Parallel thinking is good, until, e.g., inches and centimeters are used in parallel and the whole thing blows, this time to the tune of 10 trillion dollars instead of 100 million like the last time - just a couple of years ago.

The more details there are, the more can go wrong. The Apollo program had a multitude of test runs, including many of the maneuvering experiments from the Gemini program. They even had an almost test landing on the moon (Apollo 10). Landing on Mars would have to be done with a minimum of, or even no testing at all.

Myriads of details mean myriads of possible screw-ups.

We got to the moon and back more or less because we *really, really* wanted to. Without that collective national/international impetuous, even a possible Mars landing just might not take place.

Do we *have* to go to Mars? No.

The dreams of a necessity of human expansion are nonsense. One often hears of a necessity to terraform Mars and go there when we've screwed up everything here. Even an Earth screwed up by humans would still offer us about 98% of what we need to survive. If we don't understand the Earth's eco-system enough to solve our problems here on Earth, how are we supposed to create a new one? Even if we could find water and create a new atmosphere on Mars, we'd still only have about 10% of all the things we would need for real, unassisted survival. Create an atmoshpere on Mars? If the were possible, then why not just use the same technology to fix ours?

Will humans ever leave the Earth (as a collective body) and permanently inhabit 'the stars,' or even Mars for that matter? I honestly do not believe so. The human race is a product of the Earth and is here to stay. Anywhere else, it's a fish out of water.

Every time I hear the likes of Puttkamer blabbing away about colonizing Mars, I just shake my head and think "he's *got* to know better, is he just trying to raise money?" In the sixties, during the Apollo program, I saw lots of short films about us having permanent settlements on the moon by about 1995, with tens of thousands of inhabitants. Ahh yes. The talk about Mars reminds me of those films - often word for word. So I think "ahh yes."

[/minirant]

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Ach, mein Sinn, wo willst du endlich hin, wo soll ich mich erquicken? Bleib' ich hier, oder wünsch' ich mir Berg und Hügel auf den Rücken?
Bei der Welt ist gar kein Rat, und im Herzen steh'n die Schmerzen meiner Missetat, weil der Knecht den Herrn verleugnet hat.

I think we all see the problems with soft landing and return from mars. This thread has cleared the subject well.
Once again the issue is not how to do this, but how much it costs.
The how will be decided by logic and knowledge. Some of the 'how will we do this?'
will be solved with time and experiment.
The cost is the problem here. To justify the hideous expense is going to be difficult. That is not reason not to do it. We need to find another way to find the funding... and justify it.
I would vote for that. But this is looking a bit political is it not...?
Only the governments could fund such extravagance. I do wish that was not so...
So there it is, I wish we could just do these things and to hell with the budget.
Whats the option...? Robotics.

Landing a craft that can take off again with one or more humans on board after a long trip through space and a long stay on mars is hard. Just getting someone down there is comparable to what has already been done.

Hi , Well said.

Best regards, Dan

Right!

And if (apart from the difficult issue of ever getting there) living on Mars was easy, how come that on earth there is appearantly only very little people that live in the Antarctic or the deserts?

Must have *some* reason!

We discussed the interplanetary astronaut training aspect of this. The long and short is that fellow posters tended to slant toward spinning stations, although some thought of gradually changing the rotation so that it slowed down on the first leg, then sped up gradually for the return journey. This link for more.

Really? Why, then, does the worlds leading expert on landing on Mars - a mad directly responsible for the succesfull landing Pathfinder, Spirit, Opportunity and Phoenix - say that currently - we do not know how to land anything bigger than MSL on mars. 750kg - that's it.

We do not know how to land anything bigger. We don't have a clue.

You're wrong on this - very very wrong.

Doug

This is a serious exaggeration. There is a big difference between "solve a technological problem we know how to describe" and "don't have a clue". Of course we have a clue, we have a lot of clues. We know exactly what we need to do, and we know in principle how to do it: Fire some rockets and don't crash.

