On July 12, 2019, the Department of National Defence (DND) presented a call to help develop a viable and cost-effective way to track and de-orbit space debris[1]. With the rapid growth in the space industry projected over the next decade, the call comes at a critical point where accumulated space debris has raised the risk of collision for existing and planned satellites. This is becoming especially important given the rise of so-called mega-constellations, where the number of operational satellites is predicted to rise from less than 2,000 to more than 20,000 in the next decade. The question that normally accompanies these discussions is this: why, in the context of competing government priorities and resources, would Canada allocate valuable resources to removing space debris? The Space Debris Problem Orbital debris represents a growing threat to the operation of satellites. According to ESA’s Space Debris Office, there are currently hundreds of thousands of debris objects greater than one centimeter in diameter in Earth’s orbit, and approximately 128 million objects between one centimetre and one millimeter[2]. The U.S. Space Surveillance Network (SSN) operates a catalogue that routinely tracks more than 21,000 orbiting items larger than 10 centimeters in the orbits from Low Earth Orbit (LEO) to Geostationary Orbit (GEO). These objects, the vast majority of which are classified as debris, are mostly the remnants of space objects such as defunct satellites, discarded rocket stages, and debris created by collisions between space objects. Before 2007, the primary source of space debris was the explosion of old launch-vehicle upper stages. Upper stages are used to give satellites the final kick into the desired orbit and were most often left to slowly drift back down to Earth. However, these rocket bodies had a small remnant of fuel. Often, these rocket bodies would explode due to the heating of the enclosed propellant and material fatigue.[3] However, because of the growth of commercial and private space activity, it is anticipated that debris will increase over the next few years, despite the international debris mitigation guidelines. According to one review on the state of space debris published in Science, “[i]n reality, the situation will undoubtedly be worse because spacecraft and their orbital stages will continue to be launched.”[4] The key element of the space debris problem is the increase in the space object population in LEO. As the number of objects grows, the greater the chance for collisions increases, risking a cascade of collisions. This effect is referred to as the “Kessler Syndrome” and was famously portrayed in popular culture by the movie Gravity. In addition, the higher the altitude, the longer the space debris will remain in orbit. Orbital debris below 600 kilometers returns to Earth and burns up within several years. However, at altitudes of 800 kilometers or higher, the orbital decay lasts decades, with debris not expected to fall back to Earth before a century or more. Space operators can expect a sharp increase in the number of conjunction warnings as the number of catalogued objects increases. According to a presentation made at the Military Space Surveillance conference in London, England this past February, the Combined Space Operations Center, operated by the USAF, issued 6.7 million satellite conjunction alerts last year. In addition, the Combined Space Operations Center only provides conjunction warnings on objects larger than 10 centimeters.  Impact with an object 1 centimeter or larger will cause damage likely to destroy a satellite[5], and yet objects of this size cannot be reliably tracked. Therefore, there is a large latent risk from unobserved debris with the highest risk to operational satellites coming from lethal and non-trackable debris. (In)Famous Debris Creation Events There are three prominent...