The U.S. Space Force (USSF) is a new branch of the Armed Forces. It was established on December 20, 2019 with enactment of the Fiscal Year 2020 National Defense Authorization Act and will be stood-up over the next 18 months. The USSF was established within the Department of the Air Force, meaning the Secretary of the Air Force has overall responsibility for the USSF, under the guidance and direction of the Secretary of Defense. Additionally, a four-star general known as the Chief of Space Operations (CSO) serves as the senior military member of the USSF. The CSO is a full member of the Joint Chiefs of Staff. Mission The USSF is a military service that organizes, trains, and equips space forces in order to protect U.S. and allied interests in space and to provide space capabilities to the joint force. USSF responsibilities include developing military space professionals, acquiring military space systems, maturing the military doctrine for space power, and organizing space forces to present to our Combatant Commands. Office of the Chief of Space Operations The Chief of Space Operations, U.S. Space Force, serves as the principal uniformed adviser to the Secretary of the Air Force on Space Force activities. The CSO presides over the Office of the Chief of Space Operations, transmits plans and recommendations to the Secretary of the Air Force and acts as the Secretary's agent in carrying them out. Space Force Organization The USSF Headquarters and Office of the CSO are located in the Pentagon, just like the Army, Navy, Marine Corps, and Air Force. This staff will focus on establishing a fully-functioning headquarters; preparing to execute the full scope of its organize, train, and equip responsibilities; and, in conjunction with the U.S. Air Force, developing a detailed plan to transfer forces into the U.S. Space Force. As a new military service, the U.S. Space Force will leverage the Department of the Air Force for more than 75 % of its enabling functions.