You do know that there’s this thing called Wikipedia, right, ralph?
Short answer for those too lazy to click: redesigns after the Challenger disaster reduced its cargo and passenger capacity; the end of the Cold War changed the political climate in Europe.
I’d be happy with an unmanned sample soil return mission.
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Or a no-return manned mission.
…With Justin Bieber on it.
For political purposes, there is no way the government is going to sponsor a one-way human trip. It just is not going to happen. Some private enterprise might be able to scrape together the cash and fund such an event, but NASA just isn’t going to do it.
A robotic soil sample return is one of the items on the Mars short list. With Mars missions circulating approximately every 2 years, this is one that is likely to come around soon.
Of course there has been 1 unmanned martian sample return - the Alan Hills meteorite. Not quite what you wanted.
It’s all in the marketing. A one-way mission to Mars is bad. Being the first colonists on a new world is good.
“When the Mayflower set sail, those aboard her knew they were making a voyage from which they would not return. Nor did they wish to leave their new world, instead choosing to stay forever”.
Like that. With swelling music and a flag blowing gently.
*You’re chosen/for this great mission
Because you’re hearty and strong/and make a lot of fuss
Especially around us/We like you better when you’re far away
Have you noticed?/you’re gong the wrong direction
We have, but that’s your problem/We planned it that way
We had to dispose of all of you so/we can spoil the final frontier
How dare you question our Star Wars plans/for the farce that they are? *
[INDENT][INDENT][INDENT][RIGHT]–Dead Kennedys, “One-Way Ticket To Pluto”[/RIGHT][/INDENT][/INDENT][/INDENT]
Stranger
Mars is not “the New World”. It does not have natives to exploit, animals to trap sell for fur, large deposits of readily available precious metals, or even sufficient nutrients to support agriculture even if you could cover and pressurize a crevase or valley. It gets less than 1/3rd of the incident sunlight than would be received an Earth orbit, and is subject to weeks-long dust storms which blot out almost all sunlight except at the top of Mons Olympus. It is a barren, oversized moon with just enough atmosphere to make landing a very tricky exercise, but not enough to extract oxygen or nitrogen from. There is no habitation on Mars without transporting nearly every single structure, nutrient, machine that would be required other than the very modest amount of surface water that is irregularly available at the polar regions.
There is no colonizing of Mars in any realistic sense of the word without near magical technology, and certainly not with anything like the existing state of the art in space habitation and propulsion.
Stranger
On the other hand, see Joe Haldeman’s sf novel Marsbound for what seems to me (before the aliens turn up) like a pretty realistic portrayal of what the first permanent human colony on Mars will probably be like in 50-some years.
Maybe we’ll find out Phobos really is hollow. 
Only in the same sense that ISS has been “permanently manned” since 2000. We can keep people alive and keep servicing it, but the crews are on rotation and nobody is a permanent colonist there. Unless you count Robonaut.
A Mars colony at this point would be more Earth-dependent than McMurdo Station in Antarctica is on resupply from the US. We certainly could plan a permanent colony, but it would be a financial commitment to dwarf Apollo and ISS combined, and probably throw in the war in Afghanistan and Iraq to boot. You can’t send them on their way with a few trivial supplies and hope they make it. They can’t fend for themselves after a little set up help.
Right now, the idea of being “the first permanent colonists on Mars” is no different from being “the first grave markers on Mars”. Soldiers going to Iraq had a longer life expectancy. People going into nursing homes have a longer life expectancy.
Mars can’t be tearraformed for centuries and centuries. But somebody is going to be the first person to live there, and somebody will be first to die there.
Bringing people back doesn’t seem likely. So permanent emigration is the next option.
I think that might be the same person.
Mars likely cannot be terraformed ever without beyond science fiction level technology, e.g. the ability to move the planet, saturated the soil with nitrates, et cetera.
If we cannot even expend the resources to return a crew from Mars, what possible reason would you have to believe that we could either send enough equipment and supplies to sustain a crew through the next forty-odd years of life or maintain a logistical chain to provide supplies? We can barely keep the ISS staffed and falling out of the sky for the next ten years or so before it is retired.
Stranger
Well, remember the pilgrims on the Mayflower were going to a place that had a breathable atmosphere and water.
In more SLS news, from NASASpaceFlight.com: Dual SLS launch campaign required for NASA’s Lunar return
August 21, 2013 by Chris Bergin
A return to the surface of the Moon would require two Space Launch System (SLS) rockets launching over half a year apart, with a four person crew being transported to the Lunar surface on a multi-billion dollar Lander for a seven day sortie mission. The overview, provided in the latest Concept Of Operations (CONOPS) document, all-but rules out the option based on cost estimates alone.
Stranger
And what a colossal waste of money that would be. There is no justification to send people to the moon again. We should wait until nuclear/plasma rockets are perfected, and then perhaps consider his. the return just doesn’t match the costs…or let the Chinese or Indians do it.
While I’m in agreement with this 100%, I do find it interesting that this is a much more ambitious mission profile: Landing four people instead of two–and being there for a week. Why the upsell? The article didn’t mention exactly why SLS was limited to every six months, but I guess part of it is we just don’t have an assembly line popping them out like soft drinks.
There’s a reason that for over half a century, people use “rocket science” to denote the pinnacle of scientific and engineering complexity. With a few possible exceptions like massive colliders, it probably still deserves the reputation.
In addition to the reliability and untestability issues mentioned above, the biggest issue with rocket science is the incredible interdisciplinary understanding required. You can’t just have a bunch of experts in different fields all representing their own turf. You also need a bunch of of experts in multiple fields to determine how they will interact in what would otherwise be unexpected ways.
Space programs are well outside the normal envelope for engineering, in terms of total energy requirements (both in terms of power and total energy), temperatures, pressures, radiation, and no doubt plenty of other environmental factors.
I bet guys like Stranger could go on for quite a while on what makes space flight more than just another engineering problem. Some day, sure, but today it’s still at the very edge of feasiblility.