mars today, he would be able to do things in real time and see it with his own eyes, and he would also likely have some equipment with him to "boost his science output" in KSP terms. Since we also aim to bring our people back from those missions, they'd also return with a small amount of things to study in much greater depth. But Curiosity has done many things which would not be done by a manned landing (like travel many kilometers and examine a wider array of things)

Of course, unmanned capabilities will continue to grow (like sample-return) and as our own technology evolves we can explore farther and longer, but given our current tech, both are invaluable. And that isn't even considering unmanned probes that explore the solar system and beyond.

So they answer you poll really needs is: The question is incorrect because they rarely have the same objective.

[shynung]

The question is incorrect because they rarely have the same objective.

That may be true; the Curiosity rover was designed to do a list of specific science objectives, not the other way around. Likely, manned Mars missions would also be planned out similarly.

Though I'm focusing more on cost here. Specifically, whether unmanned probes are more cost-effective to deploy than astronauts for a specific mission (i.e. explore Martian surface), taking into account the cumulative science output produced by either mission in comparison to their respective total mission costs.

Though, I acknowledge that the balance here could be very different for different situations; manned missions to LEO aren't very uncommon anymore, for instance.

[Jouni]

Though I'm focusing more on cost here. Specifically, whether unmanned probes are more cost-effective to deploy than astronauts for a specific mission (i.e. explore Martian surface), taking into account the cumulative science output produced by either mission in comparison to their respective total mission costs.

That's something you may be able to estimate a few decades after the mission has been completed. Science doesn't produce predictable results that are easy for administrators to measure.

[Tiberion]

"explore Martian surface" isn't a specific mission, and there is no way to quantify the "cumulative science output" of two different missions anyway. (Jouni is right, it would be much easier to figure after the fact)

Curiosity is almost 2 years old now. A 2 year (planetside) manned mission to Mars would be extremely expensive simply because of the amount of supplies needed (as well as probably deadly with current tech due to radiation) so of course a Rover is more cost effective for what Curiosity is doing.

But for a 3 month landing mission where the astronaut takes samples and performs experiments (more complex than what the instruments of Curiosity are capable of) then creating robotics that could handle the tasks might be impossible at this point, and certainly time consuming and costly, so a human will have much more success.

But you'd use neither Curiosity or a human cartographer to map Mars in detail, an orbiter does the job much better.

You set a goal and then you choose the right tool for the job. Cost is one factor in making that choice.

For the things that rovers can do, they're going to be cheaper than a man most of the time, though there can be exceptions where the number of man-hours or technology needed to create your rover might exceed what it could cost to send a man, especially if we're not having to figure in the cost of a launcher for either one (which is of course not the case at all currently.)

Edited May 17, 2014 by Tiberion

[Seret]

There's no question unmanned missions generate a greater return of science output for the investment of resources. The fact we haven't sent any manned exploration missions for decades should be the first clue. It's not even a topic of discussion IMO, unmanned is the default choice. The analysis would have been done over and over, and we've never selected manned for any of our planetary exploration.

Essentially it's a technology problem. If we sorted out cost to orbit, long distance propulsion and closed loop life support then that might swing the balance a bit more towards manned, but right now it's just not practical.

Edited May 17, 2014 by Seret

[Tiberion]

Well firstly, it's not limited to exploration missions. There have been constant manned missions taking place since the space age began, and an unbroken streak of man in space since the ISS was launched. They aren't necessarily "exploring" space in the traditional sense, but they are nonetheless doing a lot of science.

Secondly, cost is one of the factors in the other exploration missions, but it's also just smart to do as much of the initial work unmanned as possible. Not only is it cheaper, but the manned missions will know so much more when they arrive, and will be able to directly do the important things that an actual living being should do there, like play golf and jump around. And you know, the serious science things too, if they have time.

So its not a matter of unmanned having superseded manned missions, as much as they have opened up a wide array of missions that men probably could not or would not do. So I wholly reject the notion floated in the topic that manned missions are not necessary. And it most certainly *is* a topic of discussion, because we're doing it right this moment.

[Rainbowtrout]

Does a robot planting a flag on a distant body give you the same amount of awe as flesh and blood doing the same thing? It seems more rewarding, more of a triumph when a person collects the necessary science/samples/knowledge. It is nature to explore, and maybe it's nature to want to go there yourself.

