“We are much closer today to being able to send humans to Mars than we were to being able to send men to the moon in 1961, and we were there eight years later. Given the will, we could have humans on Mars within a decade.” -Robert Zubrin

Of all the planets in the Solar System beyond our own, none has captured our imagination quite like Mars has.

From science-fiction fans to scientists and everyone in between, our understanding of the red planet is presently greater than it ever has been in the past. With multiple landers, orbiters and rovers probing the Martian terrain, we're learned so much about the nearest neighboring planet that wouldn't boil our insides in a matter of seconds.

Image credit: NASA / JPL-Caltech / Cornell / Arizona State Univ.

But many of us dream not of learning about the geologic history of Mars nor of sending robotic explorers there, but of sending humans there, with possible long-term goals ranging from creating a permanent human outpost there to terraforming the entire planet to be potentially habitable to human beings.

Image credit: Wikimedia commons user Daein Ballard, under the GFDL.

The first step, of course, is landing a human being on Mars. Recently, there's been talk of developing a nuclear fusion engine that could cut the trip-time down to a mere 30 days, from the more usual 250 days. Although it's possible to get to Mars more quickly, we're much more concerned with getting to Mars these days using the least amount of energy, which also requires waiting for the proper launch window, something that occurs every 780 days between Earth and Mars.

Image credit: Georgia Tech's Satellite Communications & Navigation course.

Now, nuclear fusion would, of course, be an incredible boon to both interstellar spaceflight and to Earth's energy needs. Crackpot claims about cold fusion aside, nuclear fusion is the holy grail of energy, is a completely clean source of energy, has the ingredients for it in abundance here on Earth, and is a process that's known to happen throughout the Universe.

Image credit: ESA & NASA; Acknowledgments: D. de Martin and E. Olszewski.

Not just in stars, of course, where nuclear fusion is the process that powers the vast majority of them, but here on Earth, where we've achieved controlled nuclear fusion successfully in at least three different general ways.

Image credit: National Ignition Facility.

1.) Inertial Confinement Fusion. We take a pellet of hydrogen -- the fuel for this fusion reaction -- and compress it using many lasers that surround the pellet. The compression causes the hydrogen nuclei to fuse into heavier elements like helium, and releases a burst of energy. Unfortunately, we have not yet reached the break-even point, as it still takes more energy to operate the lasers than we've been able to get out of any fusion reaction we've created.

Image credit: ITER (International Thermonuclear Experimental Reactor).

2.) Magnetic Confinement Fusion. Instead of using mechanical compression, why not let the electromagnetic force do the confining work? Magnetic fields confine a superheated plasma of fusible material, and nuclear fusion reactions occur inside this Tokamak-style reactor. This concept was first used to fuse elements beginning in the 1950s, and since that time, Magnetic Confinement and Inertial Confinement have gone back-and-forth as each one inches closer to the break-even point, where the fusion energy out will exceed the input energy. That point has not yet been reached.

Image credit: General Fusion, Inc.

3.) Magnetized Target Fusion. In MTF, a superheated plasma is created and confined magnetically, but pistons surrounding it compress the fuel inside, creating a burst of nuclear fusion in the interior. This clever hybrid approach was developed by Michel Laberge, and has successfully fused hydrogen into helium, but has not overtaken either ICF or MCF as the closest candidate to the break-even point.

Of course, the new candidate approach for a Fusion Driven Rocket is different from all of these in detail, but is worth a look.

Image credit: University of Washington's Plasma Dynamics Lab, MSNW.

In this approach, a magnetically confined plasma has large metal rings built around it, which are made to implode and compress the plasma, which will not only trigger a fusion reaction, but also will expel the high-energy particles in one direction, creating a fantastic amount of thrust. It is, at this point, an unproven concept, but it's definitely worth keeping an eye on to see how it develops.

But this new possibility for nuclear fusion and a current mission to Mars are two separate issues, and should be handled totally separately. For the fusion issue, we should be working tirelessly to develop nuclear fusion; if we can make it work, we will have literally tens of thousands of years worth of clean energy, regardless of the fuel mechanism used. Yet it's presently funded at the rate of about one billion Euros a year in the EU (and a little less than that here in the USA), which is part of the reason that fusion progress happens slowly.

Image credit: NASA/JPL-Caltech.

On the other hand, we can be on Mars in less than a decade, if we want to. This has been true since the 1990s (at least); it just requires a sustained investment in getting there using the technology we already have. I don't even care if it takes a reality show to get us there, the important thing is to invest in going one step at a time, and that means taking that very first step -- putting a human on Mars -- is maybe the most important step of all.

We have the fundamental rocket and life-support technology and the know-how, and we have thousands upon thousands of people willing to go, even if they know they're going on a one-way trip. We have the will and we have the manpower, all we need is a sustained vision for us to get behind, and -- in less than a decade -- we'll take our species' first steps on another planet.

Image credit: Stefan Morrell. Sources: Christopher McKay, NASA Ames Research Center; James Graham, University of Wisconsin–Madison; Robert Zubrin, Mars Society; Margarita Marinova, California Institute of Technology.

Yes, it's fun to dream about the far future on Mars, but the important thing -- if we're at all serious about following our dreams into space -- is to take the first step now, and send humans to the red planet. We should never pin our hopes of going to Mars on the development of fundamentally new technology, or it will never happen on the timescales that we want it to. We're all longing for the stars, but on its own, longing is only going to get us so far.

Image credit: Jason Kinnan.

We need to invest in the long-term future like it's our only hope, while simultaneously stepping forward in the present to bring that future to reality. Whether we invest in nuclear fusion or not, we should be sending human beings to Mars. Whether we send human beings to Mars or not, we should be investing in nuclear fusion. And if-and-when we do develop and control nuclear fusion, it won't be a quicker trip to Mars that we set our sights on, but ever farther and more remote targets. There's a whole Universe out there, and shame on us if we choose not to explore it.

That's my vision on a mission to Mars, that's my vision on nuclear fusion, and that's my vision and hope for the future of humanity in this Universe.