 Nuclear energy has grown on us over the years. In fact, in France alone, nuclear energy is used to generate around 68% of the country's electricity. Aside from producing a sustainable amount of clean energy, going nuclear could help us in our efforts to venture out into space. In our third installment of the Helium-3 series, we explained the science of how Helium-3 could be used as an efficient, clean, and very powerful fuel source for rocket propulsion, as opposed to the traditional liquid hydrogen and oxygen fuels used in modern chemical rockets. So please watch that video if you haven't already. If you are all caught up then, join us today as we take a short and concise look at how Helium-3 could be used in a spacecraft from both a safety and power efficiency perspective. First things first, nuclear fusion can be quite hot. Helium-3 and deuterium fusion reactions are approximated to take place well in excess of at least 100 million Kelvin, with some estimates stating the conditions for the fusion can be as hot as around 600 million Kelvin. In order to contain such a reaction, it's likely a Tokamak would have to be constructed. Tokamaks are torus-shaped machines which use powerful magnetic fields that can contain thermonuclear fusion reactions. The magnetic field will prevent the high-energy byproducts of the fusion from damaging and melting the surrounding ship components. It also helps that the fusion of Helium-3 and deuterium doesn't release those dangerous high-energy neutrons, which are trickier to handle since they can't be contained within a magnetic field due to their lack of charge. Aside from safety, power is also important. After all, we need electricity to sustain many of the ship's functions. Typically, nuclear reactions on earth produce electricity by using the heat released from fusion to heat up water. When the water boils, steam is released, and this steam can be used to rotate a turbine that generates electricity by altering the magnetic fields around the coils it is rotating within. But this usually only results in about 33-40% of the nuclear energy successfully being converted to usable electricity. There could be another way though. Because Helium-3 deuterium fusion releases a lot of its energy in the form of charged particles, a process called direct collection can be used to convert the kinetic energy of these charged particles into electrical energy. There are different types of direct collection devices that could be incorporated into a ship, such as a Venetian blind collector, E-Times B collector, cyclotron resonance collector, traveling wave direct energy converter, and a magnetohydrodynamic generator. While we don't have time to go into each one individually, it is important you understand all these collectors utilize various mechanisms, such as electric and magnetic fields, grid structures, and positive and negative potentials to separate ions in the fusion byproducts from their electrons. These ions are then collected on high voltage plates, which can be used to generate an electrical current. It is likely one of these devices or combination of these devices can be used in conjunction with each other to maximize the efficiency of the energy conversion. Estimates state that up to 70% of the fusion energy can be converted into electricity using these techniques, making it far more efficient than the steam turbine. At this point, it's just a question of size and scalability for a spacecraft, as well as what material should be used in the construction to ensure it can handle the immense heat as well as any potential radiation. And don't forget the rigorous amount of testing and experimentation needed to make sure these systems are viable on a spacecraft. At the end of the day, the most important fact facing us is that the road to a fusion-based propulsion future in space exploration is filled with many engineering and scientific bridges that need to be crossed. Though today's video was short, we hope this simplified summary of a Helium-3-powered spacecraft design gave you a basic understanding of the types of challenges and engineering feats that need to be addressed without confusing you with too much details. For more updates on Helium-3, as well as other mysteries of the cosmos, be sure to stay tuned for more science videos.