to the stars and beyond
What’s the rarest and most expensive substance on our planet? No, it’s not platinum or gold or diamonds. Give up? It’s antimatter. Created for fractions of a millisecond by colliders and giant lasers, a single gram costs some $60 trillion according to a 1999 NASA estimate. Now, a recent experiment at the Lawrence Livermore National Laboratory might lower that cost. Apparently, when a short burst of a powerful laser hits a millimeter thin sliver of gold, it produces over 100 billion antimatter particles. The scientists at the laboratory plan to use their new technique for making positrons to study high energy physics. But there might be a very interesting practical application for their experiment in the near future.
Now you might be wondering what such an explosive, expensive and short lived particle could do for us outside of a lab. Because matter/antimatter reactions are 100% efficient, futurists and sci-fi authors thought it would be a good way to make cheap energy. Unfortunately, that’s not going to happen anytime soon. Because it takes trillions of watts to create positrons in the first place, the end result will be a net loss. However, positrons have another use. For the last twenty years, engineers started drawing up plans for an antimatter engine which uses quick injections of positrons as an accelerant.
A spaceship using this propulsion method could go from Earth to Mars in just 45 days using around 10 milligrams of positrons. The biggest challenge for the current engine design is the fact that antimatter annihilates matter and would need to be suspended in powerful magnetic fields. Now, if we were to use a technique similar to the Lawrence Livermore experiment, rather than worry about containing antimatter and hoping the containment doesn’t fail, taking out the engine and crippling the craft, we could make it on board and funnel it into a reaction chamber in just fractions of a second. No need to strap a giant particle accelerator to the craft since you won’t need it anymore.
Using antimatter catalyzed engines makes planetary exploration easier, faster and much more efficient. It also opens up the possibility of traveling to the stars as we tweak the engine design for optimal power and develop the technology needed to keep crews alive and well on a journey through interstellar space. It looks like interplanetary travel and relativistic rockets just got one step closer to reality.
[ illustration by Rory McLeish ]
