The RL-10, which served as the power plant for NASA's upper-stage Centaur space launch vehicle, was the first rocket engine to use high-energy liquid hydrogen as a fuel. It has provided precisely controlled, reliable power for lunar and planetary explorations. The RL-10 embodied numerous advanced design features, including multiple use of its fuel with the "bootstrap cycle." The RL-10 is also capable of multiple restarts in space, which enables positioning of satellites or further escape of Earth's gravity.
WashingtonState: DCCountry: USAWebsite: http://www.asce.org/Project/Washington-Monument/Creator: Casey, Thomas Lincoln
Upon its dedication in 1885, the Washington Monument was the tallest structure in the world. Begun in 1848 to honor George Washington, the structure wasn't completed for over 36 years. Construction and financing problems slowed progress and the Civil War halted it completely.
The United States Capitol is among the most symbolically important and architecturally impressive buildings in the nation. Construction of the original Capitol began in 1793, but it has been through several additions and alterations. Over its lifetime, the Capitol building has been built, burnt, rebuilt, extended, and restored.