‘Mega constellation’ is the grandiose term for large fleets of Low Earth Orbit (LEO) satellites, often numbering in the thousands. Satellites orbiting at lower altitudes need to move extremely quickly to maintain their orbit. This means to achieve global coverage with LEO satellites a constellation of many satellites is required. In the case of mega constellations, this can mean fleets of thousands.
80% [of Starlink satellites] will remain visible
Some even argue that the large amounts of dead satellites re-entering Earth’s atmosphere from these mega constellations has the potential to alter the chemistry of the upper atmosphere, possibly even disrupting the ozone layer. In this sense, mega constellations constitute a large uncontrolled experiment in geoengineering.
Satellites in the night sky will reflect sunlight back to Earth, much like the moon, causing bright rapid streaks over the sky. While Starlink has tried to mitigate the reflectivity of their satellites, 80% will remain visible. Not only will this destroy the precious beauty of the night sky which has inspired humans for millennia, it is also an existential danger to ground-based astronomy. The satellites will both directly disrupt observations and more generally increase the total sky brightness, making observations more difficult.
In Durham we are blessed with a beautiful night sky. The North Pennines has some of the country’s darkest skies (and is celebrating with a stargazing festival from 22nd – 31st October). Not too far north is the Northumberland Dark Sky Park, the largest dark sky park in the UK. The inherent awe of a clear night sky connects humans now with all those that have come before; some of the world’s oldest cave paintings depict constellations. Yet, the night sky is under threat from mega constellations.
In the last two years the number of satellites in LEO has increased by more than 50%, to 5,000. SpaceX alone is due to add an additional 11,000 to complete its Starlink project and has plans to add another 30,000 satellites. The goal of many of these projects (including Starlink and the UK’s OneWeb mega constellation) is to provide global broadband internet coverage to sell via various different business models.
What can be done to limit the spread of these mega constellations? Space is considered res communis, a legal concept derived from Roman law that translates from Latin as ‘common things’. This means that space is considered to belong to everyone — the common heritage of humanity — rather than being claimable to any person or country. Though this doesn’t render space lawless. Instead, it is governed by international law.
Via international law countries are, for example, able to prosecute their citizens even if the crime was committed out of the country. Even if the crime was committed in space. This principle came to the fore in 2019 when NASA astronaut Anne McClain was accused of committing the first ever crime in space, allegedly accessing her wife’s bank account improperly while onboard the international space station (ISS). They were later cleared of any wrongdoing.
We urgently need international governments to agree to a new multilateral treaty that recognises how technological development has changed the outer space threat horizon But what laws protect the low Earth orbit? The main basis of international space law is the antiquated 1967 Outer Space Treaty. Conceived at the height of the Cold War, the Outer Space Treaty mainly focuses on limiting military activities in space. At the time of the treaty there had only been around 40 successful satellite launches, most of which had already returned to Earth. The treaty is definitely not suited to a world with thousands of satellites cramming for space in one part of Earth’s orbit.
To preserve the night sky, the low Earth orbit, and apply the precautionary principle to the possible effects of mega constellations on the atmosphere, we urgently need international governments to agree to a new multilateral treaty that recognises how technological development has changed the outer space threat horizon. The UN’s Committee on the Peaceful Uses of Outer Space (COPUOS) has been working since 1959 to encourage international collaboration in the peaceful use of space. Now, more than ever, international governments must be emboldened to come together via COPUOS, to put aside geopolitical rivalries, and to negotiate a new treaty to save the night sky.
Image: PIRO4D, Pixabay