10-04-2017, 07:43 PM
Non-rocket spacelaunch is the idea of reaching outer space mainly without the use of rockets, which today is the only method in use. Transportation to orbit is often the limiting factor in space endeavours. Present-day launch costs are very high $3,000 to $25,000 per kilogram from Earth to Low Earth Orbit (LEO). To settle space, e.g. space exploration and space colonization, much cheaper launch methods are required, as well as a way to avoid serious damage to the atmosphere from the thousands, perhaps millions, of launches required. Many alternatives to conventional rockets have been proposed: * A space tower is simply a conventional tower all the way up to outer space * A conventional space elevator is a tether spanning from the surface to a point beyond geosynchronous orbit * A space fountain is an elevator variant held up by a constant particle stream * An orbital ring is an elevator variant spanning from the surface to a cable rotating around the planet * A mass driver is a very long vacuum pumped accelerator * A launch loop is a cable held at high altitude by magnetic levitation * A space gun is a cannon with a very long gun barrel * A spaceplane is a plane designed to reach outer space