How can Humans in their right mind think of sending manned space crafts out of our Solar System. Why is NASA spending Trillions of dollars on developement of space stations and space crafts?

If the vision is to target space tourism and commercial ventures within our Solar System, maybe it makes sense.

But if the Human species would like to find a new home, before we run out of options on our present home, we better think out of the box.

The Human body is too fragile for space travel. We have to find some other revolutionary way forward if we want to save the Human species from extinction.

How about NASA inviting suggestions and proposals for a practicable and feasable alterantive to space travel on the lines of X-prize. I am sure there are some Humans on Earth who are capable of thinking far ahead than how to overcome the problems of space travel within our Solar System.

Or we can make 3 or 4 billion and go there ourselves

I'm as impatient as you Al.

Good to get a reply……..
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What you wrote was my point. The mentality of us today. Build a gigantic ship, or an umbrella 50 km in diameter, or ion drives, or whatever…. That's my point. I used the word “practical”. In our lifetime.
By all means I am for space exploration -more than most, I'm sure- and we make due with what we have at the time. I'm just saying that speed is the key. We won't accomplish much until we solve it. And I'm not talking about folding space or going through worm holes or any other such things.
But hey, who am I? I'm a rebel. I still firmly believe that some day we will be able to build a machine that can propel us faster than 360 M m/s without traveling in time. It is really a shame we have slowed down so much that I'm going to miss it…
As for our (my) ancestors pulling up stakes and heading for the 'New World' two hundred years ago; I follow you. I may have never existed if they didn't have that adventurous 'spark' in them. I'm just getting impatient, that's all.

We can go to Mars faster than 6 months.

It just takes more Delta V.

Which means bigger rockets, more fuel, etc. etc. and then we have a 'Battlestar Galatica' type ship that costs so much that no one will pay for it.

The reason for 6 months is because its cost effective, using a near Hohmann transfer from Earth to Mars, we use far less delta V.

Lets get to Mars first and set up a small colony before we have to worry about shorter trip times, after all humans didn't wait for speedy transatlantic flights before traveling to North America.

We'd still be in the dark ages huddled together in dark box.

Its in our nature to explore and to do it ourselves.

The Academy spelled out knowledge gaps, for example, and was more than useful and certainly a scholarly and serious work.

Among their many conclusions is that we do not yet have sufficient shielding from Galactic Cosmic Rays, particularly from the heaviest and most energetic nucleons,

Lunar travel, the Board concluded also, fell well within the 3 percent probablity of REID (Radiation Exposure Induced Death) but all estimates of missions to Mars fell outside this minimum probability that stands as a proven standard for NASA safety protocols, particularly for what can be described as non-linear probabilities, basically a flip of the coin.

Sorry, Hoaxers, but your average trip through the Van Allen Belts is not a proven hazard and sufficient mitigation exists for LEO and short-term lunar distance flights, though obviously Solar Partical Events pose great risks.

And NASA's basic science into radiation is dependent on a Air Force facility that may soon close down.

Far from the Government Accounting Offices screed, MANAGING SPACE RADIATION RISK IN THE NEW ERA OF SPACE EXPLORATION, from the National Research Council of the National Academies, is available in pre-publication at their website.

Facinating reading for anyone wondering where to find their niche in the future of manned (and unmanned) exploration. Discover an effective method for sheilding, or, better, mitigating GCR exposure, heaviest at Solar Minima, like the one underway now. The world may beat a path to your door. Just remember there are all kinds of radiation, some more head-scratching than others.

Such technology would make life on Earth a higher probability, as well. The Solar Minimum underway at present (accompanied by an unusually strong solar wind) means GCRs are infalling at 50-60 percent higher a rate than at Solar Max.

More than radiation (though not to minimize it in the least) the constant threat to the human body is 6 months of weightlessness. We can shield ourselves from the solar flares that may or may not occur on a mission but astronauts will always suffer from the weightlessness problem.

As it stands now, astronauts and cosmonauts that return from 6 month stints on ISS are, for all intents and purposes, basket cases physically. Every effort to stave off the effects of weightlessness really doesn't ameliorate the debilitation they endure. What will happen when a basket-case astronaut lands on the surface of Mars, experiencing his/her first gravity in 6 months, and there's a life threatening issue that must be dealt with immediately? It's likely there would be a mission failure because the infirm astronaut is incapable of physical interaction rather than the insolubility of the threatening issue. More than anything else, I believe this is the potential showstopper for a mission to Mars.

That said, I don't think we're forever doomed in any attempt to get to the Red Planet. I think our propulsion technology needs to be upgraded and when we do that we'll go to Mars on a regular schedule not unlike our pioneering expeditions to the moon during Apollo.

