Oh, the double-edged sword of technological advancement!
Imagine a world where tiny, intelligent machines orbit our planet, providing us with unprecedented connectivity and capabilities. Now, imagine those same machines, abandoned and lifeless, cluttering up our cosmic backyard, creating a hazardous minefield for other spacecraft.
Well, as it happens… we’re pretty much there.
That’s today.
The advent of small satellites — CubeSats or NanoSats — marks a significant milestone in the evolution of the space industry. These miniaturized devices are transforming the landscape of space exploration, offering cost-effective and versatile solutions for a wide range of applications. However, their proliferation also presents a significant challenge — the escalating problem of space debris, or 'space junk.'
The Rise of Small Sats
Small satellites, typically weighing between 1 and 10 kg, are becoming increasingly common in orbit. The technologies for mass production and miniaturization have allowed us to make these compact, cost-effective devices attractive to a broad range of players, and for a wide variety of applications — from telecommunications to environmental monitoring. Small satellites are also contributing significantly to space weather research. The weight of these satellites — less than 180 kilograms compared to up to 10,000 kilograms for a large satellite — brings their launch costs down, making them an ideal choice for the spaceflight testing of new technologies.
The Space Junk Dilemma
The proliferation of small satellites, however, is contributing to an already growing concern. Space junk refers to any human-made object left in space that no longer serves a useful purpose. This includes defunct satellites, spent rocket stages, and even tiny fragments like paint flecks. The increasing deployment of small satellites is exacerbating this issue because a significant proportion of them fail, becoming part of the space debris problem.
Here are some space junk stats:
Space junk and spacecraft travel at extremely high speeds — approximately 15,700 miles per hour in low Earth orbit. Collisions with space junk — even a tiny piece of orbital debris — can have severe consequences. Even a small piece of debris can damage or destroy satellites and spacecraft. This can lead to loss of scientific data, interruption of services like weather forecasting and telecommunications, and in the case of crewed missions, potential risk to human life (as Sandra Bullock and George Clooney experienced in the movie "Gravity").
Collisions also create more debris, through fragmentation, exacerbating the problem.
The United States Space Surveillance Network (SSN) tracks over 27,000 pieces of space junk. However, many smaller pieces are untracked but still pose a threat. It is estimated that there are 36,500 objects larger than 10cm, 1 million objects between 1-10cm, and an extraordinary 130 million objects between 1mm-1cm in size.
The number of space debris is projected to increase significantly in the future.
The Future of Small Satellites and Space Debris
In the grand scheme of space exploration, small satellites are both a boon and a bane. They are propelling us into a new era of space exploration, they are also democratizing that space exploration, and they are helping to drive innovation. But they are a double-edged sword as a result of contributing to the growing problem of space debris. Managing it will therefore be a critical aspect of space exploration. This is self-evident. It involves:
the development of effective strategies for space debris mitigation, and
ensuring that players adhere to international best practices for the operation of small satellites. (This will become more challenging as more private players become involved.)
As we continue to push the boundaries of what is possible, it is imperative that we also find ways to mitigate the impact of our activities on the space environment. The future of space exploration depends on it, as well as on our ability to preserve the space environment for future generations.
Sustainability — as it turns out — is not just an Earth's surface phenomenon.
Not anymore.
SOURCES:
Space .com: https://www.space.com/16518-space-junk.html
Openstax: https://openstax.org/books/university-physics-volume-1/pages/13-4-satellite-orbits-and-energy