Propulsion
Spacecraft drive propulsion types and descriptions
Gravity Propulsion
Gravity-Assisted In the early 1960s, a graduate student named Michael Minovitch working at JPL developed a way to use a planet’s gravitation as a method of propulsion. Gravity-assisted maneuvers work by transferring angular momentum from an orbiting planet to a passing spacecraft. A spacecraft’s trajectory is adjusted so that it will make a fairly close... »
Chemical Propulsion
Chemical Advanced Chemical Propulsion Since we have already developed many different types of chemically-fueled propulsion systems, one might wonder why we need to advance these technologies. Historically, there has been a demand for improvements in many areas, such as safety, reduced mass, and of course increased specific impulse (Isp). Modern chemical propulsion systems utilize from one to... »
Nuclear Propulsion
Nuclear Thermal Radiation created by nuclear technologies is dangerous to both humans and their machines. Any use of nuclear propulsion technology would have to be accompanied by the use of extensive shielding and “hardening.” The potential advantages of nuclear propulsion over chemical methods are staggering. The energy that is available from nuclear reactions (fission, fusion, and... »
Electric Propulsion
Electric (Ion) Propulsion Electric propulsion works by using electrical energy to accelerate a propellant to much higher velocities than is possible using chemical reactions. The most common propellant used in ion engines is xenon. Early experimental ion engines used mercury and caesium, but they proved hard to work with. At room temperature, mercury is liquid and... »
Solid Fuel Propulsion
Solid Fuel Solid-fuel rocket engines were the first engines created by man. They were invented by the Chinese in the 13th century and have been widely used since then. The “rocket’s red glare” in the American National Anthem, which was written in the early 1800’s, refers to the small solid-fuel rockets that were used to... »
Solar Propulsion
Solar Propulsion Interplanetary Solar Sails A solar sail is a spacecraft that has an immense, lightweight mirror attached to it. It derives its propulsion by being pushed by light reflecting off of the mirror, instead of traditional rocket engines. The light used could be supplied by sunlight or lasers placed in orbit. Sunlight exerts a very... »
Hybrid Propulsion
Hybrid A rubbery fuel Rocket propellants come in two parts, fuel and oxidizer, which work together to keep an engine burning. SpaceShipOne burns a material called hydroxy-terminated polybutadiene (HTPB), a common ingredient in tyre rubber, as fuel with nitrous oxide serving as the oxidizer. According to press statements by Scaled, the combination was chosen for SpaceShipOne after... »