Debris Pollution Could Wreck World Space Programs

By James Donahue

Last week’s “close call” experienced by astronauts occupying the International Space Station as a piece of space junk whizzed by has not surprised people involved in the space program.

Long before China used a missile to destroy one of that country's straying weather satellites in 2007 scientists were expressing serious concern about a growing amount of space debris circling our planet.

That is because every piece of junk floating in orbit around our planet is in motion and even the small pieces have the potential of blasting holes in the sides of the International Space Station, the shuttles that service it, or any future ships leaving or returning to Earth from missions to the Moon and beyond.

Collisions with larger objects would be a disaster in space.

For this reason, NASA and space officials around the world have been keeping careful track of every stray particle of every ship that has blasted off into space since the Russians sent Sputnik into orbit a half century ago.

An article by Leonard David published a few years ago addressed this issue long before the China incident. David noted that there is so much junk already circling our planet that he believed future missions are at great risk of collision.

He wrote: "Earth orbit is muddled with human-made hazards from numerous nations in the form of on-duty satellites, deserted spacecraft, leftover fragments of exploded rocket upper stages, even chunks of solid rocket motor propellant down to tiny flecks of paint shedding from space hardware.

"Toss in fast-moving separation bolts, lens caps, momentum flywheels, nuclear reactor cores, clamp bands, auxiliary motors, launch vehicle fairings and adapter shrouds. At one point, there was even a toothbrush reporting zipping through the global space commons," he wrote.

At that time, David reported more than 10,000 known objects larger than four inches in diameter that were being tracked by U.S. ground surveillance equipment. An estimated 700 of them were operating satellites. The rest was discarded flotsam. Today the number of objects has been increased to over 12,500 and growing.

"In addition to this there are millions of tiny bits of material, including droplets of radioactive coolant that eked out of poorly plumbed Soviet nuclear-powered spacecraft," David added.

Since the David article appeared, there have been a rash of new rocket and satellite launches by not only new nations entering the space race, but even private companies that are launching satellites for business reasons.

This is why both Russian and US space agencies expressed alarm when China used a guided missile to destroy that weather satellite. Not only did China display to the world its ability to knock spy satellites out of the sky, it blew this particular satellite into fragments that are now circling our planet like a hail of bullets that might strike anything that gets in their way. It was a piece of that particular Chinese satellite that came close to hitting the International Space Station.

At last count officials said they were counting 525 large pieces of metal and up to 600 smaller pieces of debris already passing within a few miles of orbiting satellites. And there are a lot of orbiting satellites up there. Not only do we have spy satellites, but our telephone system, or television programming, news feeds, and sophisticated guidance systems for ships at sea and commercial and military aircraft are dependent on information received from a growing number of orbiting technical equipment in space.

If you think space is so vast that all of this stuff shouldn't matter, think again. We have had close calls with shuttle missions, one of them returning with a cracked windshield from hitting something. Something damaged the Hubble Space Telescope in the midst of its operations.

The International Space Station has been moved several times to miss large tracked objects because of a possible hit from space debris. Operators of a German satellite were once forced to fire onboard thrusters to miss oncoming debris. It is a growing problem that has been intensified as more and more rockets are fired into orbit around our planet.

To put the seriousness of just what has happened since China blew up its satellite, the Johnson Space Center notes that it is now tracking a debris cloud that extends from 125 miles to 2, 292 miles, encompassing all of low Earth orbit. The majority of the debris is hanging in mean altitudes of 528 miles above the earth, or higher, which means that it will be up there for a very long time.

The number of smaller pieces of debris from this same breakup is even higher. NASA is estimating that up to 35,000 pieces of "riff-raff" larger than one centimeter in size is out there, flying like bullets in orbit and potential danger to any ship or satellite in space.

Another growing problem is the number of large pieces of space debris that are falling back to Earth. People occasionally reported a cluster of glowing objects coming down out of the sky. People usually think they are witnessing “falling stars” or meteor showers.  Instead they are pieces of space junk burning as they entered the atmosphere of the planet.

A 550-pound main propellant tank of the second stage of a Delta 2 rocket fell near Georgetown, Texas in 1997, Also a 156-pound piece of space debris fell near Riyadh, Saudi Arabia, in 2001. It is only a matter of time before someone gets killed by one of these monster objects crashing to Earth.

Oh man, what have we done to our planet and ourselves?