All of the below is Copyright 1999 Adrian Hon

The history of a manned Mars mission

First, I'd better give you a bit of the background on the so-called 'official' studies conducted about a mission to Mars. As usual, the reasons behind the first intensive study was political.

George Bush, our favourite Cold War President of the United States, responsible for such space projects that have had varying degrees of success, like the Strategic Defensive Initiative, the Space Station Freedom and the Space Exploration Initiative.

The Strategic Defensive Initiative, as yet, does not work. The Space Station Freedom, now the International Space Station, is not finished and is massively over budget. Finally, the Space Exploration Initiative, well, that died a very long time ago. On second thoughts, maybe their success wasn't that varied after all.

Of these three projects, the Space Exploration Initiative had the most unassuming name, but was probably the most important. It involved sending humans to Mars. George's intent was likely to be that of JFK's, when he announced the Apollo Project to the Moon, and so garner a few more votes for the next election and earn his place in history.

So George asks NASA to produce a report on the feasibility and cost of a manned Mars mission. This is in 1989, ten years ago. Three months later, NASA gets back to him, and they say they've finally finished. George rubs his hands in glee, and invites them over to the White House. Tell me about this Mars mission, he says.

Well, it'll be difficult, says NASA. First, we'll need a pretty big orbital construction platform to make a spacecraft. That'll be the spacecraft going to Mars, right, says George. Well, no. Those spacecraft will go to the Moon, says NASA. George ponders this for a second, wondering whether it was the Moon or Mars he told NASA he wanted to go to. But NASA continues, saying that when the spacecraft gets to the Moon it'll make a lunar base. A lunar base? thinks George. I didn't ask for a lunar base. What're these guys smoking? NASA finishes by saying that at the lunar base, they'll make the spacecraft going to Mars.

Right. And how long will this take, asks George. Oh, about 20 years. Twenty years, thinks George. That's a long time, and anything could happen in 20 years. Hell, the Cold War might be over by then. But, who cares, I'll find out how much it costs.

Enough of the small talk, says George. How much? The NASA officials umm and err, and finally say, half a trillion dollars. Half a trillion dollars? cries George. You've got to be joking. The NASA officials have a little laugh, and say, yes, they were joking. No, the Mars mission would only cost 450 billion dollars.

George thanks them all profusely, and ushers them out of the White House. Shortly afterwards, the Space Exploration Initiative is mysteriously axed. And so, NASA lost one of their best chances of sending humans to Mars this century.

It's pretty obvious why this NASA projected at least 450 billion dollars over twenty years. In 1989, and still today, huge amounts of money would be required to lift up the materials for an orbiting construction platform, and lunar base, not to mention the research and development costs, and maintenance. In comparison, little money would be spent on the actual spacecraft going to Mars at all.

You might think that this 450 billion dollars is, if not feasible, at least realistic. Providing, that is, that a Mars mission would in fact require an orbiting construction platform, and a lunar base.

Does it? Well, let's first see what you really need to get to Mars. You need a spacecraft to take you there, you need a spacecraft to take you back, you need somewhere to stay on Mars, and you need fuel for both ways.

One solution for all of this is to build a huge Battlestar Galactica-like ship that contains everything you need for the entire journey. It's probably the most obvious solution. However, this Battlestar Galactica would weigh 1000 tonnes, and so, you would need a space station and lunar base to construct it.

But that's not the only solution. Instead of doing all of Buck Rogers stuff, to reduce cost, what you need to do is to find a way of reducing the amount of mass you lift into space. At the moment, it costs about several thousand dollars to put one kilogram into space. It's hard to put an exact number on it, with all the different rockets we have, but we know that cost will not drop below one thousand dollars per kilogram for some time.

Also, you have to reduce research and development costs. The Battlestar Galactica ship would use some advanced nuclear propulsion, which we haven't even tested yet.

Okay. First, we'll concentrate on research and development. We have perfectly good Atlas and Ariane rockets that can lift mass into space relatively cheaply. There is no need to develop new hardware, and if we did, we could just assemble a new rocket from off-the-shelf parts. So, at a stroke, you've slashed R&D costs.

However, there has to be a trade-off with this. A nuclear propulsion drive is probably the only practical way of getting a 1000 tonne spaceship to Mars. So we have to find a way to push all this mass to Mars.

What we do, is split it up, and use less. This makes things a lot cheaper. Think about it. If you load all your food, and fuel, and landers into one huge ship, you're going to need a lot of fuel. And you'll need more fuel, to move the extra fuel. If you split up the components, and aren't so worried about getting them to Mars quickly, you save a lot of money.

How do we do this? Surely we'd want everything to get to Mars, the fuel, and the landers, and the food, at the same time quickly, since we've got humans on the ship? No.

Here's the idea. Using one of our cheap rocket launchers, in year 1, we send an unmanned habitat to Mars. It takes roughly 8 months to get there, but it's in no hurry because it's unmanned. Because it uses what we call a low energy trajectory to Mars, it requires very little fuel, saving money. At the same time, an unmanned Mars Ascent vehicle and Earth return vehicle are sent, and they also take 8 months to get there. I'll talk more about those two later.

In year three, you send exactly the same things, all over again. A habitat, an Earth Return vehicle (ERV) and a Mars Ascent vehicle (MAV). But this time, you also send a four humans on a ship to Mars. That only takes 6 months to get there.

By now, the three you sent in year one have already got to Mars. The habitat is sitting happily on the Martian surface, not doing much at all. The Mars Ascent vehicle is sitting nearby, busily synthesising fuel from the Martian atmosphere from carbon dioxide and hydrogen to produce methane. Since it can make its own fuel on Mars, it doesn't have to take extra fuel with it. More money saved.

