The U.S. Air Force’s supersecret X-37B was launched into orbit for the fourth time last week, and amateur satellite watchers have promptly identified its secret orbit—also for the fourth time. There is, you see, a small army of amateurs who keep track of over 300 spy satellites, often with little more than a pair of binoculars.


The orbit of the X-37B, which resembles a mini space shuttle, was revealed on a hobbyist satellite watcher mailing list today. According to longtime satellite observer Ted Molczan interviewed Spaceflight Now, the plane is flying lower than in previous missions, and it is surveying the same region on the ground every two days—a frequency that could indicate some kind of spy mission. The government has revealed two experiments onboard X-37B but has, as always, kept mum about everything else.

Molczan and other members of an amateur satellite observing group found the secret orbit of the first X-37B back in 2010, too. It took a few weeks and independent observations in North America and South Africa. He later characterized the discovery as “sort of a fluke.” But with three X-37Bs under their belt, the group knew what to expect with the fourth mission. A couple days before the space plane blasted off, Molzcan posted an email to the SeeSat email list with orbit estimates. Today, a week after launch, an email to the group announced the X-37B’s orbit.


More Secret Satellites

Among satellite watchers, Molczan is perhaps best known for identifying USA-193, a secret spy satellite that failed soon after orbit in 2006. The U.S. intentionally destroyed it with a missile 18 months later—prompting all sorts of controversy over the exact purpose of the satellite.

The hobby of these amateur satellite watchers has, not surprisingly, prompted some concern from the intelligence community. “If we had our druthers, we would prefer that these things not end up on the Internet,” says Rick Oborn, an NRO spokesperson told Wired in 2006. “It’s no secret that other countries stop doing what they’re doing when the satellites are overhead.”

But the reality is, tracking even these stealth satellites is not that hard. Here’s how the New York Times described Molzcan’s setup at his Toronto apartment, which uses just a pair of binoculars, star charts, and a stopwatch.

From his 23rd-floor balcony, or the roof of his 32-floor building, Mr. Molzcan will peer through his binoculars at a point in the sky he expects the satellite to cross, which he locates with star charts. When the moving dot appears, he determines its direction and the distance it travels across the patch of sky over time, which he can use to calculate its speed.


If a guy from his balcony can track these satellites, goes the reasoning, so can China—and so can any country with even the most marginal astronomy knowledge. Perhaps that’s what so fascinating of all. The U.S. will go to great lengths to obscure the nature of its spy satellites, but space is empty. Space is transparent. Satellites have nowhere to hide.

[Spaceflight Now, New York Times, New York Times, Wired, Boing Boing]

The post has been updated to reflect the plane’s orbit was first revealed on the SeeSat listserv.


Contact the author at sarah@gizmodo.com .