We need to debate space junk removal 4j4p5b

Who would have thought that the same man who dreamed of going to heaven and exploring the stars would start to worry about space junk removal to continue your adventures to infinity and beyond. Space has always been a mysterious and interesting place for human beings, who first looked up and created constellations and then went on to build rockets, satellites, ships and space stations. However, one of the main problems of their conquest of space became the generation and disposal of debris in earth orbit. 251m3v

These collisions will continue to happen - and increasingly, as the amount of space debris only increases - unless man starts not only discussing the removal of space debris, but begins to adopt effective measures that remove these objects from orbit. terrestrial.

What is space junk? 5q2b2c

The concept of detritus or space junk encomes all non-functional, human-designed objects that remain in space orbiting the Earth. This includes the parts of rockets and spacecraft that come loose during their ascent, satellites that have stopped working or have been abandoned, collision fragments among these objects, among other debris left by man in space.

According to European Space Agency (ESA), there are about 6250 satellites in space, only 3300 of which are still in operation, and the estimated number of separations, explosions, collisions or anomalous events, resulting in fragmentation, is over 550. thousand debris larger than 34 cm, 10 thousand objects between 900 to 1 cm, and 10 million objects between 128 mm and 1 cm.

Where is the space junk? 5250g

Earth has different orbits and three of them are low earth orbit ( LEO ), the mean Earth orbit (MEO) and the geostationary orbit (GEO). As the name implies, the LEO is the closest to us and also the most populous among the three – by the way, that’s where the International Space Station and that's where companies like SpaceX e OneWeb are sending several new satellites. Thus, it is not surprising that the LEO also be the region with the most space debris. 

However, regions of MEO e GEO they also deal with the problem of junk in space, as they host a number of crucial satellites, including navigation systems in the first, and essential communication systems based on the second. Given the altitude at which MEO (2 to 36 thousand km) and GEO (above 36 thousand km) are located, the solution found for when the satellites retire is to move them to unused orbits, called “cemetery orbits” – which continues to contribute to the rise of space debris above us.

What are the problems of space junk? 8636u

In 1978, Donald Kessler, scientist at NASA, understood that this could mean a catastrophe and postulated the theory “Kessler's syndrome", in which he said that more debris in orbit would increase the probability of collisions, increasing the amount of space junk to the point where Earth's orbit would be so polluted that it could compromise, partially or totally, future explorations.

The biggest contributor to the current space debris problem is in-orbit explosions, caused by leftover energy — fuel and batteries — aboard spacecraft and rockets. Although measures have been in place for years to prevent this, we see no reduction in the number of such events. End-of-mission discard trends are improving, but at a slow pace

Holger Krag, Head of ESA's Space Security Program

That is precisely what has been happening. THE International Space Station, whose in-orbit assembly began in 1998, was forced to perform maneuvers to avoid space debris 28 times since 1999 – 3 of them only in 2020. In 2009, there was a collision between an abandoned Russian military satellite (Kosmos-2251) with an active US communications satellite (Iridium 33) at speeds exceeding 41.800 km per hour. Both were immediately torn apart and resulted in 1.800 large pieces of space junk, which remain in orbit to this day and are capable of destroying any ship that crosses their path.

In addition to the risk of collisions between debris, space junk poses other challenges, such as light pollution that hinders observation of the night sky, even for observatories that often use equipment costing hundreds of millions of dollars.

Existing measures for the removal of space debris i5h5v

As space exploration continues at an accelerated pace (to provide Internet resources across the globe, the SpaceX wants to launch up to 42 satellites over the next few decades) effective measures will need to be taken to remove space junk — otherwise Earth's orbit will be so full of debris that it will be impossible to launch anything without a collision.

Currently, there are international guidelines and standards for space missions, in order to avoid the amount of garbage in space. Some of them are the creation of rockets and spaceships that minimize the amount of material released during launch and operation, release of stored energy, removal of disused objects out of the way of working satellites, among others.

In order to help clean up the space, Moriba Jah, a researcher at the University of Texas at Austin, built a viewer called AstriaGraph which displays the position of all actively tracked objects in the sky. He also designed a real-time graph that shows how closely these objects approach as they revolve around the planet.

Companies like Rocket lab have developed rockets that don't leave pieces of junk in space – they're made so the pieces de-orbit and burn up on re-entry into the Earth's atmosphere. In turn, startups as astroscale e d-orbit are making progress towards commercializing the removal of space debris.

A NASA has had for some time (since 1979), the Orbital Debris Program, whose objective is to look for ways to generate and release less debris in Earth orbit and to design equipment capable of tracking and removing space debris. The agency also implemented a rule that requires that once a satellite in low earth orbit is completed, the responsible party must have a plan for how to deorbit it in 25 years.

At the end of 2020, the ESA signed a contract worth 86 million euros with startup Switzerland ClearSpace SA to complete the world's first space junk removal mission. Once launched, the spacecraft Clearspace-1 it will be deployed to a 500-kilometer orbit for testing and then elevated to the target object's orbit for encounter and capture. Then the spacecraft will be placed in a destructive orbit to burn during re-entry to Earth.

Sources: Tech Crunch, National History Museum, ESA [1] [2], The Verge, NASA, Space news