A question that pops up from time to time on sites like Quora goes like this. Humans went to the moon and back in the late 1960's and repeatedly into the 1970's, so why did we not go to Mars? Or back to the Moon? The simplest answer is usually the best and it runs - because the money dried up! NASA had a decent chunk of the American GDP through the Apollo program and once the Soviets had been bested, the funding was seriously pared back. No more lunar missions and certainly, no Martian adventures, for the meantime.

There were other reasons too. The technology that took men to the Moon was simply not up to a Martian trip. Take your mobile phone out of your pocket and look at it. Congratulations, your processing power is vastly superior to that available aboard these missions. The Moon is a three day journey each way. Mars, at best, will be a 21 month round trip! That is a massive difference in scale and difficulty and much else besides.

So now we are in a new space race, one in which Mars is a strong candidate for human exploration. There is a lot of anticipation and hype. Sure, technology has come a long way since those early days. There is talk of a manned mission before 2030, a mere 11 years away. A lot of work is being done but there are huge problems to overcome. The main one is simply this - how do humans survive in space over long periods of time? Zero gravity and radiation alone present serious long-term obstacles. The cocoon of the Earth protects and sustains us. Space really just wants to kill us.

A remote exploration of the Red planet still seems to be the best bet for now. Maybe we need a few more decades of innovation before we dare send people on such a dangerous mission. Robots can build living environments and perhaps even begin terraforming the surface, if that is possible. There is no point in sending folks to their certain deaths just for the sake of planting a flag. Or leaving a footprint.

"No, no, no - back to earth!"