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Launch costs for sending payloads to low earth orbit range from $10,000 to $25,000 per kilogram. Chemical rockets have kept costs high, but equatorial launches and private spaceflight have helped. New methods, such as a cannon or space elevator, could reduce costs significantly.
Launch costs refer to the cost of sending a payload from earth to outer space, specifically low earth orbit (LEO). Typical launch costs today range from $10,000 US dollars (USD) to $25,000 USD per kilogram ($4,500 to $11,000 USD per pound), although some countries subsidize space launches, occasionally reducing costs as low as $4,000 USD per kilogram ($1,800 USD per pound). For a typical five-ton communications satellite, this amounts to between $20 million USD and $125 million USD. For the launch of the Space Shuttle, which weighs about 2,000 tons, the cost is about 800 million dollars, or almost a billion dollars. Including other expenses, the average total cost per Space Shuttle flight is approximately $1.5 billion USD. Clearly, this makes space activities expensive.
Launch costs have been much the same since the early days of space exploration, mainly due to an unchanging underlying technology: chemical rockets. The costs of launching a chemical rocket have been reduced somewhat through innovation (private spaceflight) and equatorial launch services (such as Sea Launch). Launching a rocket from the equator can minimize the fuel needed by taking advantage of the Earth’s rotation, thus reducing launch costs by a significant margin. Launch costs can be reduced somewhat by using reusable launch vehicles, but the poor cost performance of the reusable Space Shuttle has caused many to question this idea. There is consensus that a real breakthrough in reducing launch costs will require using a new method to get to space.
Ever since space travel began with the launch of Sputnik in 1957, scientists have looked for ways to use a method other than chemical rockets to reach space. It has been determined that a long enough cannon could be used to launch acceleration-resistant payloads into space, but no country has yet tried to build one, although some companies are trying. A similar concept, a launch loop, would accelerate a payload using powerful magnets to escape velocity, then launch it straight up. Such an approach would also require acceleration-resistant payloads, since accelerations on the payload would be in the range of thousands of gravities.
Another proposed method of reducing launch costs is the construction of a space elevator, a concept that may receive funding and attention in the United States and Japan. A space elevator would consist of an extremely long carbon nanotube cable, with a counterweight in geosynchronous orbit. While reaching orbit would still require the same amount of energy, it could be expended gradually rather than over the course of a few minutes, greatly expanding the number of options that could be used to get a payload into orbit.
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