In 2016 a Navy satellite called MUOS-5 wasn't doing well. Partway to its intended orbit, it simply stalled out — but because the spacecraft was already so far away, the dilemma's details were hard to discern. That's where the Geosynchronous Space Situational Awareness Program came in: GSSAP satellites can sidle up to and take pictures of other orbiters, beaming the portraits back to Earth. So from Schriever Air Force Base in Colorado, operators maneuvered the agile GSSAP satellite close to the inert MUOS-5 to inspect it. Although we don't know exactly how GSSAP's data helped, MUOS-5 zipped up to its orbit a few months later.
This zoom-in approach is GSSAP's special power — for helping U.S. satellites and spying on foreign ones. According to data for a report from the Secure World Foundation, a space-centric think tank, the GSSAP satellites had close encounters with eight international orbiters between 2016 and mid-2018.
The satellites' primary job, though, is actually to watch others from a safe distance, keep tabs on space traffic and ensure things are flowing smoothly, securely. They also keep track of the space junk that can slam into and damage said satellites.
Right now four GSSAP satellites are in orbit, with two more launching this year. They're part of an increasingly intense stare at the space beyond low-Earth orbit: from geosynchronous orbit, or GEO, out to the Moon.
The satellites out there because they provide things like communication and have become necessary to the way the world turns. And during the Covid-19 pandemic, tracking and protecting them — from accidental crash or purposeful meddling — has grown even more critical than usual. "During times of crisis, timely communication, much of which is reliant on space, is of utmost importance," says Diana McKissock of the Space Force's 18th Space Control Squadron, which tracks and catalogs satellites.
As commercial traffic escalates, officials worry about political conflict in deep space. Programs like GSSAP aim to ensure that all systems are on track.
And GSSAP isn't alone: Back on the ground, agencies like the Intelligence Advanced Research Projects Activity — the intelligence community's DARPA doppelganger — hope to create optical telescopes so powerful they can take geosynchronous pictures from Earth. That's useful when GSSAP satellites aren't conveniently close to the shot you'd like to take.
"Just because your satellite is in GEO doesn't mean it can immediately toodle over to the right part of GEO," says Jonathan McDowell of Harvard-Smithsonian's Center for Astrophysics, who publishes catalogs of space launches, satellite orbits and their reentries into the atmosphere. "Plus, you might not always want [another country] to know you're peeping at their goods, which they absolutely would if you toodled over."
"There's always been a sensitivity about going up next to other satellites and spying on them," says McDowell.
The Space Force's 18th Space Control Squadron also tracks and catalogs far-out satellites from both the ground and space. Lots of communications equipment live in GEO, says the squadron's McKissock. "They're critical to the things we enjoy on Earth," she says.
Certain "assets" up there are also critical to the American defense and intelligence communities. And keeping them in good working order is more complicated than it used to be: There's more debris; private industry has hugely increased the number of active satellites, so the number of potential collisions, and actual country-on-country threats, exist.
"It's not the benign environment that it was when I started this job in 2010," says McKissock. To keep track of the action, the unit uses data from satellites, like the ORS-5; turns on ground-based radar; and points planet-planted telescopes toward orbit. Recently, it spooled up the so-called Space Fence, a powerful radar system that tracks not just GEO satellites but also the smaller pieces of debris many thousands of miles from Earth.
However, a new organization, called the Space Development Agency, has its gaze focused even farther out: on everything between geosynchronous orbit and the Moon. "Most of the investment in space architecture has been at lower altitudes," says Jerry Krassner, a space expert currently supporting the SDA. But more corporations, and countries, are making plans for more distant projects. "One of the things SDA is doing is getting out in front of that emerging threat and attempting to deter hostile action," says Krassner. The first aspect of that deterrence: just watching, and letting people know it.
As part of that, the SDA has proposed a fleet of sentry spaceships. Far beyond Earth, they'd snooze until sensors indicate a problem nearby — like one satellite edging too close to another. Then, jolted awake, they could go take a picture of the problem, like a bystander filming a crime on their cellphone. That picture would wend its way to an important person's computer. That person, perhaps the president, could call the responsible country, show them the shot, and say, "Please cut it out."
That "gotcha" ability, the thinking goes, helps prevent bad acting in the first place: If, for example, you know a cookie jar has a camera with facial-recognition software on the lid, you'd probably leave it alone.
Such steely-eyed satellite action represents a big change from the start of space surveillance, which focused on weapons detection and on the lower altitudes where missiles might tread. "The high-orbit stuff was not that interesting, because they obviously weren't missiles," says McDowell of Harvard-Smithsonian's Center for Astrophysics.
That "not interesting" attitude may have fossilized and stayed a little longer than it should have. Till now-ish. "They've sort of woken up," McDowell notes, "and said, 'We have to be serious about this.'"