However, and this is really significant: The Mars Guy is talking about an entirely automated landing. Remember, the Apollo 11 lunar lander had a human pilot: Edwin Eugene "Buzz" Aldrin, Jr. There is a huge difference between automated landings, and human piloted landings. Any humaned mission to Mars will land under the control of a human pilot, and we have at least one or two clues about that. So the Mars Guy's comments are irrelevant to this question.

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The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell

One small technical note: actually Niel Armstrong was at the controls.

Tim,
The problem comes in that there is no way to assemble a spacecraft on the martian surface capable of carrying men and samples back to orbit for transfer to the mothership to return to LEO. I say "assemble" because you cannot land
a vehicle which will then return to orbit . 750KG .

Best regards, Dan

So, who here wants to be the one to tell "Battling" Buzz Aldrin that we can't do it? Because he says we can. Now, I might be wrong about this, but I think that Buzz probably knows a thing or two about spaceflight.

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Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Specifically, he says that his Mars lander works by 'Using aerobraking, a parachute and precision rocket braking, you touch down at the main base.'

It's my understanding that the numbers for those techniques simply do not add up for large masses, and this is a vehicle capable of carrying an entire crew back up to orbit.

The problems are identified. In order to safely return from a mars mission we need to lift a very heavy payload from earth. Land it and when the window for return opens lift of from mars for the return to Earth. There are issues. The problems are many. None of them will stop the attempt. It is do able... I have the confidence in the technical experts to solve all of these issues. We already know what is required. We already know the problems have solutions. The one and only issue that might postpone this mission is the same one that has prevented it from having already been done. The cost. Solve that issue and we are on our way. Mark.

Oops. That's what I thought, but I looked it up and found that Aldrin was listed with the crew as pilot. Sorry about that, Neil.

Don't make the mistake of thinking that 750 kg is some kind of magic number. Of course we certainly can land 750 kg, or any other mass we feel like landing. In case of either an automated or piloted landing, it is simply a matter of engineering design, and nothing that even approaches a fundamental problem. We could land a million tons if we felt like it, and then launch it again. Of course, this would be hugely expensive, very massive, very difficult, and not necessarily the best practical idea. But, then again, that's not the point. The point is that if we wanted to do it, we could.

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The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell

Actually - that's the insignificant part. The 'safe landing to avoid a boulder' part that a human on-site can play a part in fixing isn't the problem.

We don't know how to build a parachute larger than that for MSL. We've never flown alternatives such as inflateable balute designs. We've not flown anything analogous to the E and D part of the E, D and L. The L bit - yeah, a human helps there. It's the E and D part- that's the part that a pilot can't do, that a pilot doesn't understand. Sorry - Buzz's opinion at this stage is worth exactly zip compared to engineers who've actually landed things on Mars.

Go read the stuff at the JPL technical reports server about this. Go listen to Rob Manning's recent Von Karmen lecture about it.

I'm not saying these are insurmountable problems. They're not. Given time and money, we can fix these problems. However, at this stage, the challenge of landing a Man on Mars is as great, if not greater, than taking off again. That was the crux of my response to Ronald, who believes we should be sending people one way because landing's easy and taking off is hard.

A couple of thoughts here. One is that Buzz didn't get his Apollo gig because he was "merely" a good pilot, he got it because he was also a good engineer. He and the other Apollo astronauts did an awful lot of the engineering work on Apollo, so he's not just some fighter jockey saying, "Yeah, put a joystick on it and I can land it." He's done the work for figuring out how to land on another world. Second, and I realize that this is a bit of a stretch here, but I have a feeling that if Buzz were to call up anyone at NASA (or any other aerospace organization) and say, "I want to talk about what you know about ______." they'd happily give Buzz all the time in the world. I realize it sounds kind of crazy, but I'm thinking that an awful lot of people are at NASA (or wherever) today because of what Buzz did and would be happy to talk to one of their heroes.

