Satellite missing since ’90s found in Earth’s orbit. How does one lose a satellite?

Have you ever misplaced your keys for a few days and felt the frustration? Now imagine losing a satellite for a whopping 25 years! That’s exactly what happened with the S73-7 satellite, which has just recently been spotted, turning its story into something akin to a cosmic mystery novel.

**Lost in Space**
Launched in 1974, the S73-7 satellite mysteriously disappeared in the 1990s, blending into the vast expanse of space debris that orbits Earth. It evaded detection for decades until it made a sudden reappearance on radar screens this week, rediscovered by the Space Force’s 18th Space Defence Squadron.

Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, excitedly shared on X (formerly Twitter), “The S73-7 satellite has been rediscovered after being untracked for 25 years.”

**How Do You Lose a Satellite?**
Known as the Infra-Red Calibration Balloon, this satellite was part of a United States Air Force Space Test Program. Its mission was to inflate in orbit and act as a calibration target for remote sensing instruments. Unfortunately, it drifted into obscurity due to a deployment failure shortly after its launch on April 10, 1974.

According to Gizmodo, satellites and debris often disappear for years amid the crowded orbits around Earth. McDowell explained that the S73-7 was tracked initially in the 1970s but vanished in the 1990s. He suggested that the object they’re tracking might be a dispenser or a piece of the balloon that didn’t deploy correctly, noting it has a “very low radar cross-section” and might not be metal, making it difficult to detect on radar.

Ground-based radar and optical stations constantly monitor over 20,000 objects in orbit, a challenging task since most don’t broadcast their locations. Tracking involves matching known orbits, a process complicated by geostationary orbits where tracking gaps occur. McDowell likened it to air traffic control, emphasizing the importance of knowing where potential hazards are in the crowded skies above.

“This rediscovery underscores the challenges of monitoring the 27,000 objects in Earth’s orbit, from active satellites to space debris,” he added.