With various countries across the globe striving towards wireless internet connections, their move could cause the earth’s orbit to fill with dangerous space junk.
Experts believe that we may create a new problem one up in space while trying to solve an Earth-bound problem. Researchers from the University of Southampton have revealed that “mega constellations” of satellites – usually the course taken to set up country-wide wireless internet – could pose a serious threat to the Earth. They have identified various projects, such as the Indian Regional Navigation Satellite System mapping system (that increase the number of satellites in the space), saying that the increase could result in much more space junk floating around our planet, creating a hazardous environment in its orbit.
Researchers also predicted that there would be around 50% increase in satellite collisions due to the rise in orbital traffic in recent years. Commenting on the issue a couple of days ago, lead researcher and Senior Lecturer (Aerospace Engineering) at the University of Southampton Dr Hugh Lewis said that more space junk in the Earth’s orbit would certainly increase the likelihood of future accidents. “The constellations that are due to be deployed from next year contain an unprecedented number of satellites, and a constellation launched without much thought will see a significant impact on the space environment because of the increased rate of collisions that might occur,” he added.
Dr Lewis further said that they found about 750,000 objects orbiting the Earth at an average speed of 40,000km per hour. Claiming that its impact could deliver the energy equivalent of an exploding hand grenade, he stressed that it would not only damage the satellite impacted and affect its services, but also cause pieces to drift into their own un-monitored orbit.
Meanwhile, the lead researcher urged the European Space Agency (ESA), which funded the research, to place satellites to lower altitude orbits in future and to allow them to burn up in the atmosphere. According to Dr Lewis, it is important for future satellites to discharge its batteries and empty its fuel and pressure tanks in order to avoid possible explosions.
Head of the ESA’s Space Debris Office Dr Holger Krag has admitted that companies, who plan to launch satellites, lack enough experience in dealing with the consequences of overcrowding in Earth’s orbit. He said that it would be expensive to manufacture satellites with an ability to discharge its batteries. “They are companies so they have competitors, so they have pressure,” Krag said. “Under these conditions, they would have to manufacture satellites that are reliable enough after five years of operations to reliably conduct this disposal manoeuvre. Right now, all the taxpayer-funded space flight we are doing today is only able to achieve 60% of success rate for that manoeuvre. How can they be better under commercial pressure and with cheaper satellites? That’s the worry we have,” he explained.
Another difficult task is to clean the cosmos. That is why scientists have sounded an alarm over the problems posed to space missions from orbital junk – the accumulating debris from mankind’s six-decade exploration of the cosmos.
Scientists have mentioned that there are around 17,000 man-made objects in space monitored from the ground. Just 7% of these are functioning satellites. As per their estimation, there are 5,000 objects with sizes more than 1m, while 20,000 items are bigger than 10cm and there are also 750,000 “flying bullets” of around 1cm. The number of objects, larger than 1mm, is around 150 million.
Scientists have claimed that each piece of such objects travels at up to 28,000km per hour and collisions between pieces of hardware add to the scattering of small pieces. Even, the remaining fuel in defunct rocket parts can cause explosions. The regions near the polar orbits at 600-1,200km are the most congested areas, while two-thirds of the objects orbit below 2,000km. Every year, there are around 250 explosions and collisions.
As the debris cannot be controlled, scientists are trying hard to alter the course of functioning hardware. The ESA, for example, carries out about three collision avoidance manoeuvres a year. There are also proposals aimed at slowing down the track of large pieces or altering their course to lower their orbit, eventually leading to a fall of the object towards the earth and burning up.