Then there's the fact that Buzz has been retired for a good number of years and has had time to work on this stuff. The guys at NASA are probably really busy doing their day-to-day stuff so that they don't have much time to work out doing anything else. Its entirely possible, nay, probable, that Buzz has gone over all the technical reports generated by landing probes on Mars (since they would have used the lunar probe data for planning the Apollo missions) to develop his ideas. The NASA guys quite possibly, haven't been able to give a close examination to Buzz's work, simply because they don't have time, and its not really relevant to what they're doing right now. Were we to get serious about sending humans to Mars, they'd no doubt give it a good going over.

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Oh, and now that I think about it, Neil Armstrong, shortly after returning to the Moon stated that we had the technology to send humans to Mars then. Neil, obviously wasn't trying to imply that they could just point the next Apollo rocket towards Mars instead of the Moon, but that we had the technological ability to accomplish the task. (This is discussed in First Man, the official biography of Neil.)

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

Well.......we "can" send a man to the moon. But......"Landing him" and then getting him back is....well......a bit dificult.......see. Little bit there.

I know people are concerned about obesity amoung Americans, but their average male weight is still only 89 kilos.

We are all explorers and Earth is merely our vessel from which we have barely peeked out from. We shouldn't be asking ourselves the cost of acting upon our dreams and ambitions to explore the universe but the greater cost of not acting upon those.

We should go to mars because its there.

Hi Ronald Brak: Are pre-teen males (typically 10 to 60 kilos) averaged in to get 89 kilos? Neil

Sir, We are all stewards of this big blue marble that is our only home. It is so much more than a mere vessel. Our technology has given us views of the heavens and most distant galaxies. If we send our robots to distant places
it will be sufficient and we will be satisfied.
And smart people "always" ask about the cost. We have many pressing needs. All will be considered in good time.

Care to give us a reference or two for those? I managed to find a link on the JPL site to 'JPL Technical Reports' but it appears dead.

To those who think landing people on Mars and bringing them back safely is a relatively straight-forward process, I recommend they read about the engineering challenges of Mars Sample Return for unmanned vehicles. It's a huge technological challenge that NASA and ESA hope to accomplish by 2020.

Link 1
Link 2

There are some things that are pretty easy to predict but actually implementing them will be very difficult.

1. They need to fly humans from Earth orbit to Mars orbit. While it's possible to go straight for a landing like they've done with the last few unmanned landers, inserting into orbit has several operational advantages. These include the ability to use multiple vehicles instead of one larger one, the ability to leave the vehicle necessary for the return trip to Earth in orbit instead of having to land and subsequently launch it, and the ability to wait out a potential storm on Mars if necessary. Aerobraking can greatly reduce the amount of propellant needed to circularize the orbit at the expense of time.

2. You need to land the crew safely on the surface. This is difficult enough with unmanned vehicles but the challenges are harder with a much larger manned vehicle. You'll also want to eliminate as many failure modes as possible. For example, using parachutes to slow the vehicle has certain advantages but building them large and reliable enough is difficult (just look at the difficulties they had when testing the Mars rover parachute system in wind tunnels). You might want to bite the bullet and do away with the parachutes and go straight to rockets for slowing the vehicle after reentry.

3. The crew will need suitable living quarters while on the surface along with other equipment such as rovers. Do you land everything in one piece (making it much larger and more difficult to land) or do you use multiple landings? Multiple landings increase risk in some ways but have other advantages.

4. Launching from the martian surface and returning to orbit is something no one has ever attempted. If you left the Earth-trip return vehicle in orbit, the ascent stage can be pretty small. However, it still has to be big enough to carry the crew and their samples. If you can generate the fuel using in-situ resources, the size of the lander is greatly reduced. However, that also introduces another failure mode.

Hi, Well said and well observed.
And returning to mars orbit velocity will be magnitudes faster than anything we experienced in lunar operations. This is an extraordinary task which many do not percieve. It is called a 'gravity well ' and this one is really something.


Best regards, Dan

I don't know. I just googled it. I assume it is the average for US males 18 and above.

Ronald and niel:... I think you might have miss-understood some thing about the weight of the lander. Its not Kg., of the crew that are at issue. Weight of any lander on mars is critical to calculate breaking velocity down to a safe controlled landing. Nothing about landing on mars is simple. As has been well covered by others here.