United States Space Force in the context of Space Launch Delta 30

The United States Department of Defense (DoD), also referred to as the Department of War (DoW), is an executive department of the U.S. federal government charged with coordinating and supervising the U.S. Armed Forces—the Army, Navy, Marines, Air Force, Space Force, and, for some purposes, the Coast Guard—and related functions and agencies. Headquartered at the Pentagon in Arlington County, Virginia, just outside Washington, D.C., the stated mission of the Department of Defense is "to provide the military forces needed to deter war and ensure our nation's security".

The Department of Defense is headed by the secretary of defense, a cabinet-level head who reports directly to the president of the United States. The president is commander-in-chief of the U.S. armed forces. Beneath the Department of Defense are three subordinate military departments: the Department of the Army, the Department of the Navy, and the Department of the Air Force. In addition, four national intelligence services are subordinate to the Department of Defense: the Defense Intelligence Agency, National Security Agency (NSA), National Geospatial-Intelligence Agency, and National Reconnaissance Office.

The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. Since 1949, all of the armed forces, except the Coast Guard, have been permanently part of the United States Department of Defense, with the Space Force existing as a branch of the Air Force until 2019. They form six of the eight uniformed services of the United States.

From their inception during the American Revolutionary War, the Army and the Navy, and later the other services, have played a decisive role in the country's history. They helped forge a sense of national unity and identity through victories in the early-19th-century First and Second Barbary Wars. They played a critical role in the territorial evolution of the U.S., including the American Civil War. The National Security Act of 1947 created the Department of Defense or DoD, (after a short period being called the National Military Establishment) headed by the secretary of defense, superior to the service secretaries. It also created both the U.S. Air Force and National Security Council; in 1949, an amendment to the act merged the cabinet-level departments of the Army, Navy, and Air Force into the DoD.

The United States Department of the Air Force (DAF) is one of the three military departments within the Department of Defense of the United States of America. The Department of the Air Force was formed on September 18, 1947, per the National Security Act of 1947 (codified into Title 10 of the United States Code) and it is the military department within which the United States Air Force and the United States Space Force are organized.

The Department of the Air Force is headed by the secretary of the Air Force (SAF/OS), a civilian, who has the authority to conduct all of its affairs, subject to the authority, direction and control of the secretary of defense. The secretary of the Air Force's principal deputy is the under secretary of the Air Force (SAF/US). Their senior staff assistants in the Office of the Secretary of the Air Force are five assistant secretaries for acquisition, technology & logistics; financial management & comptroller; installations, environment & energy; manpower & reserve affairs; and space acquisition & integration and a general counsel. The highest-ranking military officers in the department, and senior military advisers to the secretary, are the chief of staff of the Air Force and chief of space operations.

The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a GPS receiver anywhere on or near the Earth where signal quality permits. It does not require the user to transmit any data, and operates independently of any telephone or Internet reception, though these technologies can enhance the usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls, and maintains the GPS system, it is freely accessible to anyone with a GPS receiver.

A space force is a military branch of a nation's armed forces that conducts military operations in outer space and space warfare. The world's first space force was the Russian Space Forces, established in 1992 as an independent military service. However, it lost its independence twice, first being absorbed into the Strategic Rocket Forces from 1997–2001 and 2001–2011, then it merged with the Russian Air Force to form the Russian Aerospace Forces in 2015, where it now exists as a sub-branch. As of 2025, there are two independent space forces: the United States Space Force and China's People's Liberation Army Aerospace Force.

Countries with smaller or developing space forces may combine their air and space forces under a single military branch, such as the Russian Aerospace Forces, Spanish Air and Space Force, French Air and Space Force, or Iranian Islamic Revolutionary Guard Corps Aerospace Force, or put them in an independent defense agency, such as the Indian Defence Space Agency. Countries with nascent military space capabilities usually organize them within their air forces.

