NASAThe National Aeronautics and Space Administration (NASA ˈnæsə) is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research, and space research. Established in 1958, NASA succeeded the National Advisory Committee for Aeronautics (NACA) to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science.
MarsMars is the fourth planet and the furthest terrestrial planet from the Sun. The reddish color of its surface is due to finely grained iron(III) oxide dust in the soil, giving it the nickname "the Red Planet". Mars's radius is second smallest among the planets in the Solar System at . The Martian dichotomy is visible on the surface: on average, the terrain on Mars's northern hemisphere is flatter and lower than its southern hemisphere. Mars has a thin atmosphere made primarily of carbon dioxide and two irregularly shaped natural satellites: Phobos and Deimos.
AirglowAirglow (also called nightglow) is a faint emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky never to be completely dark, even after the effects of starlight and diffused sunlight from the far side are removed. This phenomenon originates with self-illuminated gases and has no relationship with Earth's magnetism or sunspot activity. The airglow phenomenon was first identified in 1868 by Swedish physicist Anders Ångström.
MesosphereThe mesosphere (ˈmɛsəˌsfɪər,_ˈmɛz-,ˈmiːsə-,-zə-; ) is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as altitude increases. This characteristic is used to define limits: it begins at the top of the stratosphere (sometimes called the stratopause), and ends at the mesopause, which is the coldest part of Earth's atmosphere, with temperatures below .
Outer spaceOuter space, commonly referred to simply as space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty; it is a near-perfect vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is .
North American X-15The North American X-15 is a hypersonic rocket-powered aircraft. It was operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15's highest speed, , was achieved on 3 October 1967, when William J. Knight flew at Mach 6.7 at an altitude of , or 19.
AirplaneAn airplane (American English), or aeroplane (Commonwealth English), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Worldwide, commercial aviation transports more than four billion passengers annually on airliners and transports more than 200 billion tonne-kilometers of cargo annually, which is less than 1% of the world's cargo movement.
ThermosphereThe thermosphere is the layer in the Earth's atmosphere directly above the mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet radiation causes photoionization/photodissociation of molecules, creating ions; the thermosphere thus constitutes the larger part of the ionosphere. Taking its name from the Greek θερμός (pronounced thermos) meaning heat, the thermosphere begins at about 80 km (50 mi) above sea level. At these high altitudes, the residual atmospheric gases sort into strata according to molecular mass (see turbosphere).
AeronauticsAeronautics is the science or art involved with the study, design, and manufacturing of air flight–capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies the aspects of "aeronautical Art, Science and Engineering" and "The profession of Aeronautics (which expression includes Astronautics)." While the term originally referred solely to operating the aircraft, it has since been expanded to include technology, business, and other aspects related to aircraft.
Atmospheric entryAtmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: uncontrolled entry, such as the entry of astronomical objects, space debris, or bolides; and controlled entry (or reentry) of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric entry, descent, and landing of spacecraft are collectively termed as EDL.
