Cosmos 1220 spy satellite safely burns up in atmosphere

Amateur video of Cosmos 1220 burning up over Saudi Arabia during re-entry Sunday

The Russian military reconnaissance satellite launched in 1980 and designed to spy on enemy naval forces met a fiery end Sunday morning when it re-entered Earth’s atmosphere around 8 a.m. CST. This according to Russian defence ministry spokesman Colonel Dmitry Zenin.

Because Cosmos 1220 was an older satellite with no protocols set up to pilot it to a safe fall over an ocean, there was some concern that any debris surviving re-entry might crash down over inhabited lands. While I haven’t heard exactly where it came down and whether any pieces have been found, there have been no reports of injuries out of Saudi Arabia or anywhere else connected to machines falling out of the sky.

The most recent large satellite to de-orbit and burn up was the European Gravity Ocean Circulation Explorer (GOCE) on November 10, 2013. It disintegrated in the South Atlantic Ocean near the Falkland Islands.

A satellite falling on your head is a scary thought until you consider the broader context. Heiner Klinkrad, head of the ESA’s Space Debris Office at the time of GOCE’s descent put it this way: “In the 56 years of spaceflight, some 15,000 tonnes of man-made space objects have re-entered the atmosphere without causing a single human injury to date.”

The night the Cosmos fell to Earth

One of Russia’s Cosmos satellites (there are many in a series). Cosmos 1484 gathered data on natural resources from orbit.

Last night around 9:30 p.m. Eastern time, hundreds of residents living along the East Coast of the U.S. were treated to a spectacular, slow-moving, long-lived meteor about as bright as the full moon. But there was something different about this meteor – it was man-made.

To get a feeling for what most of us missed, check out the American Meteor Society’s fireball reporting site. As of this afternoon, over 30 reports from 8 different states have been received that correlate with the time and path of the Russian Cosmos 1484 reconnaissance satellite which was expected to re-enter the atmosphere around that time. The U.S. Strategic Command reported the re-entry or “decay” (in satellite lingo) at 9:38 p.m. EST +/- 17 minutes.

Short video of Cosmos 1484 crossing in front of the moon taken by an amateur astronomer

Cosmos 1484 was launched from Russia’s Baikonur cosmodrome in 1983, the same place Yuri Gagarin, the first human to orbit the Earth, lifted off on April 12, 1961. The Cosmos probe was classified as a “remote sensing” satellite, another way of saying it studied its subject without touching it – from orbit. Using cameras, radar and other sensors, Cosmos gathered information on natural resources like forests, cropland, lakes and seas for use by the-then Soviet Union in planning its economy.

When the sample capsule from the Japanese Hayabusa spacecraft entered Earth’s atmosphere in June 13, 2010, it created a spectacular fireball. The capsule, containing particles from the asteroid Itokawa, landed safely. Click for awesome video. Credit: Takashi-Ozaki, Yomiuri Simbun, AP

Over time, the orbit of 5,500-lb. Cosmos 1484 “decayed” due to the inevitable drag of air molecules. While there aren’t many of them at typical low Earth-orbit altitudes, their effect accumulates and accelerates over time.

Even at 250 miles high, the International Space Station needs to periodically fire its engines to boost its altitude from time to time. Some newer satellites have rockets and controls to counter atmospheric drag and maintain a preferred orbit. Many others, especially the older ones like Cosmos 1484, either don’t or have run out of fuel.

Air drag lowers a satellite’s orbit, which causes it to speed up, which further increases drag, which speeds it up even more in an ever-spiraling process until the satellite finally re-enters the atmosphere in a ball of fire. Satellite re-entry speeds are normally much slower than the cosmic speed of meteors – those bits of asteroid and comet dust – so they take their time crossing the sky as they put on a fiery show.

One of Skylab’s air tanks that made it through re-entry and crashed to the ground. It’s on display at US Space and Rocket Center, Huntsville, Alabama. Credit: Wikipedia

A falling satellite – that’s what you lucky East Coasters saw last night. I’ve only heard of one report of fragments picked up by Doppler weather radar possibly in Georgia. Most satellites completely burn up upon re-entry, but sometimes pieces survive. One notable example was the plunge of NASA’s Skylab Space Station when it re-entered over Australia near Perth on July 11, 1979. After a mouth-dropping show of satellite-frying fireworks, at least two dozen pieces were picked up.

If you’re interested in what satellites will be dropping back to Earth in the near-future, click over to Satview’s Reentry site.