It’s getting crowded up there.
Last month, two orbiting satellites smashed into one another nearly 500 miles above Siberia, shattering both the satellites and spraying more than 600 chunks of debris that now pose a danger to other satellites, including the International Space Station and the Hubble Space Telescope.
The two ill-starred birds were the American Iridium 33, a communications satellite, and the Russian Kosmos 2251. Iridium 33 was in a polar orbit, the Kosmos satellite in an equatorial orbit, nearly perpendicular to Iridium 33. Their crash is an indication of how crowded orbital space is becoming.
Several weeks after their collision, a piece of space junk whizzed close enough to the space station that ground control ordered its three-man crew to get into one of their Soyuz spacecraft “lifeboats.” Even though it was no more than a few inches across, if that piece of debris had hit the space station it could have shattered one of its electricity-generating solar panels, or even punctured one of the station’s living modules or labs.
Fortunately it missed. But there’s more and more junk up there to worry about.
NASA and other space organizations have fretted about space junk for more than 20 years. Last month’s satellite smash-up has brought renewed attention to their fears.
There are thousands of objects drifting through orbital space that are large enough to be tracked by ground-based radars. Some of them are chips of paint that have flaked off spent rocket boosters. Over the years and decades of space operations, chunks of broken-up boosters, bits and pieces of equipment, even tools fumbled out of the hands of spacewalking astronauts have added to the growing field of garbage orbiting up there.
The old adage that “what goes up must come down” doesn’t apply in space the way it does here on the ground. Any object that’s moving at 5 miles per second roughly parallel to the Earth’s surface is going to stay up there in orbit — unless and until something happens to bring it down.
And an object moving at 5 miles per second can be as deadly as a sniper’s bullet, even if it’s only the size of a fingernail clipping. Space shuttles have been dinged more than once by space garbage. The International Space Station, orbiting about 200 miles up, makes a much fatter target; it’s about the size of a football field.
Engineers have proposed several ideas for getting rid of orbiting junk. Most of them revolve around a simple principle: If you can somehow slow down the bits of debris, they will fall into lower orbits and eventually spiral down into the Earth’s atmosphere, where they will burn up like tiny, man-made meteors.
One possibility that was bandied about a couple of decades ago was to place a sort of Nerf ball in orbit, moving in the opposite direction to the space debris. When a piece of junk hits the semiflexible Nerf ball, it is slowed down and begins its one-way spiral into the atmosphere.
A more recent idea is to launch a tank of water — plain old H2O — into orbit and spray it along the altitude where most of the junk is flying. The water cloud will slow the debris, theoretically.
I had fun with the problem of space junk in a short story I wrote nearly 20 years ago. I titled the story “Vacuum Cleaner,” because it dealt with attempts to clean up the vacuum of orbital space.
The story’s hero was Sam Gunn, a character I’ve written many stories about. Sam is a short, smart, loud-mouthed womanizing businessman who is constantly making fortunes in various space businesses — and then losing them again on some new venture. He has a big heart, grand visions and a host of friends. He also has an army of enemies, because Sam is always battling the “big guys,” magnates of major corporations and bureaucrats of national governments and international organizations.
Sam goes into the “vacuum cleaning” business to make money. And the time may be right, today, for someone to do just that.
Orbital space is getting more crowded with every launch. Space debris is generated every time a booster lifts off the ground. If — or rather, when — enterprising businessmen such as Richard Branson of Virgin Airlines and Virgin Galactic begin offering space flights to tourists, the garbage problem is going to get even worse.
Space enthusiasts dream of orbital hotels and even retirement centers in the weightlessness of orbit. But unless somebody begins to clean up the growing clouds of space junk, building such facilities in space will be almost like pitching a tent in the middle of a shooting gallery.
None of the proposed “vacuum cleaning” systems has been tried, as yet. As so often is the case, the question of cost comes up. How much will it cost to launch such systems? How serious is the threat of space junk? It seems to me that the seriousness of the threat increases every year, while the cost of launching cleanup systems should be going down.
At some point those two curves will intersect, and we will see serious efforts to remove space debris from orbit.
Incidentally, in my short piece of fiction I have Sam Gunn and his associates affix a magnetic bumper to the orbiting space station. Objects in space tend to pick up an electrical charge as they orbit through the clouds of electrified particles that rain down on Earth from deep space. An object with a significant electrical charge can be deflected by a powerful magnetic field.
In “Vacuum Cleaner” I used a superconducting magnet to surround the space station with an invisible bumper that deflects space debris away from the station. It worked fine. That’s the advantage of fiction: you don’t have to make the contraption work right in the real world.