the afternoon of December 3rd, 2018, a SpaceX Falcon 9 rocket took off from the southern coast of California, lofting the largest haul of individual satellites the vehicle had ever transported. At the time, it seemed like the mission was a slam dunk, with all 64 satellites deploying into space as designed.
But nearly four months later, more than a dozen satellites from the launch have yet to be identified in space. We know that they’re up there, and where they are, but it’s unclear which satellites belong to which satellite operator on the ground.
They are, truly, unidentified flying objects.
The launch, called the SSO-A SmallSat Express, sent those small satellites into orbit for various countries, commercial companies, schools, and research organizations. Currently, all of the satellites are being tracked by the US Air Force’s Space Surveillance Network — an array of telescopes and radars throughout the globe responsible for keeping tabs on as many objects in orbit as possible. Yet 19 of those satellites are still unidentified in the Air Force’s orbital catalog. Many of the satellite operators do not know which of these 19 probes are theirs exactly, and the Air Force can’t figure it out either.
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Not knowing the exact location of a spacecraft is a major problem for operators. If they can’t communicate with their satellite, the company’s orbiting hardware becomes, essentially, space junk. It brings up liability and transparency concerns, too. If an unidentified satellite runs into something else in space, it’s hard to know who is to blame, making space less safe — and less understood — for everyone. That’s why analysts and space trackers say both technical and regulatory changes need to be made to our current tracking system so that we know who owns every satellite that’s speeding around the Earth. “The whole way we do things is just no longer up to the task,” Jonathan McDowell, an astrophysicist at Harvard and spaceflight tracker, tells The Verge.
How to identify a satellite
until recently, figuring out a satellite’s identity has been relatively straightforward. The Air Force has satellites high above the Earth that detect the heat of rocket engines igniting on the ground, indicating when a vehicle has taken off. It’s a system that was originally put in place to locate the launch of a potential missile, but it’s also worked well for spotting rockets launching to orbit. And for most of spaceflight history, usually just one large satellite or spacecraft has gone up on a launch — simplifying the identification process.
“For more traditional launches, where there are fewer objects, it’s fairly simple to do,” Diana McKissock, the lead for space situational awareness sharing and spaceflight safety at the Air Force’s 18th Space Control Squadron, tells The Verge. As a result, the Air Force has maintained a robust catalog of more than 20,000 space objects in orbit, many of which have been identified.
But as rocket ride-shares have grown in popularity, the Air Force’s surveillance capabilities have sometimes struggled to identify every satellite that is deployed during a launch. One problem is that most of the spacecraft on board all look the same. Nearly 50 satellites on the SSO-A launch were modified CubeSats — a type of standardized satellite that’s roughly the size of a cereal box. That means they are all about the same size and have the same general boxy shape. Plus, these tiny satellites are often deployed relatively close together on ride-share launches, one right after the other. The result is a big swarm of nearly identical spacecraft that are difficult to tell apart from the ground below.
Operators often rely on tracking data from the Air Force to find their satellites, so if the military cannot tell a significant fraction of these CubeSats apart, the operators don’t know where to point their ground communication equipment to get in contact with their spacecraft.
It’s a bit of a Catch-22, though. The Air Force also relies on satellite operators to help identify their spacecraft. Before a launch, the Air Force collects information from satellite operators about the design of the spacecraft and where it’s going to go. The operators are also responsible for making sure that they have the proper equipment (in space and on the ground) to communicate with the satellite. “It’s really a cooperative, ongoing process that involves the satellite operators as much as it involves us here at the 18th, processing the data,” says McKissock.
SSO-A launch isn’t the only example of mistaken satellite identity. Five satellites are still unidentified from an Electron launch that took place in December last year, which sent up 13 objects, according to McDowell. And in 2017, a Russian Soyuz rocket deployed a total of 72 satellites, but eight are still unknown, says McDowell. The SSO-A launch is perhaps the most egregious example of this ride-share problem, as nearly a third of the satellites are still missing in the Air Force’s catalog.
The Air Force says the launch posed a unique challenge. One difficulty had to do with the way the satellites were deployed, according to McKissock, who says it was hard to predict before the launch where each satellite was going to be. The SSO-A launch was organized by a company called Spaceflight Industries, which acts as a broker for operators — finding room for their satellites on upcoming rocket launches. Spaceflight bought this entire Falcon 9 rocket for the SSO-A launch, and created the device that deployed all of these satellites into orbit. One satellite tracker, T.S. Kelso, who operates a tracking site called CelesTrak, agreed with the Air Force, saying that Spaceflight’s deployment platform made it hard to predict each satellite’s exact position. “[Spaceflight] had no way to provide the type of data needed,” Kelso writes in an email to The Verge.
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The Air Force’s 18th Space Control Squadron has other priorities to consider, too. While identifying spacecraft is something the team always hopes to accomplish on every flight, the main function of the 18th is to track as many objects as possible and then provide information on the possibility of spacecraft running into each other in orbit. The identification of satellites is secondary to that safety concern. “I wouldn’t say it’s not a priority, but we certainly have other mission requirements to consider,” says McKissock.
Source: Unidentified satellites reveal the need for better space tracking – The Verge
Robin Edgar
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