The space age began on October 4 1957 when the Soviet Union launched the first man-made Earth satellite. Sputnik I orbited between 100 and 600 miles above Earth’s surface. Although this was rather high by the standards of the day it is now called a low Earth orbit or LEO (pronounced like the name).
At LEO altitudes Earth’s atmosphere is very thin but there is still enough air to slow a satellite through friction and cause it to fall back to Earth. Sputnik I for example reentered the atmosphere three months after it was launched.
As space technology developed satellites were launched into considerably higher orbits thousands of miles high. Such orbits are called MEO (medium Earth orbit) to distinguish them from both LEO and those that are even higher than MEO. At MEO altitudes the atmosphere is so thin that it has almost no effect on the satellites. Spacecraft traveling in MEO violate the old adage “what goes up must come down” and are not expected to return to Earth within our lifetimes or even our grandchildren’s.
Some advanced satellites had parts that were needed only during launch. For example a telescope could require a protective lens cap that had to be jettisoned in orbit simply popped off by a spring and forgotten about. It went of course into its own slightly different orbit as a tiny MEO satellite but space at first seemed so big that nobody worried about it hitting anything else.
Well space is indeed big but not that big! As the MEO orbits have become more crowded they’ve begun to fill with “stuff.” Indeed collisions between spacecraft and debris have occurred causing hundreds of million of dollars of damage. These collisions in turn generate even more orbiting debris.
Space tracking systems routinely keep track of tens of thousands of pieces of space junk and these are only the objects larger than a few inches in size. Yet pieces of debris even smaller than that can also be dangerous due to their great velocities. One of the windows on the space shuttle Challenger for example was significantly damaged by a tiny particle that turned out to be a fleck of paint shed by some unknown satellite.
Due to the problem of space debris many MEO spacecraft are now equipped with small rocket engines to bring them back to Earth after they have outlived their usefulness. This is not practical for satellites in the higher orbits such as those 22 000 miles high in a realm called geosynchronous Earth orbit (GEO). At this altitude it takes 24 hours for a satellite to circle the earth. Since the earth rotates once in 24 hours the satellite appears to hover over a spot on the earth and antennae pointing at it do not have to move.
At GEO altitudes very large rocket engines would be needed to return the satellites to Earth which is not feasible. Instead when the spacecraft are no longer useful smaller rockets are used to boost them into still higher orbits. This domain more than 22 000 miles above Earth is called the “graveyard.”
The MEO domains continue to generate debris from collisions among objects already up there and no one knows what to do about this. Although no one is yet worried about filling up the “graveyard ” common sense tells us it is just a matter of time before that happens.
Modern man seems to believe in unlimited “progress.” Therefore someone will surely someday figure out what to do about space junk — right? A solution must be found because otherwise wonderful devices such as GPS navigators will cease to work in just another few decades.
Well must it be found? Once before in a place called Bavel people believed they were the masters of the universe and then learned differently. Will the abilities of man indeed lead to a solution of the space junk problem or will we again learn that the secular faith in man’s omnipotence is still false? —
Dr. Andrew Goldfinger holds a PhD in theoretical physics and a master’s degree in counseling and was a principal staff physicist at the Applied Physics Laboratory of the Johns Hopkins University. Dr. Goldfinger has lectured internationally on the interface between science and Judaism and is the author of a book entitled Thinking About Creation: Eternal Torah and Modern Physics.