Research and impact | By John Stevenson

Keeping pace with debris in space

The problems of pollution on land and at sea are well known. Now, one City PhD student is looking further afield, asking who should be held accountable for debris in space.


Since the dawn of the space age in the 1950s, there has also been the rapidly growing problem of space debris, which refers to any piece of machinery or debris left by humans in space – ranging from obsolete or failed satellites left in orbit at the end of their mission, to smaller objects such as pieces of satellites which might have fallen off rockets launched into space.


Since 1957, 6,370 rockets have been launched into orbit (excluding failures). Of these launches, 15,070 satellites have been placed into orbit with 9,790 still in space. 7,400 of these satellites are still functioning, creating some 10,700 tonnes of space objects in orbit.

However, The Natural History Museum estimates that there are around 34,000 pieces of space junk bigger than 10 centimetres in size, and millions of smaller pieces that could nonetheless prove disastrous if they come into contact with either humans or objects.


Several potentially catastrophic incidents (fortunately not involving the loss of any lives) illustrate the seriousness of space debris.


  • 23rd April 1958: the second and third stage of the Vanguard missile landed 1,500 miles from the original launch site.
  • 24th January 1978: the Soviet Cosmos 954 satellite made an uncontrolled landing over the Northwest Territories of Canada littering hazardous radioactive debris.
  • 9th July 2022: a module from a SpaceX Dragon spacecraft was found on a farm in New South Wales.


Although public international law holds spacefaring nations liable for damage caused by objects launched into low-Earth orbit, those states cannot be punished for littering junk in the natural environment of space.


Miguel-Ricardo Nkegbe, the recipient of The City Law School’s first ever PhD Scholarship for Black Researchers, is writing his dissertation on the extent to which the private sector can assist spacefaring states to adopt sustainable norms to address the space debris problem.

Miguel-Ricardo Nkegbe

Miguel-Ricardo says space debris should be seen as belonging to the ‘pacing problem’, first propounded by best-selling author Larry Downes. The pacing problem arises where “technology changes exponentially, but social, economic and legal systems change incrementally”.


Miguel-Ricardo believes that the secondary law-making power or regulatory policies of a government often play a far greater role in determining how to manage the risks associated with using innovative forms of technology in the public sector, than any primary law-making function.


There have been several Public International Law (or soft law) treaties which have sought to regulate the activities of space-faring nations. The opening text of the Registration Convention of 1974 (Space Surveillance & Tracking) calls for an ‘appropriate registry’ and ‘a mandatory system of registering objects launched into outer space, to assist in their identification’.


The Inter-Agency Space Debris Coordination Committee (IADC) created the world’s first ever space debris mitigation guidelines in 2002, and these guidelines have now been revised several times to continue influencing the international community: the European Space Agency eventually agreed to their own European Code of Conduct on Space Debris Mitigation in 2004.


Despite these guidelines being in place, however, Miguel-Ricardo says lawmakers do not have enough information at their disposal about the technological risks they need to regulate before enacting statutes around space debris reduction.


New private and commercial actors in the spacefaring space such as SpaceX, have provided additional challenges as well as opportunities for change.


He said: “There has been a change in the approaches which major spacefaring nations are taking towards accessing outer space sustainably, whereby they are working with a wider range of actors from the private sector on debris mitigation.”


Miguel-Ricardo thinks that “through the contractual adoption of voluntary soft law guidance on debris mitigation and removal, these private sector actors can have a significant influence on the approaches of space agencies towards sustainability in modern commercial space ventures.”


He says the private-public partnership (PPP) funding arrangements used in major infrastructure projects in the UK could offer a solution.


He cites the way that NASA and SpaceX have collaborated to engage in commercial space flights – via SpaceX’s Dragon spacecraft – to transport astronauts to the International Space Station and back more sustainably; and the PPP agreement signed to return NASA astronauts back to the moon on SpaceX’s Starship spacecraft.