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Showing posts with label space debris. Show all posts
Showing posts with label space debris. Show all posts

Monday, April 12, 2021

Australian National University (ANU) - New laser to help clear the sky of space debris [Phys.org, April 2021]

Title:
New laser to help clear the sky of space debris 
 
Author:
James Giggacher, Australian National University
 
Published:
Phys.org, 12 April 2021
 
From the article:
Researchers at the Australian National University (ANU) have harnessed a technique that helps telescopes see objects in the night sky more clearly to fight against dangerous and costly space debris. The researchers' work on adaptive optics—which removes the haziness caused by turbulence in the atmosphere—has been applied to a new 'guide star' laser for better identifying, tracking and safely moving space debris.
 

Friday, February 19, 2021

Steering reflective space debris using polarised lasers [Scholarly Article - Advances in Space Research, available online 14 January 2021]

Title:
Steering reflective space debris using polarised lasers 
 
Authors: 
Jouni I. Peltoniemi a, Olli Wilkman a, Maria Gritsevicha, Markku Poutanen a, Arttu Raja-Halli a, Jyri Näränen a, Tim Flohrer b, Andrea Di Mira b  
 
a Finnish Geospatial Research Institute FGI, 02430 Masala, Finland 
b ESA European Space Agency, ESOC, 64293 Darmstadt, Germany
 
Published:
Advances in Space Research, available online 14 January 2021
[Open access article]

Abstract:
Since realising the idea that a man-made object can be intentionally placed into the Earth’s orbit, almost 10,000 satellites have been launched for multiple scientific, commercial and military purposes. These activities produce a huge amount of junk comprised not only of defunct artificial objects that no longer serve a useful purpose, but various collisions, explosions and leaks have produced millions of pieces of objects of size varying from micrometers to meters. Space debris pose a threat to sustainable space and to the near-earth environment at large. As a result, there is a need for the removal of such objects in a controlled and well-planned manner, or at least safeguarding the most precious satellites from collisions. Among the proposed techniques to avoid collisions, the orbital laser momentum transfer method has good potential for altering the orbits of high area-to-mass-ratio objects (, typically a few cm in size), that are too numerous for capturing techniques. The method is based on the idea of illuminating the target with a laser that induces radiation force. Here we show that the control of the debris can be further improved by using the polarisation of the laser beam. Certain amount of debris objects, maybe around 10–20%, pose asymmetric against the beam, and reflect light asymmetrically and significantly polarisation-dependent. This provides an opportunity for the closed-ended problem by introducing an additional degree of freedom for the direction of induced momentum. We present the theory for polarised light dynamics, and develop a new scattering model for reflective space debris. The model is supplemented with laboratory measurements. We show that asymmetry of the targeted object in itself may turn the momentum 1–30° for typical debris objects, and polarisation of the incident beam is capable of further affecting this direction by several degrees.