The more than 5,000 space launches over the past 50 years have generated more than 600,000 space-junk objects larger than 1 cm that are currently in Earth orbit. There are even more objects which are smaller and offer nearly equal dangers to astronauts, satellites, and manned space stations. Of the total number, about 12,000 are baseball size and larger. In 2007 alone, the amount of orbiting space debris increased by 25%. Over the years, space shuttle flights have been adjusted and satellite orbits changed to avoid this debris. However, satellites and space shuttle flights have still impacted this debris, generally without major damage so far. But when hitting any object at 25,000 miles/hr, the potential for catastrophic events are surely there. A collision with space debris also has the possibility of producing even more space debris (Kessler Syndrome).
Fortunately, much of this debris is in low Earth orbits, where atmospheric drag slows down the objects and causes them to fall out of orbit in relatively short order. This orbiting debris goes back to Vanguard I, the U.S.’s first satellite, which was launched in 1958, fifteen years of garbage bags from Soviet cosmonauts, remnants from defunct of destroyed satellites, and various other items.
This is not a new or ignored problem, considerable research and experimentation has been done to evaluate the degree and extent of damage from space junk. However, there’s no effective way to clean up this mess and the amount continues to increase. Additionally, the number of countries with active space programs continues to increase and their individual activities are growing as well. China’s space program, for example, now has more than 200,000 engineers and technicians involved in R&D work for its manned space and lunar programs, along with its secret military programs. There are also a number of commercial space operations being developed with additional launches of their own.
There are no rules, regulations, or even advisories about the generation of space debris. Most countries attempt a “best practice” to minimize the generation of space debris. But not always—the shoot-down of a Chinese satellite last year, for example, generated more than 2,300 objects 4 cm or larger, the largest single debris event in space history.
With as many groups launching as many objects into space and with the generation of more space debris with almost every flight, the danger posed to the new and existing, very expensive satellites increases. At some point in the future, the amount of space debris may reach a saturation point that severely limits or even prohibits the safe launch of new devices.