The IERS Reference Meridian (IRM), also called the International Reference Meridian, is the prime meridian (0° longitude) maintained by the International Earth Rotation and Reference Systems Service (IERS). It passes about 5.3 arcseconds east of George Biddell Airy's 1851 transit circle, and thus it differs slightly from the historical Greenwich Meridian. At the latitude of the Royal Observatory, Greenwich the difference is 102 metres (335 ft).

It is the reference meridian of the Global Positioning System (GPS) operated by the United States Space Force, and of WGS 84 and its two formal versions, the ideal International Terrestrial Reference System (ITRS) and its realization, the International Terrestrial Reference Frame (ITRF).

The United States Public Health Service Commissioned Corps (USPHSCC; also referred to as the Commissioned Corps of the United States Public Health Service) is the uniformed service branch of the United States Public Health Service and one of the eight uniformed services of the United States (along with the Army, Navy, Marine Corps, Coast Guard, Air Force, Space Force, and NOAA Commissioned Officer Corps). The commissioned corps' primary mission is the protection, promotion, and advancement of health and safety of the general public.

Along with the NOAA Commissioned Officer Corps, the Public Health Service Commissioned Corps is one of two uniformed services that consist only of commissioned officers and has no enlisted or warrant officer ranks, although warrant officers have been authorized for use within the service. Officers of the commissioned corps are classified as noncombatants, unless directed to serve as part of the military by the president or detailed to a service branch of the military. Members of the commissioned corps wear uniforms modeled after the United States Navy and the United States Coast Guard, with special Public Health Service Commissioned Corps insignia, and hold naval ranks equivalent to officers of the Navy and Coast Guard, along with corresponding in-service medical titles. Commissioned corps officers typically receive their commissions through the commissioned corps's direct commissioning program.

In the United States Navy, United States Coast Guard, United States Public Health Service Commissioned Corps (USPHS Corps), and National Oceanic and Atmospheric Administration Commissioned Officer Corps (NOAA Corps), captain is the senior-most commissioned officer rank below that of flag officer (i.e., admirals). The equivalent rank is colonel in the United States Army, Air Force, Space Force, and Marine Corps.

Reflecting its nautical heritage, the term captain is used as a military title by officers of more junior rank who command a commissioned vessel of the Navy, Coast Guard, or National Oceanic and Atmospheric Administration (NOAA) of patrol boat size or greater. Officers below O-6 who command aviation squadrons (typically O-5 commanders) usually use the less formal title "skipper".

Pay grades are used by the eight structurally organized uniformed services of the United States (Army, Marine Corps, Navy, Air Force, Space Force, Coast Guard, Public Health Service Commissioned Corps, and NOAA Commissioned Officer Corps), as well as the Maritime Service, to determine wages and benefits based on the corresponding military rank of a member of the services. While different ranks may be used among the eight uniformed services, pay grades are uniform and equivalent between the services and can be used to quickly determine seniority among a group of members from different services. They are also essential when determining a member's entitlements such as basic pay and allowances.

A squadron in an air force, or naval or army aviation service, is a unit comprising a number of military aircraft and their aircrews, usually of the same type, typically with 12 to 24 aircraft, sometimes divided into three or four flights, depending on aircraft type and air force.

In most armed forces, two or more squadrons will form a group or a wing. Some military forces (including the United States Air Force, United States Space Force, French Air and Space Force, Royal Air Force, German Air Force, Royal Netherlands Air Force, Belgian Air Component and Republic of Singapore Air Force) also use the term "squadron" for non-flying ground units (e.g. radar squadrons, missile squadrons, air defense squadrons, aircraft maintenance squadrons, security forces squadrons, civil engineering squadrons, range operations squadrons, range management squadrons, weather squadrons, medical squadrons, etc.).

Greenland is divided into five municipalities and two unincorporated areas. The municipalities are Avannaata, Kujalleq, Qeqertalik, Qeqqata, and Sermersooq. Northeast Greenland National Park is a huge unincorporated area that is outside the municipalities and larger than any of them. Pituffik Space Base is a small unincorporated enclave surrounded by the Avannaata municipality and administered by the United States Space Force.

