USAF in the context of "Unified combatant command"

An air force in the broadest sense is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army aviation or naval aviation units. Typically, air forces are responsible for gaining control of the air, carrying out strategic and tactical bombing missions, and providing support to land and naval forces often in the form of aerial reconnaissance and close air support.

The term air force may also refer to a tactical air force or numbered air force, which is an operational formation either within a national air force or comprising several air components from allied nations. Air forces typically consist of a combination of fighters, bombers, helicopters, transport planes and other aircraft.

Military aviation is the design, development and use of military aircraft and other flying machines for the purposes of conducting or enabling aerial warfare, including national airlift (air cargo) capacity to provide logistical supply to forces stationed in a war theater or along a front. Airpower includes the national means of conducting such warfare, including the intersection of transport and warcraft. Military aircraft include bombers, fighters, transports, trainer aircraft, and reconnaissance aircraft.

A laser weapon is a type of directed-energy weapon that uses lasers to inflict damage. Whether they will be deployed as practical, high-performance military weapons remains to be seen. One of the major issues with laser weapons is atmospheric thermal blooming, which is still largely unsolved. This issue is exacerbated when there is fog, smoke, dust, rain, snow, smog, foam, or purposely dispersed obscurant chemicals present. In essence, a laser generates a beam of light that requires clear air or a vacuum to operate.

Laser-based directed energy weapons generally have two primary types: low-power laser dazzlers that blind optical systems or human eyes, and high-power lasers that can physically damage or destroy targets, such as enemy aircraft and ammunition.

In current military parlance, a strike fighter is a multirole combat aircraft designed to operate both as an attack aircraft and as an air superiority fighter. As a category, it is distinct from fighter-bombers, and is closely related to the concept of interdictor aircraft, although it puts more emphasis on aerial combat capabilities.

Examples of notable contemporary strike fighters are the American McDonnell Douglas F-15E Strike Eagle, Boeing F/A-18E/F Super Hornet and Lockheed F-35 Lightning II, the Russian Sukhoi Su-34, and the Chinese Shenyang J-16.

This is a list of all crewed spacecraft types that have flown into space, including sub-orbital flights above 80 km, space stations that have been visited by at least one crew member, and spacecraft currently planned to operate with crews in the future. It does not contain crewed flights by spacecraft below 80 km. There is some debate concerning the height at which space is reached (the Karman Line): the Fédération Aéronautique Internationale (FAI) recognizes 100 km, while NASA and the USAF recognize this as 50 miles (approx 80 km).

Since the first crewed spaceflight of Vostok 1 in 1961 there have been 13 types of spacecraft that have made crewed flights into space – nine American, three Russian, and one Chinese. There are currently five operational crewed spacecraft, which form the first part of the list below; the eight retired spacecraft types are listed in the next section; and crewed spacecraft currently in development are listed last. Space stations are listed beneath each appropriate section, dates of operation reflect when the first and last crews visited, not when they were launched and deorbited. There are currently two space stations in orbit around Earth, the International Space Station and the Chinese Tiangong space station.

In the U.S. Air Force (USAF), a boom operator is an aircrew member aboard tanker aircraft who is responsible for safely and effectively transferring aviation fuel from one military aircraft to another during flight (known as aerial refueling, air refueling, in-flight refueling, air-to-air refueling, and tanking). The name boom operator implies that one "operates a boom" (the flying boom), which is a long, extendable metal arm attached to the rear underside of the tanker that the boom operator connects to the fuel receptacle of a receiving aircraft (the receiver). The boom operator also controls the refueling drogue, a basket attached to a flexible hose that trails the tanker, when using the probe-and-drogue system. The USAF officially designates the boom operator career field as "In-Flight Refueling" with a specialty code of 1A0X1. However, this designation is usually reserved for administrative paperwork such as enlistment contracts and performance reports, as boom operators themselves are rarely referred to as in-flight refueling specialists within the USAF. The title "Boom Operator" is most commonly used, in reference to the aircrew position they occupy on the airplane, as noted in USAF regulations and aircraft flight manuals. Fellow crew members affectionately address them as "boom" or "boomer" (though the use of the term "boom" in this article refers to the flying boom, not the boom operator).

The boom operator crew position was created in 1948 when Boeing developed the flying boom at the request of the USAF. Prior to this, when the only practical means of transferring fuel was through a hose, other crew members fulfilled the duty of operating the air refueling equipment, such as the hose reel operator in the DH-4B and C-1 and the line operator in the B-24D and KB-29M using the grappled-line looped hose system. In the modern U.S. military, the boom operator crew position only exists in USAF tankers equipped with a flying boom, such as the KC-135, KC-10, and the newly developed KC-46. For tanker aircraft not equipped with a flying boom, such as the KC-130, HC-130, and F/A-18E/F, the specific crew member(s) responsible for operating the air refueling equipment and supervising refueling operations varies by aircraft. Boom-equipped tankers have been obtained by several foreign countries as a result of USAF tanker procurement programs and U.S. foreign military sales. An estimated 63 boom-equipped tankers (KC-135, KC-10, A330 MRTT, KC-767, and KC-33) are operated by 14 foreign countries; in comparison, the USAF operates 457 KC-135 and KC-10 tankers.