The U.S. Space Force operates and protects the military satellites used across the American armed forces. Established on December 20, 2019, it is the sixth branch of the U.S. military and sits within the Department of the Air Force, much like the Marine Corps sits within the Department of the Navy. Its members are known as Guardians, and despite the name, almost all of their work takes place on Earth, from operations centers and radar sites to launch pads.
What the Space Force Does Day to Day
The Space Force has five core jobs, and each one keeps a system working that troops on the ground, at sea, or in the air already depend on. The branch is small and specialized, so it does a narrow set of things very deliberately.
- Space domain awareness. Guardians track thousands of objects in orbit so commanders know what is a working satellite, what is debris, and what might be a threat.
- Satellite operations. Crews keep navigation, missile-warning, and communications satellites healthy so a soldier’s map still works and a missile launch still gets spotted.
- Launch and space access. The branch gets new satellites safely to orbit so replacement and upgrade capacity is always available.
- Protecting American assets in orbit. Units guard satellites against jamming and attack so the signals stay up when a rival tries to knock them down.
- Electronic warfare. Guardians defend the radio links between satellites and the ground so an adversary cannot cut off or fake the data.
Space Domain Awareness: Watching Orbit
Space domain awareness means knowing where every satellite, spent rocket body, and fragment of debris is, and where each one is heading next. Low Earth orbit now holds tens of thousands of tracked objects moving faster than 17,000 miles per hour. A collision at that speed can destroy a working satellite and scatter thousands of new fragments. The Space Force runs a global network of radars and telescopes that watches these objects and predicts close approaches. Much of that catalog is shared publicly through Space-Track.org, which satellite operators around the world use to avoid collisions.
Running GPS, Missile Warning, and Satellite Communications
Guardians fly the satellite fleets that deliver navigation, early warning, and secure communications. The Global Positioning System (GPS) is the clearest example. Space Force crews keep the GPS constellation healthy so the timing and location signals stay accurate, and those same signals sync power grids, stock trades, and phone networks far beyond the military. You can read how the civil side of the system works on the government’s own GPS.gov reference.
Missile-warning satellites carry infrared sensors that detect the heat of a rocket launch within seconds. That early warning gives leaders time to react and gives defense systems a chance to respond. Satellite communications, or SATCOM, keep commanders connected to units in places with no cell towers and no fiber, such as the middle of an ocean or a remote mountain range.
The GPS constellation itself is explained in our guide to how GPS works.
Getting Satellites to Orbit
The Space Force manages America’s military launch ranges and licenses the flights that carry national-security payloads. Most launches lift off from Cape Canaveral in Florida or Vandenberg in California, where Space Force units clear the airspace, track the rocket, and certify that it can carry sensitive cargo. The branch buys most of its rides from commercial companies rather than building its own rockets, working with providers such as SpaceX and United Launch Alliance. That approach lets the Space Force replace an aging satellite without maintaining a rocket factory of its own.
Defending Satellites and Their Signals
Satellites are hard to reach but easy to disrupt, so a large part of the mission is protection. Rivals can jam a signal, spoof a false one, blind a sensor with a laser, or maneuver another object dangerously close. Space Force units watch for these moves and train to keep a satellite useful even while someone tries to interfere with it. The point is not to fight battles in orbit. The point is to make sure a jammed GPS signal or a blocked communications link does not leave troops on the ground without the data they came to expect.
The jammers, surveillance satellites, and on-orbit weapons the service has acknowledged are itemized in our Space Force weapons inventory.
How the Space Force Is Organized
The Space Force runs its mission through three field commands, each owning a distinct slice of the work. Space Operations Command (SpOC) provides the crews and units that fly satellites and staff the operations centers around the clock. Space Systems Command (SSC) buys, builds, and launches the systems, managing the contracts with the commercial rocket and satellite makers the branch depends on. Space Training and Readiness Command (STARCOM) trains new Guardians and develops the tactics they use in the field. Splitting operating, buying, and training into separate commands lets a small branch keep each function focused rather than stretching every unit across all three. At the top, the Chief of Space Operations leads the branch from the Pentagon, reports through the Secretary of the Air Force, and sits on the Joint Chiefs of Staff alongside the heads of the other services. The branch organizes, trains, and equips its Guardians, and U.S. Space Command is the separate joint command that directs them on operations.
The acquisition arm that buys the satellites and launches is profiled in our Space Systems Command explainer.
What it costs to run all of this, year by year, is covered in our Space Force budget explainer.
What the Space Force Does Not Do
The Space Force is not the science-fiction picture many people carry into the search. It has no space marines, no orbital fighter craft, and no Guardians stationed on the Moon. The branch does not fly astronauts, run the civil space program, or explore the solar system. Human spaceflight, planetary science, and the space telescopes belong to NASA, a civilian agency with a completely separate budget and chain of command. The Space Force is also the smallest U.S. military branch by a wide margin, and most Guardians spend their day at a console, a radar screen, or a launch console rather than in a spacesuit. Understanding that gap between the movie version and the desk version is the fastest way to understand the branch.
Space Force vs NASA: Two Different Space Agencies
People confuse the Space Force with NASA more than any other question, so it helps to line them up directly.
| Question | U.S. Space Force | NASA |
|---|---|---|
| Main purpose | Defend U.S. interests in space, run military satellites | Science, exploration, human spaceflight |
| Who works there | Military Guardians and civilian staff | Civilian scientists, engineers, and astronauts |
| Sends people to orbit | No | Yes |
| Part of the military | Yes, the sixth branch | No, a civilian agency |
| Reports to | Department of the Air Force | The White House, as an independent agency |
The short version: NASA is about reaching space, and the Space Force is about protecting what the country already uses there.
To see how Guardians are ranked from recruit to four-star general, read the guide to Space Force ranks. For where Guardians actually work, see the roster of Space Force bases. To learn how people actually join and what the careers look like, see Space Force jobs and what the Space Force does for the members who fill those roles.
For the branch-to-branch comparison instead, see our Space Force vs Air Force page.