The Space Safety Coalition (SSC) has published new guidelines to protect satellites orbiting the Earth from being damaged by space debris.
The updated guidelines have been endorsed by more than two dozen organisations, and include the ‘rules of the road’ for avoiding collisions between space objects.
The report describes five classes of objects — non-manoeuvrable, minimally manoeuvrable, manoeuvrable, objects with automated collision avoidance and crewed spacecraft — and outlines rules they should follow to avoid a collision between two of them.
Generally, smaller, more manoeuvrable objects are the ones to move to avoid large, heavier objects. However, special coordination may be needed in cases of encounters between two spacecraft in the same category, or even if it is difficult to tell when a spacecraft has manoeuvred.
The SSC is an international organisation of satellite operators, aerospace companies and industry representatives. The organisation originally published a set of space best-practices in 2019, but it has now decided to update them given “the urgent need to protect space-based capabilities”.
“Initiatives like the Space Safety Coalition are an important step towards establishing international best practices and guidelines to protect the space environment, but it is not enough,” said Rajeev Suri, chief executive of Inmarsat. “The clock is ticking, and real action is needed.
“National regulators everywhere should now use their powers of granting market access to require that satellite operators adhere to best practices like those outlined by the Space Safety Coalition and beyond.”
The new guidelines reference updated standards regarding space sustainability and debris mitigation, including guidelines for how to dispose of spacecraft at the end of their missions, such as the timing for “passivation” of spacecraft to prevent debris-generating explosions.
In addition, the SCC also calls specifically on satellite operators to share information and avoid intentional fragmentation.
“These best practices clearly set aspirational targets to encourage all space actors to advance towards a safer, more responsible and sustainable use of space,” said Charles Law, senior manager of flight dynamics at SES Satellites.
Ray Fielding, head of sustainability and active debris removal at the UK Space Agency, said: “The growing issue of space debris and the avoidance of hazardous conjunctions is one of the biggest challenges facing the global space sector, and one of the key priorities of our National Space Strategy.
“The UK Space Agency has committed £102 million over the next three years to build capabilities for tracking objects in space and developing technologies, regulations and operating standards to reduce the risk posed by current and future debris and make space more sustainable for all.
“We are also backing the UK’s first national space debris removal mission launch in 2026 and have recently launched the ‘monitor your satellite’ service which gives collision warning information to UK satellite operators.”
The European Space Agency (ESA) estimates there are 36,500 objects larger than 10cm currently floating in space, alongside 130 million pieces of space debris between 1mm and 1cm.
Moreover, the number of satellites in low-Earth orbit (LEO) is expected to increase dramatically over the next few years. With contributions from companies such as SpaceX, Amazon and OneWeb, as many as 18,000 new satellites could be floating above the planet by 2025. To date, Elon Musk’s SpaceX alone has launched about 3,000 satellites for its space-based internet service, Starlink
Recently, a Nature study showed that there is a 1 in 10 chance of one or more casualties from space debris occurring over the next 10 years.
In May 2021, the International Space Station (ISS) was hit by a piece of space junk which took a significant chunk out of its 17m-long robotic arm. In November, the ISS was forced to alter its orbit in order to avoid a segment of a now-defunct Chinese satellite that was headed on a collision course.
Last September, the Federal Communications Commission (FCC) voted to reduce the deadline for the removal of unused satellites in low-Earth orbit from 25 years to five, in an attempt to “declutter” the region.
To date, 27 companies and organisations have endorsed the document, including major GEO satellite operators Inmarsat, Intelsat and SES as well as LEO satellite operators Iridium and Planet.