Closing in on Mars

Humans will never get over their fascination with Mars, the Red Planet. For a start, it is the most Earth-like planet out there, if we dismiss Earth’s real twin Venus which has unbearable conditions.

Mars is half in size, but a day on the Red Planet is also nearly 24 hours.

Mars is currently in the news due to several factors. The main reason is the spectacular success of NASA’s unmanned missions to Mars which are conducting surface expeditions and experiments as we write. NASA updates us almost every day on the activities of the Curiosity mission, which has already gathered evidence that Mars’ atmosphere was once dense enough to support liquid water on the surface. The Martian atmosphere is still active to some extent. With that comes the tantalising possibility that Mars may have harboured life at one stage or could be hosting rudimentary forms of life even now.

That is just one more reason why Mars should be the next destination for a manned space mission. However, with current propulsion technologies, that is a tall order - it will take a minimum of four years.

That may not seem bad, but we have to factor in how two or more people can spend four years scooped up in a metal tube. A faster journey will be much appreciated.

The answer could be nuclear energy. Many space probes are already nuclear powered (in conjunction with solar power) including Curiosity itself. However, we are talking about a different ‘take’ on nuclear energy - nuclear fusion, the safer, zero-emission alternative to nuclear fission, the current technology a la Hiroshima, Chernobyl and Fukushima. Nuclear fusion is the process that powers the Sun - a reaction that will go on for another 4.5 billion years.

A research group at the University of Washington, funded by NASA, is about to build a fusion-powered rocket. This rocket, if it can be successfully built, could propel a manned spacecraft to Mars in just 30 days - just one month and even other planets could get much closer.

Indeed, if we do not find a faster method of space travel, even the nearest planet outside the Solar System will be a staggering 200,000 years away..

Fusion is an ideal method of rocket propulsion, as fusion fuel has immense energy density - seven million times denser than conventional rocket fuel. The weight and expense of fuel are the biggest barriers to interplanetary/interstellar space travel.

The UW team has spent the last few years developing and testing each of the various stages of a fusion rocket. Now it is time to bring these isolated tests together to produce an actual fusion rocket. To succeed, Slough and co will need to create a fusion process that generates more power than it requires to get the fusion reaction started - a feat that, despite billions of dollars of research, has eluded the world’s finest scientists for more than 60 years.

Description

The website ExtremeTech has a description of what the new method is all about: “The UW fusion rocket design is mechanically simple and also ingenious. In essence, there’s a pellet of deuterium-tritium (hydrogen isotopes; the usual fuel used with fusion), and some large metal rings made of lithium. When the pellet is in the right place, flowing through the combustion chamber towards the exhaust, a huge magnetic field is triggered, causing the metal rings to slam closed around the pellet of fuel.

These rings then implode with such pressure that the fuel compresses into fusion - much in the same way that a car compresses diesel into combustion. The fusion causes a massive explosion, ejecting the metal rings out of the rocket at 108,000 kmh, generating thrust.

This reaction would be repeated every 10 seconds, eventually accelerating the rocket to somewhere around 200,000 miles per hour - about 10 times the speed of Curiosity as it hurtled through space from Earth to Mars.”

If the team at UW and other scientists around the world overcome this obstacle, not only will Mars be closer, but the Earth itself will also benefit by having a sustainable power source. A fusion process must work reliably and be capable of generating more thermal energy than the electrical energy required to start the fusion reaction. The moment that problem is overcome, fusion will be the way to go - to Mars and planets beyond.

Reactor

Apart from the team at UW, our best hope lies in the work that ITER (International Thermonuclear Experimental Reactor) is doing. A fusion reactor project backed by US, Russia, France, India, Korea, China, Japan and the EU, the ITER is on course to deliver reliable, safe nuclear fusion power. However, it could take another 20 years for the technology to become commercially viable. In the meantime, there is nothing like working feverishly to achieve this ultimate goal.

Fusion power or not, both Governments and private sector organisations are planning manned missions to Mars. Mars One is one such private sector initiative which plans a permanent settlement on Mars - it has no plans to bring the astronauts back to Earth. They hope to accomplish a manned mission to Mars by 2023, which is just 10 years away. A bit ambitious then, but certainly not impossible.

Mars is an exciting prospect because it is the only planet in the Solar System that could potentially be “terraformed” - in other words, made into an Earth-like planet. It will take hundreds of years with current technologies, but it is well worth a shot. Mars could be our second home and a base from which we could venture out to other worlds.

As for critics who say that exploring Mars is a huge waste of money, the more we learn about Mars and other planets, the more we learn about the Earth itself. Humans are curious by nature - we are born to explore. If that instinct gives us a chance to venture to other worlds, humankind will benefit in no small measure. After all, the Earth is not going to last forever. It will be great to have other homes around the Universe when that happens.