What is Space Debris?
Space debris, sometimes known less politely as space junk, is debris of human origin which is in orbit around the Earth. Thousands of objects have been launched into orbit since the 1950s, and most of these objects have been left in place, rather than being brought back down. The result has been a huge accumulation of material orbiting the Earth, and in fact the space junk problem has become so severe that many operational spacecraft and satellites are at serious risk of damage from collisions with pieces of space debris. Several things have contributed to the accumulation of space debris. The first is abandoned satellites and other objects launched into space. The second is intentional release of various components of spacecraft, such as the stages used in in rockets. Space debris is also caused by accidental releases, ranging from tools dropped by spacewalking astronauts to sections which have fallen off satellites and other equipment in space. Explosions of old and unstable craft su
Space debris signifies the presence of material present in space as the result of various space missions. Since the start of space exploration with Sputnik 1 in 1957, there have been many a space mission, which have led to an accumulation of pollutants and junk not only on the surface of earth, but in the outer space as well. Many space shuttles setups are left in the orbit after they reach their destination or accomplish successful results. Satellites, spacecrafts and mission operations are also discarded at the end of the mission. While this process may appear harmless, this can have serious consequences because risky items such as separation bolts, jettisoned spacecraft parts, solar cells, solid fuel fragments, lens caps, momentum flywheels, nuclear reactor cores, clamp bands, auxiliary motors, launch vehicle fairings, and adapter shrouds are released in the space. Space debris also includes the junk left by astronauts and space scientists during or after their missions, for example
Ever since the Soviet Union launched the first space vehicle in 1957,4 manned and unmanned space programs have generated garbage called space debris.5 Space debris, also known as orbital debris,6 consists of natural or human made particles that circle the Earth.7 These particles remain in orbit until natural forces cause their orbits to decay into the atmosphere.8 According to the United States Space Command catalogue, over a span of forty years spacecraft have deposited nearly 10,000 traceable objects of measurable size into earth’s orbit.9 Scientists estimate that objects between one centimeter and ten centimeters in size number as high as 110,000 pieces.10 The number of smaller fragments between one millimeter and one centimeter is believed to be at least 35 million.11 The number of microparticularate pieces left by spacecraft is estimated to be in the trillions.12 Human-made space debris, the focus of this paper, poses the primary risk to human activities.13 Natural debris usually
Johnson: Space debris, primarily, is anything in Earth-orbit that no longer has a useful function. That could include a non-functional spacecraft, a derelict launch vehicle upper stage, fragmentation debris, paint flecks, anything you can think of. NTB: Is space debris just manmade objects, or does it also include natural materials like meteoroids and things like that? Johnson: Normally when we talk about orbital debris, we’re talking about manmade objects. Meteoroids are in orbit about the sun and we normally refer to them as the natural environment. NTB: How does one become an expert in space debris? Is there a course of study you can recommend, or do you pretty much learn on the job? Johnson: Actually, orbital debris is a very small scientific community. Within the U.S., NASA is the principal source of orbital debris expertise and is the only organization which actually characterizes the orbital debris population from the smallest debris — microns — to the largest, which can be tens
It can best be classed as any manmade object that no longer has a practical use and includes empty upper-stages of launch vehicles, explosion fragments and dead satellites. Other items include cameras, gloves, wrenches and even a toothbrush lost by astronauts from past space missions. Any object weighing more than a few grammes and travelling at seven kilometres per second can easily destroy a satellite and pose a serious threat to future space missions. Just how serious is the problem? At present, the collision risk is very small; but space agencies and commercial enterprises are concerned that if further debris is created then certain orbits may in the future become too hazardous to use. Not only can space debris pose a threat to the global network of communication, navigation and Earth-observation satellites in Low Earth Orbit (LEO) but it could also hamper ongoing space projects such as the International Space Station (ISS) which is already protected by impact shield panels. What i