And the Earth Return vehicle is orbiting around Mars.

When the astronauts arrive, they land nearby the already fuelled up Mars Ascent vehicle, and habitat. In the extremely unlikely case that both are not working, the astronauts can hop in their rover and drive to the other habitat and Mars Ascent vehicle you sent with them, which, by the time they have to come home, will already be fuelled up.

So you have a good backup plan.

In year five, the astronauts get onto their Mars Ascent vehicle, which takes them up to Martian orbit. They rendezvous with the Earth Return vehicle, and start the journey home.

Also on year five, you have another MAV, ERV and habitat sent to Mars, along with some astronauts in their spacecraft.

This means you have a continuous stream of astronauts going to Mars every two years, along with backups. At the same time, you've also got a growing collection of Mars habitats left on the surface, which can be hooked up to produce a larger base.

This plan costs 50 billion dollars, one ninth of the original 1989 plan. The 50 billion would include all costs, and guarantee three human missions to Mars. It's called Mars Semi-Direct, and was produced by a scientist named Robert Zubrin, in conjunction with NASA.

Why Mars Semi-Direct? Because Zubrin, on his own, produced a plan called Mars Direct, which would have combined the Mars Ascent Vehicle and the Earth Return vehicle into one vehicle that could blast off from the Martian surface straight to Earth. This would have meant you would only need two unmanned vehicles launched every two years instead of three. NASA didn't like this because they weren't sure whether the fuel making facility on Mars, in situ resource utilisation, was up to making that much fuel, so they compromised.

It's estimated that the Mars Direct plan would cost even less, maybe 20 billion dollars, over twenty times less than the 1989 plan. Each subsequent human mission to Mars would cost 2 billion. In perspective, that's the cost of three space shuttle launches.

Why should we go? (one at a time, please)

Why should we go to Mars? It doesn't matter how little it costs, or how quickly it could happen, there is no point in going if there are no good reasons.

This is where the tentative co-operation between Mars exploration advocates falls down. Everyone has their own reasons for going to Mars, and often enough, they clash.

The most popular view is that we should go to colonise Mars and create some kind of utopia, free of crime and prejudice. Unsurprisingly, people are very lacking in details about how we would go about creating this utopia.

Most people agree with this view, in one way or another. But that doesn't mean they agree. Some say that we should terraform Mars - change its atmosphere so that we can live and breathe on the surface. It might take thousands of years, but it is technically possible. Others say that we should preserve Mars; what right do we have to destroy the planet? What happens if there is indigenous life?

Then there are the fence-sitters, who tell us we should wait and conduct scientific research on Mars before we start altering it. But how long should we wait for? How can we be sure that there isn't some life, somewhere, that we might kill if we terraformed the planet? How can we be sure that even by being on Mars, we might harm its possible life?

All this was bad enough, but at the Second Mars Society convention, the author of the Red Mars series of books, something of a Bible to Mars Society members, Kim Stanley Robinson voiced another new view. In contrast with his books, which depict humanity's exploitation, colonisation and terraformation of Mars into a habitable pseudo-utopia world, he said that we need to think of going to Mars as part of environmentalism. Nothing in outer space could replace the comfort and fertility of Earth. Those who think of a developing Mars as a refuge to which people can flee overpopulation and ecological degradation are escapists.

This is certainly true, in a way. We found out about global warming from the planet Venus first, which had a runaway greenhouse effect due to its carbon dioxide atmosphere.

The dream, at least of the Mars Society, and I suspect many, many other people, is that one day, humanity will colonise Mars, the Moon, the solar system, the stars and the galaxy, forming a grand United Federation of Planets, to borrow a term from Star Trek. You can't blame people for believing in this dream, and they all speak in terms of humanity's rise to the stars as being inevitable.

What do I think? I compromise. Mars has a wealth of possibilities, and unlimited potential. It holds a record of planet formation, of weather patterns, of extra-terrestrial life, geography and geology and asteroidal activity. It has minerals, metals and every element required by humans in excess. It has water, enough to have formed an entire ocean. It has space, enough for millions of humans, animals and plants. It could become a new home for humanity, a cutting-edge scientific outpost, a utopia or a dystopia. Mars is whatever we want it, and make it, to be.

Unfortunately for me, those words don't win over everyone. Perhaps, to save time, I'll pre-empt the question I'm always asked when I talk about Mars. Why should we go, when there is so much wrong with Earth? Shouldn't we concentrate on what we need here, before gallivanting off to other planets?

It was a hard question, and it took me a while to think of an answer that I liked.

People say that we should spend money on getting rid of the homeless, curing cancer, building more hospitals, and all the rest. I've always replied that any amount of money will not make these problems go away, and certainly not the relatively small amounts used to explore and colonise Mars. Yes, we shouldn't ignore the problems we have now, but it's just not practical and it's not possible for us to make sure that conditions are perfect at home before venturing outside."

People say that we could spend $20 billion on education, on feeding the poor, on wiping out crime, on improving healthcare. But would that make conditions any better in the long term?

The problems of the third world, the disease, wars, famine, global warming and terrorism are not caused by lack of money. They are caused by human 'nature'. I certainly don't want to say that we shouldn't do anything about them because, at heart, we are all scumbags (which we aren't. At least, most of us aren't). But we can only find the answer to these problems within ourselves, not within our wallets.

I believe that Mars has potential. There is a lot we can do with it, once we get there. It would be an awful shame if we never went, because we were too frightened of going outside and taking risks.

(15/8/99)