independent– The rapid development of mega-constellations – like the ones proposed by Elon Musk’s SpaceX and Blue Origin’s Project Kupier – risks “potentially dangerous on-orbit collisions on a regular basis”, according to a new report.
The research, conducted by the University of British Columbia, says that the constellation of satellites proposed by huge companies could deposit more aluminium into the Earth’s upper atmosphere, while untraced debris and meteoroids could be the cause of numerous collisions, as well as the negative effects on astronomy often raised by researchers.
“De facto orbit occupation by single actors, inadequate regulatory frameworks, and the possibility of free-riding exacerbate these risks”, Aaron Boley and Michael Byers, write in the report.
“International cooperation is urgently needed, along with a regulatory system that takes into account the effects of tens of thousands of satellites.”
SpaceX’s satellite internet service Starlink is the best known of these mega-constellations. The company controls over a quarter of all active satellites, totalling over 1,000 crafts out of a total 5,000 in low-earth orbit – an altitude of between 160km and 1000km above the Earth. The report says that it plans to add another 11,000 more, and has filed for permission for another 30,000 with the United States’ Federal Communications Commission.
Moreover, since these satellites are mass-produced with few backup systems, the report says, the “consumer electronic model allows for short upgrade cycles and rapid expansions of capabilities, but also considerable discarded equipment.
“SpaceX will actively de-orbit its satellites at the end of their 5-6-year operational lives. However, this process takes 6 months, so roughly 10 per cent will be de-orbiting at any time. If other companies do likewise, thousands of de-orbiting satellites will be slowly passing through the same congested space, posing collision risks”, the report states.
Amazon, OneWeb, Telesat, and the Chinese state-owned GW, which recently allowed its Long March 5B rocket to fall, our of control, around the world are planning similar endeavours; but despite this commercial interest the current governmental regulations are “ill-equipped to handle large satellite systems”, the report claims.
This is because, while the volume of space is large, satellites specific functions that require specific altitudes and inclinations. This increases congestion and requires active management, the report says, as well as requiring improved communications between satellite operators.
In September 2020, astronauts aboard the International Space Station were ordered to shelter as a large piece of space debris was heading towards the craft, and emergency thrusters had to be activated to avoid what Nasa called a “possible conjunction” with the object. It was the third time since January that the space station had been forced into an unscheduled manoeuvre.
A SpaceX satellite and a OneWeb craft also reportedly came within 60 metres of crashing in April 2021. Starlink’s engineers could apparently do nothing to avoid a collision, turning off their autonomous movement system to allow OneWeb to navigate around them. SpaceX has claimed that is not true; neither company provided comment when asked by The Independent at the time.
“Internationally adopted ‘right of way’ rules are needed to prevent games of ‘chicken’, as companies seek to preserve thruster fuel and avoid service interruptions”, the report advises.
The report also raises space debris as a more serious concern, as while the probably of collision between a satellite – responsive or non-responsive – is “negligible”, there is little to account for untracked debris.
“The probability that a single piece of untracked debris will hit any satellite in the Starlink 550 km shell is about 0.003 after one year”, the report states.
“Thus, if at any time there are 230 pieces of untracked debris decaying through the 550 km orbital shell, there is a 50 per cent chance that there will be one or more collisions between satellites in the shell and the debris.”
There are also numerous environmental impacts: although SpaceX is building reusable rockets, with their second stages dropping in remote areas of the ocean, this is not achievable by other companies yet.
“Uncontrolled re-entries do not always meet safety standards, a situation that may be exacerbated by mega-constellations. Moreover, the cumulative impact of thousands of rocket stages on the ocean environment could be significant should those stages contain hazardous materials, such as unspent hydrazine fuels”, the researchers say.
“There is little recognition that Earth’s orbit is a finite resource, the space and Earth environments are connected, and the actions of one actor can affect everyone. Until that changes, we risk multiple tragedies of the commons in space”.