What happens to the space debris?

What happens to the space debris?

Space activities have an impact on the environment and one of the consequences is space debris. Facts, numbers, comments and scenarios

Earth's orbit is becoming increasingly crowded… with space debris.

Human activities leave too many dead satellites and scraps of machinery discarded in Earth's orbit. Space junk clutters orbits and poses an urgent threat to weather, security, communications and other satellites.

Without forgetting the debris of the Chinese 'Long March 5B' rocket that carried the central module Tianhe (Heavenly Harmony) returned uncontrolled into the Earth's atmosphere last May.

If left in orbit, space junk could pose significant problems for future generations, making access to space increasingly difficult or, at worst, impossible, the New York Times reports.

“There are 4,300 satellites operating around the Earth while space debris from one millimeter to 10 centimeters large can be around 130 million. Collision with even a single centimeter-sized fragment can cause serious damage. Who will be responsible for the disposal of the "space debris"? " underlined the president of Leonardo Luciano Carta speaking at the conference "G20-Italy for space, economy, industry, rules" of the Leonardo Civiltà delle Macchine Foundation .

The theme also poses a challenge for regulators and satellite operators, notably SpaceX and Amazon, and other companies seeking to build megaconstellations of thousands of satellites to broadcast Internet service to Earth from low Earth orbit.

All the details.


For space junk, the implications are strong. More than 2,500 objects larger than four inches are currently orbiting at an altitude of 250 miles or less. In the worst case, an increase in orbital life of up to 40 years would mean fewer objects are being dragged into the lower atmosphere. Objects at this altitude would proliferate 50 times to about 125,000.


A report from the Office of Inspector General (OIG) released earlier this year highlights that NASA has done a good job deorbitating its spacecraft and rocket bodies. However, many other nations have not been as proactive, launching spacecraft and rockets that stay in orbit longer than the recommended 25 years.

As such, experts warn that the US space agency will need to both mitigate junk already in space and prevent the creation of future junk to keep spacecraft safe in the future.

The OIG also recommended NASA to develop a better means of tracking and understanding the nature of space junk in orbit.


In August, Hugh Lewis, head of the Astronautics Research Group at the University of Southampton, UK, noted that over half of the "close encounters" or "high risk of collision between satellites" are due to Starlink, the constellation. SpaceX satellite.

Starlink aims to create "the most advanced broadband Internet system in the world". It has already launched about 1,700 satellites into Earth's orbit, which are responsible for about half of all near misses currently, Professor Lewis's research suggests.

Lewis examined data from the Socrates database (Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space), which tracks the orbits of satellites and models their trajectory to assess collision risk. He looked at the data in May 2019, when Starlink launched its first batch of satellites. Lewis said the Starlink satellites are responsible for 1,600 close encounters between two spacecraft per week. Excluding near misses involving two Starlink satellites, the figure was 500.

The Starlink satellites will ultimately be responsible for 90% of near-misses in Earth's orbit, the scientist predicts.


Meanwhile, the European Space Agency's space junk report released last year found that the disposal of deceased spacecraft in orbit is improving, but happening at a slower pace than necessary.


But the European Space Agency did not stand by and watch.

Just at the beginning of September, ESA awarded a contract to the Como-based company D-Orbit through its British subsidiary to develop the technology for the removal of space debris.

The order, worth 2.2 million euros, is part of the ESA space security program.

The contract involves the development and demonstration in orbit of a “Deorbit Kit”, an autonomous package of devices that will allow spacecraft of any size to perform propulsive disposal maneuvers.

The company will lead a consortium including Airbus Defense and Space, ArianeGroup, GMV Innovating Solutions and Optimal Structural Solutions to develop the multipurpose kit. This will initially be installed on a Vega rocket payload adapter called Vespa (Vega Secondary Payload Adapter). The kit will be installed prior to launch to perform a propulsive re-entry maneuver on a designated uninhabited area shortly after the payload is released.


As Axios revealed, experts are working to come up with new models to understand exactly how different types of spacecraft and materials move in orbit. The aim is to make tracking more effective.

Moriba Jah of the University of Texas explained to Axios that he is trying to quantify the "carrying capacity" of certain orbits to know exactly how many satellites can and should be launched in various parts of space. In this way, they would allow to establish whether certain constellations can be launched.
Jah and other experts are also calling for better international collaboration on the space junk problem, with the US lagging behind others (such as Europe) in addressing the problem in innovative ways.


And even in Italy, institutions and companies in the space sector are questioning the issue of space garbage.

“We have three challenges to face in the near future: establishing guidelines for satellite traffic, to contribute to a sustainable use of space; the impact that space activities have on the environment with particular attention paid to space debris; regulate the space exploration and colonization sector ”declared the Minister for Technological Innovation with responsibility for Space, Vittorio Colao speaking at the first day of the G20 Space Economy Leaders Meeting 2021.

“In such a dynamic context, which provides for new opportunities, certain rules are needed: until a few years ago, the management of orbital spaces mainly concerned communications only. Now we need rules for access and interactions in space ”recently reiterated the number one of the Italian aerospace and defense giant Leonardo Alessandro Profumo.

“Where there are more and more satellites, space debris increases, with all the associated risks, rules must be established and responsibilities defined” underlined Alessandro Profumo.

This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/innovazione/che-fine-fanno-i-detriti-spaziali/ on Sat, 25 Sep 2021 04:11:58 +0000.