The United States secretary of defense (SecDef), secondarily titled the secretary of war (SecWar), is the head of the United States Department of Defense (DoD), the executive department of the U.S. Armed Forces, and is a high-ranking member of the cabinet of the United States. The secretary of defense's position of command and authority over the military is second only to that of the president of the United States, who is the commander-in-chief. This position corresponds to what is generally known as a defense minister in many other countries. The president appoints the secretary of defense with the advice and consent of the Senate, and is by custom a member of the Cabinet and by law a member of the National Security Council.

Subject only to the orders of the president, the secretary of defense is in the chain of command and exercises command and control, for both operational and administrative purposes, over all DoD-administered service branches  – the Army, Marine Corps, Navy, Air Force, and Space Force – as well as the Coast Guard when its command and control is transferred to the Department of Defense. Only the secretary of defense (or the president or Congress) can authorize the transfer of operational control of forces between the three military departments (Department of the Army, the Navy, and the Air Force) and the eleven Unified Combatant Commands.

In the United States Armed Forces, a lieutenant general is a three-star general officer in the United States Army, Marine Corps, Air Force, and Space Force.

A lieutenant general ranks above a major general and below a general. It is abbreviated as LTG in the Army, LtGen in the Marine Corps, and Lt Gen in the Air Force and Space Force and is equivalent to the rank of vice admiral in the United States uniformed services that use naval ranks. The pay grade of lieutenant general is O-9.
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The secretary of the Air Force, sometimes referred to as the secretary of the Department of the Air Force, (SecAF, or SAF/OS) is the head of the Department of the Air Force and the service secretary for the United States Air Force and United States Space Force. The secretary of the Air Force is a civilian appointed by the president, by and with the advice and consent of the Senate. The secretary reports to the secretary of defense and/or the deputy secretary of defense, and is by statute responsible for and has the authority to conduct all the affairs of the Department of the Air Force.

The secretary works closely with their civilian deputy, the under secretary of the Air Force; and their military deputies, the chief of staff of the Air Force and the chief of space operations.

Space Force Combat Forces Command is the United States Space Force's space operations, cyber operations, and intelligence field command. Headquartered at Peterson Space Force Base in Colorado Springs, Colorado, it consists of its mission deltas and garrison commands.

It was established on 1 September 1982 as Space Command (SPACECOM), the first dedicated U.S. space command. On 15 November 1985, it was renamed Air Force Space Command (AFSPC or AFSPACECOM) to distinguish it from U.S. Space Command, Naval Space Command, and Army Space Command. On 20 December 2019, after the establishment of the United States Space Force as an independent service, Air Force Space Command was redesignated as United States Space Force (USSF) and served as the transitional headquarters of the new service, but remained a component of the U.S. Air Force. On 21 October 2020, United States Space Force was redesignated as Space Operations Command and officially transitioned from being a U.S. Air Force major command to a U.S. Space Force field command.

Civil control of the military is a doctrine in military and political science that places ultimate responsibility for a country's strategic decision-making in the hands of the state's civil authority, rather than completely with professional military leadership itself. As such, a "fundamental requirement of any nation is to ensure that the activities of its armed forces be subordinated to the political purposes of constitutional government; hence, the armed forces must be under civil control". The concept of civil control falls within the overarching concept of civil-military relations representing the "societal imperative that the military remain subordinate to civil authority and that it reflect, to an appropriate degree, societal values and norms".

Civil oversight over militaries puts the power to take military action in the hands of a civil authority, such as through government ministers or legislative bodies, or the democratic apparatus of the Crown in constitutional monarchies. Allowing the civil component of government to retain control over the military or state security illustrates the power of the citizenry, a healthy respect for democratic values, and what can be described as good governance. Giving power to the civil component of the government over what the military can do and how much money it can spend protects the democratic process from abuse. Nations that can achieve legitimate relationship between the two structures serve to be more effective and provide accountability between government and military.