Space Junk : Headache for Future


Space exploration has gained immense importance for the last 70 years. Though there is debate about the necessity of space exploration, today we can understand its importance in modern healthcare, information technology, communication systems, transportations, public safety, etc. Space exploration has helped us to deal with our environment and combat several problems created due to Earth’s increasing population. But the increase in the number of space exploration and a cold war among different countries to send frequent satellites has emerged a new problem in front of us. Just take a moment, close your eyes and think that ‘We could be trapped on Earth by our own trash sent to space’. Where the world is in deep problem to combat the e-waste such as used laptops, cell phones, electronic gadgets, the same is here in space.


Photo Courtesy:Wikimedia Commons

  Before a century it was believed that space is enormous. There is no scarcity of area in space. But with the development of space exploration, the scenario changes. Now the amount of non-functional space-crafts, nonoperational satellites, and human-made space objects are increasing day by day. These objects are consist of spent rocket stages, collision fragments, slag, dust from solid rocket motors, surface degradation products, etc. They are all termed as ‘space junk’, ‘space debris’ or ‘space trash’. Space debris or Junk (often called as space waste) are the objects in orbit around the Earth created by man i.e. artificial objects that no longer serve as useful purpose. Actually, they are massive  cloud, most are in the lower Earth orbit (LEO), orbiting around the Earth and consist of many nonoperational satellites, platforms, spacecraft and launchers sent by a human into space over past years. And as they collide between them or dis-integrate during high orbital motion, they create more and more debris. Space debris is threatening useful satellites and space stations or a spacewalking astronaut. The low earth orbit (LEO) has become increasingly populated with space debris and the probability of collision with others is increasing at a high rate. Though a maximum number of space junks are in the smaller ranges, their speed has made them much potential hazard. Most space debris is traveling hundreds to thousands of kilometers per hour. So, these tiny space debris can damage or destroy the satellites. The problem is so much important that in 2014, the International Space Station had to move three times to avoid deadly chunks of space junk. The condition if controlled not properly, it could lead to a serious problem for future space explorations. According to the European Space Operation Center (ESOC), more than 5000 launches have taken place since the beginning of the space age. From all those missions, about 23000 satellites are still in orbit but only 1200 are in operational mode. As per expectation, about 94% of objects in Earth orbits are space debris. In addition to that, the situation worsens as a major part of space debris can’t be tracked from the earth surface. According to various statistical models, about 166 million objects in orbit s are in the range of 1mm to 1 cm in diameter whereas about 30000 are exceeding 10 cm in diameter. The ESA and other space agencies have tracked about 42000 more large debris around the earth orbit. We can’t neglect the debris with small size as they can cause serious hazard with their relative high orbital velocities as they can reach 56000km/hr speed due to earth rotation. In this speed, a centimeter-sized debris can disable an operational satellite. Space debris with a diameter more than 10 cm can collide with satellites resulting in catastrophic breakups and that generate more and more space junks. This is termed as Kessler Syndrome.
The space debris is mainly nonoperational space crafts. Its number is increasing at a rapid pace due to auto generation or disintegration of its different parts. They are mainly due to an explosion in space-crafts at earth orbit, lost equipment, boosters, anti-satellite weapons etc. The majority of space junks are due to an explosion in rocket orbiting in high earth orbit (HEO). In general, during space missions, some extra fuel was carried out if needed unexpectedly. That unused fuel sometimes causes explosion and result s in the creation of space junk. The space junk or debris collides with other spacecraft or among themselves and more debris created. Debris was also created during spacewalk of an astronaut. They may lose equipment such as camera (As Sunita Williams of STS-116 lost her camera), garbage bag, gloves, tool kit, small gadget etc. Sometimes solid rocket boosters of the space shuttle do not reach orbital velocities and hence orbit near earth in an uncontrolled manner. So it becomes a serious debris problem. Anti-satellite weapons are generating a large number of space junks. Different countries are testing the capacity of its weapons by projecting in space. But these incidents are going to be uncontrolled and resulting in an increase in space debris.
   The space junk is becoming a threat to both manned and unmanned space-crafts. Some of the incidents were noticed about the destructive power of space debris. Due to collision with space debris COSMOS 1275 was destroyed in 1981. At 1996, CERISE (Fr) was damaged by ARIANE upper stage fragment and resulted in huge loss. Another massive incident happened when AM11 of Russia was disabled by space debris during a collision on 10 Feb 2009. Russian military communications satellite KOSMOS 2251 struck with Iridium 33, an American satellite and results in a huge disintegration of about 2000 sizeable pieces. Some of the near miss incidents also happened which can become devastation if a fraction of change take place. In 2009 and 2012 both COSMOS 1275 and Iridium 33 fragment nearly misses International space station target and some nightmare situation was avoided. In 2013, the largest space debris risk in earth orbit is derelict satellite named ENVISAT. Though contact was lost unexpectedly from April 2012 it is expected that it can stay in the orbit for the next 150 years until falls back into Earth’s atmosphere and burns up. So, finally we can realize how the situation is going to be worse and the risk of collision due to space debris is increasing in an exponential way. So the time has come to think in this matter and generate idea on how to combat space debris related hazards. There are only two paths – One is to restrict ourselves from all types of space explorations for the next thousand years and wait until space junks decrease naturally. The other way is to plan wisely how to reduce space junks using modern technology, knowledge of science and ideas. But the problem is that there is no international agreement, plan or management system to combat space debris problem. One might remove some important satellites of other countries during the cleaning of space junks. So, first of all, we need to set up space environmental management plan to preserve significant technology, reduce financial and intelligence loss due to damage of satellites, an international space junk removal strategy and strict rule so that all space mission must obey United Nations guidelines.
   After assigning different sides of the problem, some of the ideas are listed below to combat the effect of space debris. These may not be one stop solution or perfect but we can approach with them to get a clean space.
i)       Drag space junks to the desired location or bring back to Earth to burn up in the atmosphere. But this requires huge financial support. There are also suggestions of using LASER to nudge objects of course and throw them out of orbit.
ii)     Plan has been made to use robotic servicer space-craft which can chase down derelict satellites and harvest still usable hardware parts. Those useable parts can be used in the next mission.
iii)    Some have tried to launch a robotic janitor space-craft to grapples satellites from orbit and take back to Earth’s atmosphere to destroy them.
iv)   Other way is to reduce the future space debris by using re-usable rockets, Space X and some other commercial companies are experimenting with these types of projects. It will not only decrease the financial cost of space missions, but also definitely decreases the amount of space debris.

              But at last, we must keep in mind that human will power is the basic requirement to combat any problem. So we must aware of people about this space pollution. We should think that space is also our environment and polluting it can harm our natural day to day life. We live in a modern age where we enjoy live television broadcast, Internet, GPS, advanced mobile technology, etc. So if we do not take care to remove space debris, we may lose those great benefits. So we must clean our space for better tomorrow.

Note: This article was published in Akashganga Science Magazine, Nov 2017 issue


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