Chemical rockets giving a Mars ship a huge kick at the outset of a mission and then freefalling on a ballistic trajectory is the problem. A mission to the moon taking 3 days is easy. Make it a 6 month voyage and we're into an entirely differerent technological area. I believe the solution lies in the development of an ion drive or a variant. The operative fact here being that the drive be sufficiently powerful to accelerate a mission-viable mass at 32 feet per second squared or 1 g.

I had the opportunity to speak to the Principle Investigator for the Dawn mission to Ceres and Vesta currently enroute to these minor planets. Dawn is using 3 ion drives that, admittedly, are very low power but their potential for the future is the fact that they run constantly and, though acceleration is very slow, it is indeed accelerating to its objective. I asked the PI if these engines could be scaled up and he assured me they could. I think an advanced ion drive, several generations removed from these drives and capable of accelerating a mission-viable mass at 1 g thrust will put the human race on Mars for the remainder of our existence. These drives will make us a spacefaring species.

Consider the mission scenario: leaving Earth orbit the engines are powered to 1 g acceleration. All occupants feel normal Earth weight and function as they would if they were, say, on a submarine. At the half way point, the vehicle is turned around and for the remainder of the flight, until orbital insertion around Mars, use the engines to decelerate. The occupants still experience a normal 1 g environment.

I have read speculative papers that say such a ship could be at Mars in 2-3 weeks. If these numbers are valid, the benefits are manifold. Gone are the tribulations of 6 months of weightlessness. The psychological effects of being cooped up in a 'tin can' are minimized. The long term exposure to the radiological environment of trans-Martian space is significantly reduced. And, as the engines get more powerful, the spacecraft habitat can become more protective by installing lead shielding. The efficiencies of these engines should reach a level where mass will be a minor consideration.

I believe that research and development money should be focused on these engines. I believe once these engines are fielded and operational we'll have a thriving Mars colony with supply and crew rotation ships arriving on a regular schedule similar to our outposts at Antarctica. I hope I live to see that day.

We need a lot more experience in Earth orbit first, we need to have a presence in space that is quite a bit more routinary than the one we have now, we need to perfect the techniques to build and repair in micro and low gravity, which means we may need a moon base before we go to Mars. AND we need to explore the planet a whole lot better. Why not build a whole flotilla of rovers similar to the highly successeful Spirit and Opportunity and set them to peek around the planet for quite a while longer? Why do it with people relatively soon, when the robots are able to do a lot of work for a fraction of the cost?

Whenever I hear of manned spaceflight beyond low Earth orbit, I get the shivers at the thought of the huge amount of breathtaking science that may get put in the drawer due to the sheer cost of sending people to the Moon or beyond.

'Cause yes, robots can also stir mankind's imagination. Hubble has been a continuous source of awe, and so has been Cassini and the various Mars robots. The same could have happened with Venus Express, if only its object of study showed us a prettier face and ESA had better PR skills. And I can't wait to hear from Dawn and the Pluto part of New Horizons mission. And even Rosetta, not to mention Messenger.

If a manned Mars mission implies cuts in robotic missions, and I really can't see how it can not imply, then I just don't want to see it. We'd be losing way too much in exchange for a bit of thrill and sense of adventure. I just don't think it pays.

100% opposed to manned (or monkey) space flight.

In answer to that one Ian, man has endured worst.
Zubrin probably said this also in one of his papers or books.

It took half a year to sail to Australia from Europe when Europeans where settling there, and in worst conditions than in a space craft, thats about the time it would take to get to Mars presently.

Also many people have survived wars without seeing home for years and not even spoke to loved ones and receiving nothing but terrible conditions as well as the enemy looking to kill you.

At least on the way to Mars they can comunicate with home, the apollo astronauts where never alone, even Michael Collins said he never felt 'alone' when he was in the command module by himself.

People are survivors, going to Mars is going to be easy on us compared to a lot of the stuff we have done before.

Cheers Ian

Ian

That is very interesting what you mention about the 1% radiation exposure. I am very dubious whether this is totally correct, I'll have to check it out though. I read the Case For Mars a while ago, so I'll have to hit the books

I'm 100% with you on your opinion that we should just get to Mars and stop worrying about it. My biggest fear is that we are going to sit on it, procrastinate, get bogged down in health and safety regulations, then the US government changes policy and it's another 40 years till we consider a manned moon mission again. We've been waiting too long, and our technology is more than capable to deal with these problems.

Putting the radiation risk to one side, I have more concern for the psychological problems facing us humans after many months in space.

Thanks for the discussion, you got me thinking!

Cheers, Ian

This radiation 'problem' is just more time wasting nonsense.

In terms of risk, anyone going there would gladly accept any risk, for example in everyday life, I accept the risk when I cross a street that a car may hit me.
But that does not stop me crossing the street, why should the risk of radiation stop us going to Mars?

Its about time mankind and their repective goverments 'grow a pair' and go to Mars.