The United Nations Space Command Navy, often shortened to the UNSC Navy and commonly referred to as The Navy by humans, is the space faring naval warfare service branch of the United Nations Space Command Defence Force and one of the nine uniformed services. It is the third largest Naval force in the Orion Spur and the ninetieth largest in known space by tonnage. The Navy has almost two hundred and fifty million personnel on active duty and another seventy million in the Naval Reserves. It operates over two hundred and eighty thousand vessels in active duty and almost one million vacuum-rated starfighters.