Space Junk: The New Nemesis

Lately, space has become a very dangerous place. Not so much because of the natural hostility of that environment; not even by the weapons that orbit stealthily and silently waiting for the moment to act. The real Nemesis, experts say, are thetons of space junk,that in recent years have increased visibly. From scraps of old satellites, to empty rocket engines and stages, tools that the astronauts let loose, and even a glove.

On March 12, the three astronauts aboard theInternational Space Station(ISS) received an alarm signal to immediately take refuge inside a Soyuz spacecraft: a piece of scrap metal was flying in the direction of the orbiting laboratory. A hole in the hull of the ISS, however small, means decompression and loss of oxygen, with about 10 minutes of survival. The crew moved to the Soyuz, where they waited nervously for 10 minutes, attentive to the order to undock and return to Earth. Meanwhile, Mission Control watched the chunk with growing nervousness. “The chunk passed you by,” says Mark Matney, a space junk expert. “It’s the closest we’ve come to disaster that I know of.”

A month agocrashed two satellites in orbit(aIridium communications and aCosmos 2251Soviet Union), which were added to the dozens of satellites intentionally destroyed from time to time, to thicken the belt of garbage that adorns the planet. To be completely destroyed, a spacecraft must be hit with an energy of 40 joules of force for every gram of its mass. According to Nicholas Johnson, chief scientist for orbital debris at the Johnson Space Center in Houston, the satellitesIridium YCosmos They collided at 42,120 kilometers per hour, imparting 50,000 joules per gram of mass. The resulting debris field is unprecedented and is being analyzed by space agencies around the world. Some experts estimate that the collision produced about 10,000 tennis-ball-sized particles.

“The problem is that, unlike Earth junk, space junk moves at mind-blowing speeds of 5.5 miles per second,” says Jonathan McDowell, a Harvard astrophysicist who is dedicated to tracking all objects in orbit. ? Any object larger than the size of an aspirin flying at these speeds is capable of opening a hole the size of a television set.?

TheUS Space Commandkeep track of13,943 orbiting objects larger than 8 centimeters. Of these, only 900 are active satellites. The rest is rubbish. And that doesn’t take into account all the screws rampaging around the Earth every 90 minutes. Normally, NASA commands the ISS to move when one of those fireballs approaches. But in the case of last week the object had not been detected: its orbit was erratic and it entered and left the Earth’s atmosphere. Although the orbits of large chunks eventually degrade and objects burn out upon entering Earth, most of them remain in space for centuries.

“One piece that hits the ISS in the wrong place is enough to ruin everything,” says McDowell. There are some projects to design techniques for collecting space debris, but so far they are all on the drawing board. And lately some companies that make satellites and rockets are trying to design them to limit the amount of chunks generated during launch. But there is no regulation that enforces such measures.

As for the projectiles created by the collision of theCosmos and the Iridium,Johnson says he is concerned, since the 65 satellitesIridium The remaining ones move in circular orbits that intersect each other at the Earth’s poles. The debris cloud created by that collision will have created a high-density junk ring, through which all those Iridium satellites must now pass. “The risk is now going to be much higher.”

Angela Posada-Swafford