Page 6 - Trashing the Planet: Examining Our Global Garbage Glut

AVALANCHE IN SPACE

In 1978 NASA scientist Donald Kessler described a theoretical situation in which two objects
collide in space and break apart. The resulting debris collides with other objects, shattering
them into fragments, resulting in even more debris. More collisions follow, with the creation
of more and more debris—all of which threatens operational spacecraft. The scenario,
known as the Kessler syndrome, could wipe out satellites needed for critical jobs on Earth.
In 2016 Ben Greene, chief executive of the Australian Space Environment Research
Centre, determined that the Kessler syndrome is a very real concern: “The most
pessimistic mathematical model says that we are within five years of having a 50-50
chance that a catastrophic avalanche of collisions will occur any day. The most optimistic
model says we’ve got 25 years.”
Some scientists say that the Kessler syndrome is already happening, but in slow
motion. Each small collision results in an uptick in the amount of space junk and the number
of other small collisions. While not as dramatic as Greene’s “catastrophic avalanche,” the
end result will ultimately be the same.

components on space vehicles. And each crash creates hundreds of new
pieces of threatening debris. For example, the accidental 2009 collision of
US communications satellite Iridium 33 and the Russian zombie satellite
Kosmos 2251 created thousands of pieces of space debris larger than 4
inches in diameter.
Most orbital debris is the unintentional by-product of space
exploration. However, in 2007 China sent shock waves through the
space industry when its military deliberately destroyed a Chinese weather
satellite with an antisatellite (ASAT) weapon launched by a ballistic
missile. ASATs are designed to destroy enemy defense and spy satellites,
and China wanted to test its ASAT capabilities. The ASAT blew the
weather satellite to pieces, creating around 950 pieces of space junk.
Nicholas Johnson, NASA’s chief scientist for orbital debris, commented on
the test: “Any of these debris has the potential for seriously disrupting or
terminating the mission of operational spacecraft in low Earth orbit. This

84 TRASHING THE PLANET