2021
Contribution to conference  Restricted

Consequences of mega-constellations for the low LEO region

Pardini C., Anselmo L.

Space debris  Satellite  Mega-constellations  Low Earth orbit  Space operations  Sustainability  Safety 

Since the definition of a Low Earth Orbit (LEO) protected region, at the beginning of the 2000s, most of the attention of the space debris mitigation community was focused on heights greater than 600 km. In such orbital regimes, in fact, the average residual lifetimes of inert satellites and rocket bodies become typically higher than 20 years and the highest concentrations of functional satellites and space debris were found. The low LEO region, below 600 km, is however extremely important for space applications. In fact, since the last Apollo mission to the Moon, all human spaceflight was carried out there and also extremely important scientific missions, like the Hubble Space Telescope (HST), are orbiting in this volume of space. In recent years there was a dramatic increase in the launch rate of small satellites and cubesats in low LEO, boosting the number of potentially risky objects to be tracked and monitored. But the most dramatic development currently going on is the deployment of mega-constellations of satellites, with almost 10,000 spacecraft planned only in low LEO in the coming years. Even though any failed satellite of the planned systems will decay from orbit in much less than 25 years, therefore formally complying with current international space debris mitigation guidelines, it is realistic to expect a relatively high number of failures, considering the experimental nature of spacecraft tested in space, and in great numbers, for the first time. The short- and medium-term consequences for the satellite operations in low LEO might therefore be far from negligible, not to mention the negative effects on astronomy and the observation of the night sky. In the coming decade, a significant increase of close approaches and collision avoidance maneuvers in low LEO should be expected mainly due to: 1) The great number of non-maneuverable nanosats launched below 650 km; 2) The failed satellites of the mega-constellations launched there; 3) The disposed satellites of the mega-constellations launched in high LEO, either failed or with reduced maneuverability and/or operability; 4) A greater number of disposed satellites not belonging to mega-constellations, in order to comply with space debris mitigation guidelines or standard. The aim of this presentation is mainly to review the new challenges to be faced by spacecraft and space operations in low LEO due to these quite recent developments and to the current launch forecasts.

Source: 43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021



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BibTeX entry
@inproceedings{oai:it.cnr:prodotti:443478,
	title = {Consequences of mega-constellations for the low LEO region},
	author = {Pardini C. and Anselmo L.},
	booktitle = {43rd COSPAR Scientific Assembly 2021 (Hybrid), Sydney, Australia, 28/01/2021 - 04/02/2021},
	year = {2021}
}