NASA scientists have been saying for some time that they plan to send a manned mission to Mars by 2030. At the same time, space adventurist Dennis Tito and his company Inspiration Mars want to send a couple on a flyby of the Red Planet in 2018. With such ambitions fueling investment and technological innovation, its little wonder why people feel we are embarking on the new era of space exploration.
However, there is one sizable problem when it comes to make the Mars transit, which is the wait time. In terms of Tito’s proposed flyby, a trip to Mars when it is in alignment with Earth would take a total 501 days. As for NASA’s round-trip excursions for the future, using current technology it would take just over four years. That’s quite the long haul, and as you can imagine, that longer transit time has an exponential effect on the budgets involved!
But what if it were possible to cut that one-way trip down to just 30 days. That’s the question behind the new fusion rocket design being developed at the University of Washington and being funded by NASA. Led by John Slough, this team have spent the last few years developing and testing each of the various stages of the concept and is now bringing the isolated tests together to produce an actual fusion rocket.
The challenge here is to create a fusion process that generates more power than it requires to get the fusion reaction started, a problem which, despite billions of dollars of research, has eluded some of the world’s finest scientists for more than 60 years. However, researchers continue to bang their head on this proverbial wall since fusion alone – with its immense energy density – appears to be the way of overcoming the biggest barrier to space travel, which is fuel weight and expense.
Ultimately, the UW fusion rocket design relies on some rather simple but ingenious features to accomplish its ends. In essence, it involves a combustion chamber containing rings made of lithium and a pellet of deuterium-tritium – a hydrogen isotope that is usually used as the fuel in fusion reactions. 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, causing a massive explosion that ejects the metal rings out of the rocket and at 108,000 km/h (67,000 mph) and generating thrust. This reaction would be repeated every 10 seconds, eventually accelerating the rocket to somewhere around 320,000 km/h (200,000 mph) — about 10 times the speed of Curiosity as it hurtled through space from Earth to Mars.
However, things still remain very much in the R&D phase for the fusion rocket. While the team has tested out the imploding metal rings, they have yet to insert the deuterium-tritium fuel and propel a super-heated ionized lump of metal out the back at over 100,000 kilometers and hour. That is the next – and obviously a very, very – big step.
But in the end, success will be measured when it comes to two basic criteria: It must work reliably and, most importantly, it must be capable of generating more thermal energy than the electrical energy required to start the fusion reaction. And as already mentioned, this is the biggest challenge facing the team as it is something that’s never been done before.
However, most scientific minds agree that within 20 years at least, fusion power will be possible, and the frontiers it will open will be vast and wonderful. Not only will we be able to fully and completely lick the problem of clean energy and emissions, we will have rockets capable of taking us to Mars and beyond in record time. Deep space flight will finally become a possibility, and we may even begin considering sending ships to Alpha Centauri, Bernard’s Star and (fingers crossed!) Gliese 581!