Atmosphere of Earth the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km (6,200 mi; 33,000,000 ft) where it merges into the solar wind. This layer is mainly composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen and carbon dioxide closer to the exobase. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another. Thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may
Gas turbine gas-turbine powered ship was the U.S. Coast Guard's , a cutter commissioned in 1961 that was powered by two turbines utilizing controllable-pitch propellers. The larger High Endurance Cutters, was the first class of larger cutters to utilize gas turbines, the first of which () was commissioned in 1967. Since then, they have powered the U.S. Navy's s, and s, and guided missile cruisers. , a modified , is to be the Navy's first amphibious assault ship powered by gas turbines. The marine gas turbine operates in a more corrosive atmosphere due to the presence of sea salt in air and