How NASA dodged a derelict Soviet spy satellite

By the following day, the forecast had not improved much. The two satellites were predicted to occupy the same place within 30 milliseconds of each other.

"It was clear we had to be ready to move Fermi out of the way, and that's when I alerted our Flight Dynamics Team that we were planning a maneuver," said Dr. McEnery . 

Fermi's maneuver was to involve reorienting itself, retracting its antenna, and firing its thrusters, which were designed to move the satellite into the atmosphere at the end of its mission, where it would burn up and not pose a threat to other spacecraft. These thrusters had never been tested. 

"You can't help but be nervous thinking about highly flammable fluids heading down pipes they'd never flowed down before," said McEnery in the press release.

At noon on April 3, Fermi performed the maneuver, firing its thrusters for one second. The following day, the two satellites passed each other by a comfortable distance of six miles.

"A huge weight was lifted," McEnery said.

Since the launch of Sputnik in 1957, the Earth has become enveloped in space debris stretching for thousands of miles in every direction. The US , which tracks every artificial object in orbit larger than 10 centimeters, has counted some 17,000 objects. Of these, only about 1,200 are active satellites. The number of particles smaller than a centimeter, such as paint flakes, leaked coolant, and dust from rocket boosters, likely exceeds tens of millions. NASA says that spacecraft shielding can protect a craft from particles as large as one centimeter.

The greatest danger of space debris is that they can create a vicious circle known as the Kessler Syndrome. When objects in Earth's orbit that strike debris, they tend to create more debris, thus increasing the risk of future impacts, which would in turn create more debris, and so on, ultimately making space travel, and even the use of satellites impracticable because of the high risk of collision.

Previous

1 | 2