One thing that’s always a big issue for any project in space is how you’re going to power whatever you’re sending up there. As it turns out the methods that we use to generate power up in space are extremely varied and in fact many of them paved the way for technologies we now use back here on earth. However there are still some advances to be made and if we are to return to the moon and beyond there will have to be a breaking down of some old barriers in order to enable us to go further into space.
Many of the initial space craft that were sent up just had your traditional chemical batteries in them. For the most part these worked well, and since they had been around for such a long time they were a proven technology (something that is critical in any space endeavour). As time went on and missions became much more ambitious NASA moved from batteries to fuel cells and were the first to fly these in a space craft on their Gemini missions. Fuel cells are advantageous because not only do they produce power, but typically a decent amount of heat and water as well. In fact they are still used to power the space shuttle and will typically produce around 500 litres of water on whilst in space. This is invaluable as that’s 500Kg less water they have to bring with them and 500Kg more they can take into orbit.
Satellites are another matter entirely. Since they don’t need any of those bothersome human things like water and heat fuel cells aren’t the right choice for them and the majority of artificial satellites in orbit around earth and our nearby neighbours use good old fashioned solar power. At the distance we are from the sun the available power is somewhere in the order of 1400W/m² but that drops off dramatically as we reach further out into the solar system. In fact the amount of power available past mars is so little compared to where we are that there is only one mission currently scheduled to Jupiter that uses solar panels called Juno.
So what do we use when we want to explore the deep reaches of space? The current technology used in most missions is called a Radioisotope Thermoelectric Generator (RTG) which in essence uses heat from decaying radioactive material to provide heat and electricity. In the past they’ve coped a lot of flack for using these as environmental groups lament the potential for damaging the environment and spreading nuclear material across the earth. NASA has done extensive research on the matter but still runs up against endless red tape whenever they try to use one. The usefulness of these devices really can’t be overstated as they’ve given us such missions such as Voyager 1, which has been going strong for over 30 years and is slated to last for at least another 15. This kind of technology is going to form the basis of any mission that attempts to leave our solar system.
NASA has begun to make inroads into producing small nuclear reactors that would be used to power a moon base. For any kind of long duration time in space us humans need quite a lot more power than our robotic counterparts and we won’t be able to use RTGs to satisfy this requirement. Whilst I do understand some of the environmental concerns if I was going to trust anyone sending nuclear material into space it would be NASA, as they have a long track record of getting hazardous materials out of our atmosphere without incident. Unfortunately the environmentalists haven’t seen it that way, and continually put up roadblocks which inhibit progress.
Eventually though I’m sure we will be able to power our space based devices using nuclear power without the worry and red tape that we have now. As time goes by NASA and other space agencies will prove that the technology is sound after repeated launches and the controversy will be nothing but a memory. It is then we can start to look further out into our solar system, and hopefully, beyond.