Structure
Space capsules have typically been smaller than 5 meters in diameter, although there is no engineering limit to larger sizes. As the capsule is both volumetrically efficient and structurally strong, it is typically possible to construct small capsules of performance comparable in all but lift-to-drag ratio to a lifting body or delta wing form for less cost. This has been especially pronounced in the case of the Soyuz manned spacecraft. Most space capsules have used an ablative heat shield for reentry and been non-reusable. The Crew Exploration Vehicle appear likely, as of December 2005, to be a ten-times reusable capsule with a replaceable ablative shield. There is no limit, save for lack of engineering experience, on using high-temperature ceramic tiles or ultra-high temperature ceramic sheets on space capsules.
Materials for the space capsule are designed in different ways, like the Apollo’s honey-combed structure of aluminum. Aluminum is very light, and the structure gives the space capsule extra strength. The early space craft had a coating of glass embedded with synthetic resin and put in very high temperatures. Carbon fiber, reinforced plastics and ceramic are new materials that are constantly being made better for use in space exploration.
Read more about this topic: Space Capsule
Famous quotes containing the word structure:
“The question is still asked of women: “How do you propose to answer the need for child care?” That is an obvious attempt to structure conflict in the old terms. The questions are rather: “If we as a human community want children, how does the total society propose to provide for them?””
—Jean Baker Miller (20th century)
“The structure was designed by an old sea captain who believed that the world would end in a flood. He built a home in the traditional shape of the Ark, inverted, with the roof forming the hull of the proposed vessel. The builder expected that the deluge would cause the house to topple and then reverse itself, floating away on its roof until it should land on some new Ararat.”
—For the State of New Jersey, U.S. public relief program (1935-1943)
“What is the structure of government that will best guard against the precipitate counsels and factious combinations for unjust purposes, without a sacrifice of the fundamental principle of republicanism?”
—James Madison (1751–1836)