Space Debris: The growing disaster risk

Since the beginning of the space age, starting with the launch of Sputnik in 1957, humans have launched thousands of rockets carrying more than ten thousand satellites into space. The last few years have seen a dramatic increase in these numbers, and over the last few decades, there has been a change in the type of mission flown, with private companies launching smaller satellites than those launched by non-commercial agencies.

What goes up nearly always comes back down! Space junk, also called Space debris, is an artificial material that is orbiting Earth but is no longer functional. This material can be as large as a discarded rocket stage or as small as a microscopic chip of paint. The causes of Space debris are dead satellites, used-up rocket stages, batteries & solar panels, fragments created by collisions, explosions, electrical problems, and even just the detachment of objects due to the harsh conditions in space. Some of the tiny space debris can travel up to 40,000 km/h in orbit, giving insight into their hazard!

Here, we explore the impact of Space debris as a rapidly growing disaster risk.

ROLE OF UNOOSA TO ANALYSE & MITIGATE RISK OF SPACE DEBRIS

To mitigate the disaster risk of Space debris, it is crucial to collect data, forecast & track the possible hazardous objects in space. The United Nations Office for Outer Space Affairs (UNOOSA) is actively working to raise awareness about the growing danger of Space junk. It has made laws, guidelines & regulations to ensure that all satellite launching nations/companies work to keep space clean & safe. UNOOSA has collaborated with ESA and created a series of infographics and podcasts that tell the story of space debris, explain the risks and illustrate the solutions available to ensure future space exploration remains sustainable. Here is one of these interesting infographics that give importance to Re-entering debris into Earth’s atmosphere safely:

RISK OF SPACE DEBRIS RE-ENTRY

When it comes to the objects we send to space, atmospheric reentries are actually a fundamental tool in minimizing space debris and ensuring a sustainable future in space. Objects in low-Earth orbit, affected by the ‘drag’ forces caused by Earth’s atmosphere, gradually lower in altitude and then make a rapid and fiery descent towards Earth. Small objects disintegrate as they reenter due to the immense friction and heat created, but parts of larger bodies can reach the ground, so they should be controlled to land over uninhabited regions. So, if such huge objects are unregistered hence not timely detected or uncontrolled, we will surely face a huge disaster risk on Earth. The occasional impact on Earth will have detrimental effects on the environment. For example, debris from Russian Proton rockets, launched from the Baikonur cosmodrome in Kazakhstan, litters the Altai region of eastern Siberia. This includes debris from old fuel tanks containing highly toxic fuel residue, unsymmetrical dimethylhydrazine (UDMH), a carcinogen that is harmful to plants and animals. 

CHINA’S TIANHE ROCKET STAGE RE-ENTRY

A very recent example of a major space debris event was the re-entry of China’s Tianhe rocket stage. It was a huge concern for space agencies worldwide that China did not share details of the rocket stage whereabouts, such as the possible location of its re-entry & crash on Earth. The size of this debris posed a possible disaster risk. On 8 May 2021, the rocket stage plummeted into the Indian Ocean near the Maldives safely. But this event showed the possibility of a disaster caused by Space debris.

RISK IN SPACE (FOR SATELLITES & THE ISS)

Space debris is the only major cause that can impart a human catastrophe on Earth and in Space since humans have a constant presence in orbit in the International Space station. More missions are planned from 2022 onwards, such as the Chinese Space station, the Artemis Lunar mission that involves a human habitat in orbit of the Moon, are notable examples. The ISS has been hit by small space debris many times. Although these have minor damages, the upcoming habitat missions signify the need to make space a safer place by addressing space debris to prevent a big disaster. 

To understand the hazardous nature of Space junk, here is an interesting infographic showing the increasing number of unregistered objects in space which makes it more challenging to identify potential dangerous Space junk:

PRESENT SOLUTIONS

The main control room for potential space collisions is the U.S. Air Force’s Space Surveillance Network to track space debris. It shares its data with other space agencies and satellite operators to avoid collisions in orbit with space debris and sends out timely alerts. With the development of similar tracking centers in other space agencies, it is expected that the overall accuracy of space debris data will improve. Some space companies have developed workable solutions to mitigate their disaster risk. These include Astroscale’s Elsa-d mission launched in March 2021. The End-of-Life Services by Astroscale-demonstration (ELSA-d) mission will test a magnetic docking technique to remove debris from the orbit. The “servicer” satellite will use GPS to locate space debris and then latch onto it using a magnetic docking plate to carry it down toward the Earth’s atmosphere, where it will burn up. 

Another method is to extend the mission life of the satellite by in-orbit servicing. A mission that has already been successful is the Northrop Grumman’s Mission Extension Vehicle-2 (MEV-2) docking to the Intelsat 10-02 (IS-10-02) commercial communications satellite to deliver life-extension services. This took place in April 2021 and paved the way for minimizing space debris in orbit.

The fact is that Space debris has already become a big disaster risk in Earth’s orbit. It is set to pose a huge disaster risk detrimental for life on Earth if it is not mitigated efficiently.

USEFUL REFERENCES:

• ESA – Current state of spacedebris
• Unoosa – ESA Infographics
• Weforum – Space Junk
• Earth.org/space-junk/
• Space.com/Astroscale-cleanup-mission
• Northrop Grumman

Also, Read A CONVERSATION ON CLIMATE CYCLES AND THEIR IMPACT ON OUR PLANET WITH PROF. DR. NAYYER A. ZAIGHAM