Is anything necessary? It's easy to define away the necessity of anything, even living. The point of manned space exploration is ultimately about colonization. The point is for people to go, to do, to live. And you can't get that with robots no matter how hard you try.
We can no doubt learn the secrets of the Universe through robots, and we very much should do so. But there is more to the Universe than just studying it. We should touch it. Play in it. Live in it.
Perhaps I should've re-worded my previous comment because I did not mean to suggest that we abandon manned missions forever or that we try to experience space vicariously through robots.
I'll elaborate. There is tremendous risk involved in sending people to space, I'm sure those who sign up for it understand and accept that, but it's a tragedy when it goes wrong given the caliber of people who end up dying. The overhead in designing for human needs (oxygen, water, food, waste facilities, etc) seems like a waste of time and engineering effort until we can better guarantee their safety. Of course I think the time will come when it becomes as safe and accessible as a trip on a 747, but I think an effort in purely autonomous systems that parallels the efforts being done on manned space technology should be considered to serve as a supplemental aid to further space research - a lot of which, I'm sure, would end up contributing to that dream of reaching the stars.
I think that's being overly and unnecessarily cautious. If we wait until there's no risk then we'll end up waiting far too long. There's always going to be some risk. There's a ton of risk just in getting out of the house and driving on the road. But there's risk in sitting on your ask at home too. Also, a great many astronauts are more than willing to take these risks. If you look at the Gemini program, for example, where astronauts knowingly strapped themselves in to a capsule on top of a modified ICBM which had up until that point around a 1/3 failure rate.
Personally I think that engineering even safer manned spaceflight systems is a good idea and a very worthy goal but I think if our choice was to explore the Solar System with a vehicle no safer than the Soyuz or to stay at home the choice has to be to explore, every time.
>There's a ton of risk just in getting out of the house and driving on the road. But there's risk in sitting on your ask at home too.
The risk factor involved in manned space missions versus a trip to the grocery store has got to be huge orders of magnitude in difference. This is an unfair, and frankly, useless comparison.
>if our choice was to explore the Solar System with a vehicle no safer than the Soyuz or to stay at home the choice has to be to explore, every time.
This is where I can't agree. You have to define "explore" - i.e. the particular objective of that flight on a case by case basis - and ask if it really warrants sending a human being up to do that job. Yes? Then by all means. Do it. No? Then find a safer alternative that accomplishes the same goal and that sheds the challenges of keeping a human being alive in a truly hostile and unforgiving environment. Also, I wouldn't consider sending an autonomous vehicle out to explore as "staying at home".
I get the emotional appeal... I just don't think it's rational for every case unless we really need a human's capabilities in space.
Whether it seems nice or not, one of the experiments being conducted by humans in space is the effects of being in space for a prolonged amount of time on human beings.
We can no doubt learn the secrets of the Universe through robots, and we very much should do so. But there is more to the Universe than just studying it. We should touch it. Play in it. Live in it.