Antinuclear

Australian news, and some related international items

Space junk cowboys are ruining our night sky

 https://www.theage.com.au/national/space-junk-cowboys-are-ruining-our-night-sky-20221212-p5c5kw.html

Virginia Kilborn, Swinburne University chief scientist January 15, 2023

Without action, over the next decade the night sky as we know it will change drastically. Where once we saw constellations of stars, we will see moving constellations of satellites – hundreds and maybe thousands of them moving across the sky. The magic of a shooting star will be lost.

The constellations your parents once pointed out will be harder to find, and as Kamilaroi astrophysicist Krystal De Napoli has explained, the vital reference points that our First Nations astronomers have relied on for tens of thousands of years will no longer be visible.

Astronomers are already dismayed that their view of the universe is increasingly masked owing to optical and radio emissions from the thousands of objects overhead that make it more difficult to conduct paradigm-shifting research.

When it comes to access to space, we are undergoing a technological revolution. Once the domain of multinational companies and government agencies, the new space race is dominated by agile and comparatively young companies taking advantage of small satellite technologies, such as CubeSats –  nanosatellites the size and shape of a Rubik’s Cube.

These smaller satellites allow companies to quickly test new technologies in space and take less energy to launch to their lower-altitude orbits. While they offer significant benefits to us on Earth, such as monitoring weather patterns and natural disasters, and providing internet access to remote communities, they are less reliable, have higher failure rates and shorter lifespans than previous satellites.

We’re seeing the advantages of new design and advanced manufacturing technologies reducing the cost of sending satellites into orbit. But we should also be concerned about disposable space hardware going down the same path as other technologies, such as low-cost plastics. Plastics have allowed for the development of low-cost products, but the lack of life-cycle planning means plastic waste pollution is prevalent across the planet. We need to avoid this short-term thinking when it comes to satellites.

Rather than launching satellites designed for decades of use – for example the GPS navigation system, comprised of around 30 satellites – many companies are now planning for the launch of mega-constellations of thousands of small satellites in low Earth orbit. In the US alone, the Federal Communications Commission is approving tens of thousands of satellites for launch.

Astra has applied for 13,000 satellites, SpaceX has more than 3000 satellites already launched and has sought approval for 9000 more (but they’re looking at more than 30,000 in the future). Amazon has plans for over 3000 more satellites, and Telesat plans for about 2000 satellites with just a 10-year life span.

While small low Earth orbit satellites are designed to burn up in the Earth’s atmosphere on the timescale of a decade or so, they deposit a higher concentration of aluminium than meteoroids. Over time, this will change the composition of the atmosphere. While the weight of satellite debris now entering the atmosphere is about 20 times less than that of meteoroids, satellites are mainly composed of aluminium; meteoroids are less than 1 per cent of that element. The long-term effects of this change could include changing the albedo, or reflective nature of the atmosphere.

With so many satellites in finite orbits above us, there is also a growing danger of collisions, which in turn could increase the amount of space debris orbiting Earth. NASA is already tracking more than 27,000 pieces of space junk and estimated there could be half a million pieces larger than 1 centimetre; and over 100 million pieces smaller than a centimetre.

Steps are being taken to tackle some of these issues. Here in Australia, space scientists, lawyers and policy experts from Swinburne University of Technology, EY, CSIRO’s Data61 and SmartCat CRC are working on a regulatory framework for AI-enabled systems that can operate to avoid collisions, while other projects are looking to remove existing debris and defunct technology from orbit.

Further afield, the International Astronomical Union has formed the Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference to work with technology companies and policymakers to ensure we preserve the night sky for research.

There is a new voluntary sustainability rating being promoted by the World Economic Forum and the US Federal Communications Commission has recently changed the regulations regarding low Earth Orbit satellite disposal, requiring a much quicker re-entry into the atmosphere to ensure these items don’t clog up our sky.

These are positive steps, but we need to go further and reconsider whether we need to launch thousands of satellites in the first place.

Finding better ways to do things now means both harnessing space to improve life on Earth and avoiding the destruction of one of our greatest assets – the night sky

Advertisement

January 16, 2023 - Posted by | Uncategorized

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: