Fusion breakthrough and space exploration
The recent Lawrence Livermore breakthrough, in which scientists created more energy from a fusion reaction than it took to create it, has uses applicable to space exploration. Fusion, harnessing the sun's power to smash atoms together to create virtually limitless energy, has moved from a scientific problem to an engineering challenge.
The task ahead is to develop the hardware necessary to create sustained fusion reactions that could, in turn, generate clean energy that will make fossil fuels, along with solar, wind and nuclear energy obsolete. The task will take years if not decades to come to fruition.
The first effect of the fusion breakthrough on space exploration will be to help transform the moon from a realm of scientific exploration to a source of resources that will transform the world's economy. The key is an isotope called helium-3, deposited on the lunar surface over billions of years by solar wind.
The Lawrence Livermore experiment involved using lasers to strike a capsule filled with deuterium and tritium, both hydrogen isotopes. Deuterium/tritium fusion produces radioactive neutrons that over time damage the containment vessel of a fusion reactor. Every 10 years or so the reactor would have to be taken offline for decontamination.
Deuterium/helium-3 fusion creates far fewer radioactive neutrons. However, creating and sustaining such a reaction is much more challenging than conventional deuterium/tritium. Nevertheless, a company called Helion Energy is developing such a reactor, using helium-3 manufactured onsite with a deuterium/deuterium fusion reaction.
In the long run, it might make more sense to mine helium-3 on the moon and bring it back to Earth to fuel future fusion reactors. A lunar mining industry and a moon-to-Earth supply chain that makes economic sense would take a long time to accomplish. But at the end of such an effort could be a human civilization free of climate change threat and possessing limitless energy to bring prosperity to everyone on Earth.
China recently claimed to have brought back a tiny amount of helium-3 from the moon. China has its own lunar ambitions, including developing fusion energy fueled by helium-3. The second effect concerns propulsion. Currently, using chemical rockets, Mars is months away while the Jupiter and Saturn systems are years away. Nuclear thermal propulsion rockets reduce the time needed to get to deep space destinations. However, fusion propulsion is the holy grail to open the solar system to human settlement.
A British company culled Pulsar Fusion is developing several propulsion technologies, including an intriguing hybrid rocket that uses high density polyethylene derived from recycled plastic waste. Pulsar is also building a fusion rocket engine, using deuterium/helium-3 reactions, that it claims will provide both propulsion and electric power for future spacecraft. The company claims it will start static tests in 2023 with an on-orbit test in 2027.
History informs us that the kind of timeline that Pulsar is claiming may be more aspirational than real. Both financial and technological hurtles are likely between now and the time when a working fusion engine is tested in space.
On the other hand, a fusion engine that takes the plasma created by the reaction and shoots it out a nozzle with electromagnets is a game-changing technology that will reduce the time it takes to travel to Mars and the outer planets by orders of magnitude. It's the kind of advance that will make the difference between occasional voyages into deep space for scientific exploration and turning the solar system, with all of its abundant resources, into a realm of human civilization.
Fusion energy, by enabling humankind's expansion into space, will create a far better, more prosperous future than many people imagine. Limitless fusion energy and limitless resources in space may be the keys to staving off that often-predicted dystopia of population growth and climate crises forever.