Leonard David's INSIDE OUTER SPACE

Credit: The Aerospace Corporation/CORDS

The number of artificial objects in space is growing rapidly, driven primarily by an increasing quantity of satellites in low Earth orbit.

Given that fact, a research paper points out that satellite technology can have a range of environmental impacts on Earth, not only from the effects of rocket launches and satellite de-orbiting on the atmosphere, but also biological impacts of a changing nighttime sky.

Earth clutter. This artist’s view shows the broad scope of space debris circling the planet, hundreds of miles above sea level, at the same height where low-Earth orbit satellites operate. The spatial density of debris objects increases at high latitudes. Note that the size of the debris elements in this image is greatly exaggerated compared to the size of Earth.
Credit: European Space Agency.)

“Given the acceleration in space-based activities, and particularly ongoing and predicted growth in the number of satellites in low Earth orbit, the impacts of artificial space objects on Earth systems need to be considered carefully,” states the research paper – “Environmental impacts of increasing numbers of artificial space objects” – published in the journal, Frontiers in Ecology and the Environment.

The paper’s lead author is Kevin Gaston of the Environment and Sustainability Institute, University of Exeter, Penryn, United Kingdom.

SpaceX Starlink Satellites over Carson National Forest, New Mexico, photographed soon after launch.
Credit: Mike Lewinsky/Creative Commons Attribution 2.0

Sky brightness

Gaston and colleagues observe that artificial skyglow (artificial sky brightness) may be impacted by spacecraft and orbital clutter might influence nighttime skies. “Indeed, this has been estimated already to be as much as 10% above natural levels as a consequence of satellites and space debris,” the paper adds.

Due to the current inability to retrieve orbital objects, “the only possible mitigation for debris is to launch fewer, design satellites with longer operational lifetimes, and seek ways to extend the life of existing satellites, thereby reducing the quantity for eventual decommissioning and removal,” the paper advises.

Categories of satellites according to weight with examples of
satellites that fall into these categories, and equivalent examples from the
animal kingdom. Note that very small satellites in the femo and pico size range are not shown. Image credit: Gaston, et al./International Space Station NASA/Wikimedia Commons

Why not move large debris to higher graveyard orbits further away from Earth’s atmosphere, where they will remain for hundreds of years?

That is a current practice, the paper points out, “but this too – we argue – is unsustainable, as doing so will ultimately lead to further debris congestion and pollution of space.”

Wider societal, cultural, environmental impacts

In supporting information to their paper, Gaston and associates argue that the major problem with the present-day Assessment of Environmental Effects (AEE) approach taken in the UK is that it fails to take into account the full life cycle of space activities. These considerations relate specifically to the immediate impacts of launch (e.g. rocket or airplane noise, point of launch emissions, air quality).

“There is no mention or consideration of what happens to the material propelled into orbit, nor the wider societal, cultural, or environmental impacts of those activities beyond the geographical boundaries of the launchpad itself,” the supporting document concludes.

To read the paper — “Environmental impacts of increasing numbers of artificial space objects“ – go to:

https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/fee.2624