[bsalis]

At this stage unmanned is more cost effective, since it's the only real practical way with current technology.

Humans can bring a lot to the table, not just in terms of hands-on science, but in monitoring and fixing systems and more. However the additional cost is orders of magnitude... then there's the human factors, and risks. Imagine a manned Cassini–Huygens mission?! Billions in cost and possibly ending in tragedy.

Also there is more than science to space exploration too. The objective of the Apollo moon missions was "landing a man on the moon and returning him safely to the earth". Though, smartly, NASA decided that while they were there that they should collect some rocks and do some SCIENCE.

[Moar Boosters]

I think there's probably a limit to what we can learn about a place just through unmanned exploration.

Due to the time delay, the methods for exploration and reconnaissance are very inefficient. It performs a series of maneuvers, takes photos then this is all beamed back and analysed hours later. Some things are deemed interesting enough to go back to, some aren't.

These methods are going to miss so much compared to a trained geologist doing an EVA with a rock hammer. There are already whole websites full of people drawing red circles on curiosity photos questioning what they're seeing. I think we can learn a lot about places through unmanned exploration, but unless we can program robots with advanced AI or develop some sort of delay-free quantum communication device, if we want to learn in greater detail at some point we're going to have to send humans.

This probably applies even more-so to more dynamic places. If we were exploring a planet with an active water cycle, active volcanism or even advanced life...... operating robots with a massive time delay isn't going to cut it. You would need to be able to make decisions in real time to negotiate the hazards.

[YNM]

Due to the time delay, the methods for exploration and reconnaissance are very inefficient. It performs a series of maneuvers, takes photos then this is all beamed back and analysed hours later. Some things are deemed interesting enough to go back to, some aren't.

These methods are going to miss so much compared to a trained geologist doing an EVA with a rock hammer. There are already whole websites full of people drawing red circles on curiosity photos questioning what they're seeing. I think we can learn a lot about places through unmanned exploration, but unless we can program robots with advanced AI or develop some sort of delay-free quantum communication device, if we want to learn in greater detail at some point we're going to have to send humans.

The delay is due to speed of light (speed of EM radiation), not because anything else. Even if you had sent a human to Mars, communicating with them will have a delay of minutes to hours. You can either send a human with all the bulky life support, or send a pretty sophisticated thing (that'd be bulky too, I think) that can do the same. Maybe the things they lack are a deep enough drill, and even then, human eye can't do spectrometer.

If we were exploring a planet ... with active volcanism or even advanced life

Nah, if humans were present there, it'll be more danger that the result is dead humans, not dead computers. The thinking in outer space isn't to think the best that can happen or a middle thing (not good nor bad), but the worst could happen.

But from what we have done, I can conclude :

1. Manned mission : Humans can be there and IS / HAVE BEEN there ! XXX country wins ! - cost-extensive through

2. Unmanned mission : "Oh, I can see what they're without the need to go there ! Look, I didn't notice back then there's a hex..." - cheap cost and no endangered soul

[koshelenkovv]

Depends of mission.

Researching the rings of Saturn? Of course, unmanned mission.

Studying how to live on the Moon? Of course, manned one!

I think, for EO and Moon manned missions frequently will be more effective than unmanned ones (again, depends of what is studied)

For far space we really have no alternative to unmanned - flying to Neptune will take 15 years, it's crazy to send people. Even ion engines or VASIMRs will not make it faster than in a year.

Edited May 17, 2014 by koshelenkovv

[cantab]

For missions beyond Earth orbit where the science objective is not to study how humans ourselves respond to the environment, unmanned missions beat manned ones hands down in terms of cost-effectiveness. However, a manned mission will be far better in terms of time-effectiveness. The Mars rovers have done amazing things, but they are literally slower than a snail. (About ten times slower for Opportunity).

[SargeRho]

I don't think Robots can tell us how our bodies behave in space, or secure our species' continued survival well into the future. So "Strongly Agree".

[Tex]

Officially, my response is:

We need manned missions to better study how space interacts with and affects the human body. This planet won't be big enough for us for much longer, and we will inevitably need to inhabit a new planet in addition. Is it not better to study early on, so you have as much time for development as possible? As our knowledge grows, so to does our capability to live and work in space, discovering things mankind has never been able to do before. Thanks to the ISS and similar space stations, we know more about the universe than we ever could have alone. All the work is too precise for unmanned satellites and robots, so yes, manned missions are absolutely neccesary.

