History
Many orbital expendable launchers are derivatives of 1950s-era ballistic missiles. Many see this as unfortunate because cost was not a major consideration in their design. A prime example of this is the Titan IV, probably the costliest per-unit launch vehicle in history (perhaps following the Space Shuttle).
On the other hand, a reusable launcher such as the Shuttle requires a heavier structure and a recovery system (wings, thermal protection system, wheels, etc.) that reduce payload capacity. The Shuttle additionally carries a crew (though not inherent to a reusable system) whose weight, supplies and life support systems further decrease payload capacity.
A Shuttle orbiter is a major national asset, and its high cost (far more than a single expendable launch vehicle) and presence of a crew require stringent "man rated" flight safety precautions that increase launch and payload costs. Only five orbiters were built, and the loss of two (Challenger and Columbia) significantly impacted the capacity and viability of the Shuttle program. Each loss also resulted in an extended hiatus in Shuttle flights compared to that following most expendable launch failures, each of which impacted only that model of launcher.
For these reasons it is generally agreed that the Space Shuttle has not delivered on its original promise to reduce the costs of constructing and launching payloads into orbit. The Shuttle was originally intended to replace expendable launchers in the launching of satellites, but after the loss of Challenger the Shuttle was reserved for previously planned missions and those requiring a crew.
Spacecraft launched by the Shuttle included several TDRSS communications relays heavily used by the Shuttle program itself, a series of commercial communication satellites, and the interplanetary probes Magellan, Galileo and Ulysses. Several classified military payloads were also carried.
Read more about this topic: Expendable Launch System
Famous quotes containing the word history:
“All things are moral. That soul, which within us is a sentiment, outside of us is a law. We feel its inspiration; out there in history we can see its fatal strength.”
—Ralph Waldo Emerson (1803–1882)
“Bias, point of view, fury—are they ... so dangerous and must they be ironed out of history, the hills flattened and the contours leveled? The professors talk ... about passion and point of view in history as a Calvinist talks about sin in the bedroom.”
—Catherine Drinker Bowen (1897–1973)
“The principle that human nature, in its psychological aspects, is nothing more than a product of history and given social relations removes all barriers to coercion and manipulation by the powerful.”
—Noam Chomsky (b. 1928)