VANDENBERG AIR FORCE BASE, Calif. (AFNS) -- While the everyday activities of life continue down below, what is taking place overhead doesn’t usually warrant a thought.
The 18th Space Control Squadron located at Vandenberg Air Force Base, California, is a geographically separated unit of the 21st Space Wing, Peterson AFB, Colorado. The squadron provides situational awareness on thousands of items filling the skies while life moves along for those on Earth’s surface.
“We have crews of eight people,” said 1st Lt. Jonathan Diaz, an 18th SPCS mission commander. “We have Orbital Safety Analysts who are direct liaisons to National Aeronautics and Space Administration whose main concern is the (International Space Station) and astronauts. We have people supporting conjunction assessment who notify the satellite owner if anything approaches their (satellite), or is going to fly close by, so they can move it if they want. Others keep the Satellite Catalog up to date.”
Space operators monitor space to gain situational awareness on more than 1,300 satellites, the International Space Station and other items often known as debris.
Objects entering or exiting space are observed and data is collected for analysis from a worldwide network of sensors. The station is closely tracked to monitor approaching obstacles that could pose a problem. Potential collisions between satellites are scrutinized. The Airmen of the 18th SPCS carefully catalog all this orbital data to provide situational awareness in the space domain.
The catalog is a record of everything within Earth’s orbit at any given time. The vital characteristics of the object, as well as its orbit also are tracked.
“We catalog what the object is and where it is going,” Diaz said. “We monitor launches and assign a number so we can track them.”
If an object moves, or in some way changes its course, the crews of the 18th SPCS notify several different organizations, especially if the object is owned by another country. They notify every area of responsibility within the Defense Department, Peterson AFB, Defense Special Missile & Astronautics Center, Wright Patterson AFB, Ohio, Federal Emergency Management Agency, and the entire Space Surveillance Network, Diaz said. Allied countries are notified as well.
“We notify everyone around the globe,” he said. “We post new two-line element sets and the reentry information to Spacetrack.org. Anyone in the world can create an account if they wish.”
A two-line element is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time.
Monitoring what is in space is critical, but monitoring what is leaving space is equally important. The squadron monitors and provides analysis on items re-entering Earth’s atmosphere. Diaz said they determine where an object is falling and then depending upon that information, alert the proper agencies.
“The on-duty mission commander will post periodic blogs on required runs for reentries once they're under 24 hours out, Diaz said. “Most people that read these blogs are from the Missile Warning Center, Missile Defense Agency, (U.S. Strategic Command), and other agencies.”
The blogs are posted at intervals of one day, 12 hour, six hour, two hour, and final run. Entries are posted to the Strategic Knowledge Integration Web, part of the Defense Information Systems Agency website.
A typical day for them is hard to describe, because there are so many variables in play guiding the crew’s focus, Diaz explained. One typical event, however, is a space launch. Launches made from the U.S. are easier for crews to plan ahead of time because they have all the information for cataloging the event. It can be complicated if the launch is made by a foreign country because all of the information is not provided.
“We have a couple of conjunctions on a typical day,” said Diaz. “So we make sure there aren’t any collisions. Maybe we have a launch to process and catalog, maybe a re-entry. The one thing we do constantly is make sure the (satellite) catalog is up to date.”
“The ops tempo we experience fluctuates drastically and is most closely correlated with the space launch calendar,” said Capt. Christopher Fabian, an 18th SPCS mission commander. “Tracking and cataloging new space objects then ensuring timely, accurate information to relevant agencies is a time intensive and involved process.”
Obtaining robust initial information is essential for maintaining an accurate satellite catalog, Fabian said. Once an object is cataloged, on-orbit conjunction analysis can be performed. Conjunction analysis involves screening for dangerous approaches between space objects, then providing actionable data to owner and/or operators they can use to perform collision avoidance actions.
Generating and disseminating all the data can be extremely time-consuming if more than a typical number of conjunctions are detected. Fabian said the crews also ensure safe passage of the International Space Station, performing conjunction screenings between the station and other objects passing through its orbit.
“Similar to the on-orbit conjunction analysis, this can create a heavy workload,” he said. “Aside from general event processing and daily procedures, a major part of the job is up-channeling space situational awareness information to Air Force leadership.”
For the person sitting in rush hour traffic on a busy highway, what is going on overhead might not come to mind. But rest assured, the operators at the 18th SPCS are keeping watch on objects along the highways of space.