My unofficial response:

C'mon, how badass would it be to get to go to space?! There's no better view than from up there, and there's microgravity! Of course we need people up there!

[deadshot462]

Yes we do. A human can do more science in a day than a rover could do in a month. This is a quote from some of the JPL science team members behind Curiosity.

[Simon Ross]

In a word....Yes

At the moment, we are still in a phase where sending robots is far safer and cost effective then sending a man. Eventually we will hit a glass ceiling on what can be learnt with machines, but it's what they learn that will decide if it is worth sending a man at all.

[Alchemist]

Sometimes, people say that sending a man gives more flexibility on performing complex tasks. But a well crafted robot also could do all of it for much less total payload (and the reason the current robots aren't with human arm-grade manipulators and other such things is only that it's much cheaper and more efficient and reliable to stick a bunch of separate devices that don't require such fine tech).

What humans are really good at is making complex decisions while taking into account even unpredicted factors even if there's no connection with mission control or no time to explain the situation (just note the training for ISS missions and other Russian manned missions). But that becomes really useful for large scale long-term missions: if there's a reason to have a base/station - that's where a manned mission comes useful.

"Get there - take measurements - collect samples - get back" can always be done with robots. A long term wide profile scientific base can't (or gets to the point it becomes more expensive).

Why N1-L3 was relatively easily abandoned? Except for being a manned mission (not much of accomplishment after the success of Apollo) it wouldn't give much more that could be accomplished by the probes. Most engineers proposed keeping the rocket, but using it for lunar bases and other large-scale projects (and later these projects were adapted for Energia as well). It's a real pity neither side of the space race decided to go further and make the base.

I'm for manned space exploration, but (what is necessary in the modern world anyway) we need something more than "prestige first" behind such a mission. Something, that really requires human presence...

[peadar1987]

Yes we do. A human can do more science in a day than a rover could do in a month. This is a quote from some of the JPL science team members behind Curiosity.

But Curiosity has been on the Martian surface for 21 months now, and at a significantly lower cost than getting a human to Mars and keeping them alive on the surface for 21 days. Given a long enough time period, I'd say we could probably do 9 out of 10 things in space with a robot instead of a human.

That said, in my opinion, that tenth thing is absolutely worthwhile, and at some point we're going to have to send someone to Mars, and it will be awesome!

[Albert VDS]

So the general consensus seems to be that unmanned surface ecploration is cheaper. I would say it's the opposite. Just look at what the main goal is for the exploration of Mars. It's looking for past or present life. Now there have been 5 surface missions in the past 22 years. Take a look at Curiosity and how long it takes to reach places and to use it's instruments, let alone to reach Mount Sharp. A human team could do the 10km drive in a day and a other day to study the collected samples. If it's a Mars Direct mission, 1.5 year stay on Mars, then all the unmanned missions combined pale in comparison.

[Motokid600]

I don't think we need to send humans further then Mars/Venus in this century. Anything further needs some sort of cryogenic sleep system.

[Albert VDS]

No, not really, just faster travel.

[R0cketC0der]

We don't use hohman transfers for anything beyond Mars/Venus anyway - usually we use pretty complicated trajectories with lots of gravity assists to save dV and time.

[G'th]

Absolutely. Exploration, of space or otherwise, has never really been about what was cost effective, because it will almost always inevitably pay off.

That being said, given our level of technology, for certain goals it would be better to send robots. But this is more because you'd spend more time and resources on setting up a manned variant of mission X where an unmanned variant would require a fraction of the time and resources. We shouldn't say no to a manned mission just because it won't shower us in SCIENCE!, but we also shouldn't insist on a manned mission if its going to turn into a time and resource sink before it can ever get off the ground.

[Seret]

Depends of mission.

Researching the rings of Saturn? Of course, unmanned mission.

Studying how to live on the Moon? Of course, manned one!

Indeed. The main role that humans in space can serve is learning how to put humans in space. The robots have got the long-range and long-duration exploration covered, but if we're ever going to get a foothold outside Earth then we need people up there doing the research. Exploration isn't something humans are well-optimised for, the machines have us beat in terms of endurance, support requirements, and tolerance of the conditions likely to be faced.