Paul Kostek, Life Senior Member of IEEE and systems engineer at Air Direct Solutions LLC, discusses the actions needed to manage space debris caused by end-of-life satellites.
Managing the ever-growing volume of space debris poses a serious challenge. For international governments and industry leaders, questions have emerged with regard to how to dispose of it, what can be recycled, and what risk it poses to other satellite communications networks and space operations.
Currently, models show that there are over 40,500 remnants of space debris larger than 10cm and a staggering 130 million fragments between 1mm and 1cm orbiting Earth. Of these, almost 37,000 are actively tracked and catalogued.
The urgent need to track end-of-life satellites
There is now an urgent need to improve the real-time tracking of objects, as well as satellite traffic management and identification of methods to remove debris. The means to address the handling of decommissioned satellites by moving them to higher orbits, deorbiting them or finding ways to service and extend their life has become a focus in industry talks recently.
Servicing satellites could also be a path to recycling systems rather than launching a replacement, including refuelling satellites and updates to software and systems to create new uses.
In most cases, satellites remain in orbit despite being inactive for a number of years. The US Federal Communications Commission (FCC) has already proposed that US-based operators either move satellites near the end of life to higher orbits or position them lower so they can be deorbited within five years of completing their missions.
The latter is the required plan for the satellites being placed in low earth orbit (LEO). As more and more satellite constellations are placed into orbit, is a universal agreement on their management a possibility? Can industry leaders and international governments come together and agree to common rules to manage end-of-life for satellites as well as enforce these rules?
Kessler Syndrome: a cause for concern?
In 1978, NASA scientist Dave Kessler proposed the theory that if the density of space debris reaches a critical threshold, it would lead to a chain reaction of collisions in LEO that could envelop the planet in debris. This could further lead to LEO being too congested for satellites to orbit and impact the ability to launch space missions, with consequences resulting in the loss of satellite communications, internet and Global Positioning Systems (GPSs).
If this were to happen, the financial impact would be staggering, leading to commerce slowing if not stopping altogether. Aviation, shipping and loss of the Internet would also impact both commercial and military operations.
A lot has changed since the first shuttle launch. Space has moved from being utilised only by government agencies to now including commercial operators providing launch services and developing satellite constellations in LEO. Naturally, the number of planned satellite constellations is increasing, but to what end?
Starlink’s latest Semi-Annual Constellation Status Report revealed that 24,410 collision avoidance manoeuvres were made to avoid space debris and other satellites between June and December 2023. Now, consider all the satellite constellations planned by other enterprises and countries. The need to track, manage, and manoeuvre these objects in real time has never been more important.
Collaboration and accountability
With the increased tracking of space debris, satellites will need to have the capability to detect and respond to debris with the highest risk of impacting the system near their orbit and without intervention. This includes the requirement and capability to deorbit ageing satellites in LEO and higher orbits.
Several companies have started work on developing active debris removal systems to collect debris. While some have focused on larger pieces, including satellites and rocket launch stages, others are looking at systems to collect smaller items, possibly using nets. However, one crucial question still needs to be addressed. How will this be funded?
Traditionally, the operator pays for end-of-life or systems that have failed. However, when it comes to satellites that have been abandoned when the operator is out of business, it becomes an area of concern.
Satellite communications and other space systems like space stations will need to have the capabilities to detect and, if needed, manoeuvre away from debris. Designers should also consider hardening the systems to handle hits by small pieces or have systems in place that deflect or capture debris. However, it is important to note that the former carries the risk of sending the debris into the path of another satellite or vehicle. Therefore, capture may be the optimal approach.
Plans to manage and track systems in space (satellites, space stations), both government and commercial, will also be needed as space use increases. The United States has transitioned their monitoring programme from the Department of Defence to the Department of Commerce. Several commercial enterprises are also looking into monitoring space traffic.
A means to coordinate worldwide tracking and monitoring will also be needed to provide seamless tracking as is done by air traffic systems.
Another source of debris has been anti-satellite tests. The industry needs to address how the militarisation of space will impact operations of government and commercial systems. As usage expands, more questions arise: can an agreement be reached to discontinue these types of tests? What actions, if any, can be taken if tests are done?
Governments and enterprises will also need to address the impact of bad actors – whether government-sponsored or independent – who are hacking satellites to control operations, spoof data, or change orbits. This will require companies to include cybersecurity as part of their satellite design and possibly the launch providers, including cybersecurity as a requirement for launching a payload. Ideally, companies should incorporate cybersecurity in the infancy of satellite design, and launch providers should include it as a part of the requirements for payload launches.
An international agreement: The final frontier
With more nations and private companies sending payloads such as satellite constellations and space stations into orbit, as well as vehicles travelling to the Moon, Mars and deeper space, the industry needs to come together and address how space debris will be managed and utilised to prevent collisions and wider issues.
It is imperative that all debris is identified, tracked and collected for effective satellite communications. A space traffic management system that all users adhere to is the only answer. How this will be established will need to be the focus of these discussions.
