Apollo programThe Apollo program, also known as Project Apollo, was the third United States human spaceflight program carried out by the National Aeronautics and Space Administration (NASA), which succeeded in preparing and landing the first humans on the Moon from 1968 to 1972. It was first conceived in 1960 during President Dwight D. Eisenhower's administration as a three-person spacecraft to follow the one-person Project Mercury, which put the first Americans in space. Apollo was later dedicated to President John F.
Shock waveIn physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan.
Speed of soundThe speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as well as the medium through which a sound wave is propagating. At , the speed of sound in air is about . More simply, the speed of sound is how fast vibrations travel. The speed of sound in an ideal gas depends only on its temperature and composition.
Interstellar travelInterstellar travel is the hypothetical travel of spacecraft from one star system, solitary star, or planetary system to another. Interstellar travel is expected to prove much more difficult than interplanetary spaceflight due to the vast difference in the scale of the involved distances. Whereas the distance between any two planets in the Solar System is less than 30 astronomical units (AU), stars are typically separated by hundreds of thousands of AU, causing these distances to typically be expressed instead in light-years.
Cabin pressurizationCabin pressurization is a process in which conditioned air is pumped into the cabin of an aircraft or spacecraft in order to create a safe and comfortable environment for humans flying at high altitudes. For aircraft, this air is usually bled off from the gas turbine engines at the compressor stage, and for spacecraft, it is carried in high-pressure, often cryogenic, tanks. The air is cooled, humidified, and mixed with recirculated air by one or more environmental control systems before it is distributed to the cabin.
International Civil Aviation OrganizationThe International Civil Aviation Organization (ICAO, ˌaɪˈkeɪˌoʊ ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international air transport to ensure safe and orderly growth. The ICAO headquarters are located in the Quartier International of Montreal, Quebec, Canada.
Air FranceAir France (ɛːʁ fʁɑ̃s; formally Société Air France, S.A.), stylised as AIRFRANCE, is the flag carrier of France headquartered in Tremblay-en-France. It is a subsidiary of the Air France–KLM Group and a founding member of the SkyTeam global airline alliance. , Air France serves 29 destinations in France and operates worldwide scheduled passenger and cargo services to 201 destinations in 78 countries (93 including overseas departments and territories of France) and also carried 46,803,000 passengers in 2019.
International Space StationThe International Space Station (ISS) is the largest modular space station in low Earth orbit. The project involves five space agencies: the United States' NASA, Russia's Roscosmos, Japan's JAXA, Europe's ESA, and Canada's CSA. The ownership and use of the space station is established by intergovernmental treaties and agreements. The station serves as a microgravity and space environment research laboratory in which scientific research is conducted in astrobiology, astronomy, meteorology, physics, and other fields.
Interplanetary spaceflightInterplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions.
Apollo Lunar ModuleThe Apollo Lunar Module (LM ˈlɛm), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed spacecraft to operate exclusively in the airless vacuum of space, and remains the only crewed vehicle to land anywhere beyond Earth. Structurally and aerodynamically incapable of flight through Earth's atmosphere, the two-stage lunar module was ferried to lunar orbit attached to the Apollo command and service module (CSM), about twice its mass.
