Rockets in the Future
Rockets are one of the most unique and amazing creations of humankind, and they are also one of the most useful. Rockets can transport satellites, supplies and even humans into space. Currently, some entrepreneurs are even contemplating space traveling and trips to other planets. However, the chemical rocket engines of today are barely powerful enough to get humans to Mars, and even that can only be done once every 26 months. Chemical engines are just not strong enough to create the thrust to go further. But what if there were other, more powerful engines that could take us deeper into space? Read more to find out!
Nuclear Engines
Nuclear energy has always been one of the most fascinating concepts ever, although not one of the most successful. During the late 19th century, several countries attempted to use nuclear energy to power their cities and towns, and many projects were successful. However there were a handful of reactor meltdowns, causing most nuclear power plants to be shut down due to the fear of a calamity. Nuclear energy was also something that was going to be used by NASA in the 1960's for rockets in the Nuclear Thermal Propulsion (NTP) project and the Nuclear Engine for Rocket Vehicle Application (NERVA) program. However, due to budget cuts and technological barriers, the projects weren't completed. However, recently with countries planning to go to Mars and beyond, these old projects have been brought back to consideration, especially since the technology has exponentially improved since the 60's.
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The Nuclear Thermal Propulsion engine is designed to have a nuclear reactor and a liquid hydrogen tank in it. The nuclear reactor would contain a marble sized ball of uranium, which undergoes fission, which releases colossal amounts of heat and energy. The liquid hydrogen is then heated to about 2,500 degree Celsius, and is expelled at a very high exhaust velocity out of the rocket nozzle. This process produces about 2 to 3 times as much thrust as a regular liquid propellant rocket. While it is more dangerous to have a nuclear reactor in a rocket because of radiation and chances of a meltdown, nuclear thermal rocket engines are more effective and are lighter to carry. Estimations show that a nuclear thermal rocket can get to Mars in a 100 days, compared to 8 months on a chemical rocket. Also, nuclear rockets also give the flexibility to be launched to Mars at any time because of their power, rather than only being able to launch once every 26 months with a chemical rocket.
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Nuclear rockets are also going to be safer now that scientists are more experienced with nuclear power and because the technology to protect a nuclear reactor is better. Also, NASA is planning to use low-enriched uranium in its nuclear rocket engines instead of highly enriched uranium because it is safer and more predictable while also producing tremendous amounts of energy. Nuclear rockets are now safer and better understood, making them the perfect model for the future.
Plasma Thrust Engines
Plasma is the fourth state of matter, and it is one that is not commonly known or found. Plasma is basically an ionized gas, and it is created by adding heat and energy to a gas. This can be done in various ways, for example by focusing solar energy onto the gas, by providing the energy of a nuclear reactor to a gas or by passing radio waves through the gas. By adding some form of heat and energy to the gas, the electrons that surround the gas' atoms gets stripped away from it, leaving only the positively charged nucleus intact. These positive nuclei together form a plasma.
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Plasma Thrust Engines are a relatively new invention with huge potential for use in the real world. Currently, the best plasma engine project is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine development project. The idea of the engine is to ionize gas using electric fields or radio waves, which will produce plasma by stripping away the atoms' electrons. The plasma is then passed through a magnetic field, which focuses and directs the plasma, which is then shot out of the nozzle at the back of the rocket. This expulsion of plasma creates a lot of thrust which pushes the rocket upward. Many different gases can be used as the input for the VASIMR Engine, like hydrogen, helium and deuterium.
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The main reason to use a plasma engine is the ease of access to fuel. Hydrogen is the most common element in the entire universe, and hydrogen gas is very accessible, even outside fo Earth. This means that it is easy to get fuel for the VASIMR engine, and that makes a rocket with a VASIMR engine relatively cheap. Also, hydrogen gas can be found even on Mars, meaning that the rocket only needs to be fueled for a one sided trip to the Red Planet, and it can be easily refueled over there as well. Another benefit is that, in comparison to a chemical rocket that uses liquid propellants, hydrogen gas is light, meaning that the overall mass of the rocket reduces as well. Also, the hydrogen gas can be used to insulate the rocket being launched, to protect the astronauts from radiation. This is because hydrogen gas is known to be one of the best shields for radiation. Finally, and most importantly, the VASIMR engine also produces more thrust than a conventional chemical rocket, allowing the rocket to reach the destination faster. All these benefits combined make the VASIMR engine one of the most promising designs of the future.
