Splashdown! Falling GOCE satellite lands in the Atlantic

GOCE, the gravity-measuring satellite launched by the European Space Agency, has splashed down after reentering Earth's atmosphere above the Falkland Islands.

Google Maps / ESA
When GOCE ran out of xenon, it began a three-week descent, ultimately splashing down in the Atlantic Ocean Sunday night. It entered the atmospheric no later than 7:16 p.m. EST, Nov. 10, say officials, near the red A off the coast of South America. GOCE debris therefore would have fallen into the southernmost regions of the Atlantic Ocean.

After fighting a losing battle against gravity, the European Space Agency's GOCE satellite has made splashdown somewhere in the south Atlantic Ocean, says the ESA. Its final orbit flew over Siberia, the western Pacific Ocean, the eastern Indian Ocean, and Antarctica before entering the atmosphere a few hundred miles south of the Falkland Islands.

As expected, the 2,500-pound satellite broke apart when it reentered the atmosphere, about 80 miles above Earth's surface. The ESA estimates that three-fourths of the satellite burned up during reentry, leaving some 600 pounds of material, probably broken into several dozen pieces, to splash into the Atlantic.

An ocean splashdown was always most likely, as 70 percent of Earth's surface is covered in water.

GOCE reentered the atmosphere no later than 7:16 p.m. Eastern time, Sunday evening, say officials with the US Space Control and Space Surveillance (SCSS). GOCE debris therefore would have fallen into the southernmost regions of the Atlantic Ocean, reports Daniel Scuka, senior editor for spacecraft operations at ESA's European Space Operations Centre in Darmstadt, Germany.

GOCE, the Gravity field and Ocean Circulation Explorer, was launched in March 2009 to map Earth's gravity, in hopes of better understanding ocean currents and the Earth's interior. In order to detect subtle changes in Earth's gravitational field, GOCE had a very low orbit – so low that it felt drag from the edge of Earth's atmosphere, known as the exosphere. To achieve a smooth flight, GOCE used an electric ion propulsion system, pushing electrically charged xenon out the "back" of the satellite to create a gentle forward thrust.

The mission ended Oct. 21, when the satellite had too little xenon gas to continue its propulsion system. It ran completely out of xenon three days later, on Oct. 24. The satellite fell first slowly, then more and more quickly, from a descent of about 1 mile per day at first, to more than 1 mile per hour on its last day in space, ultimately making splashdown at terminal velocity, about 200 m.p.h.

GOCE lasted almost three times as long as expected: Despite an original mission timeline of 20 months, GOCE flew about 4.5 years. Both sturdy and sleek, the satellite known as the "Ferrari of space" stayed strong to the end, holding together through reentry much longer than scientists had anticipated, even as its central computer temperature rose to more than 170 degrees Fahrenheit. The reentry data gathered by ground-based scientists will be invaluable in helping scientists predict future space debris descents.

GOCE was just one of the more than 3,000 satellites in orbit, of which about 1,000 are still operational, according to the ESA. SCSS tracks more than 22,000 large space objects, and NASA is aware of millions of small objects. When their orbits decay, they fall toward Earth. Some 100 to 150 tons of space junk fall into the atmosphere each year, according to Heiner Klinkrad, the head of ESA's Space Debris Office. Most debris burns up in the atmosphere or lands unnoticed, ESA Space Debris Office deputy head Holger Krag told the Associated Press. On average, "roughly every week you have a reentry like GOCE," he says.

One of the best-known reentries is NASA's Skylab space station, which fell from orbit in 1979. About 82 tons of material hit the Earth, some landing in Australia and the rest falling into the Indian Ocean. In 2001, fragments of Russia's 150-ton Mir space station came down in a controlled dive into the Pacific Ocean. More recently, in 2011, NASA's UARS satellite crashed into the Pacific and Germany's ROSAT satellite landed in the Bay of Bengal. 

When a satellite falls, space debris can be spread over hundreds of miles. Dr. Krag noted that fragments from a satellite came down in 2011 over the Netherlands, Germany, and the Czech Republic, but no pieces were ever found.

No known human injuries or significant property damage have been caused by falling space junk, according to NASA, but there have been some destructive collisions in space – though none as dramatic as presented in the movie "Gravity." In 1996, a French satellite was damaged by debris from a French rocket that had exploded a decade earlier. In 2009, a defunct Russian satellite smashed into a commercial satellite, single-handedly adding more than 2,000 pieces of trackable debris to Earth's orbit.

Material from the Associated Press was used in this article.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Splashdown! Falling GOCE satellite lands in the Atlantic
Read this article in
QR Code to Subscription page
Start your subscription today