1. NASA Orbital Debris Quarterly, Volume 22, Issue 4, November 2018. https://orbitaldebris.jsc.nasa.gov/quarterly-news/newsletter.html/.
2. Union of Concerned Scientists database: https://www.ucsusa.org/nuclear-weapons/space-weapons/satellite-database#.XFSD9FVKjmF.
3. ORDEM 3.1 development status;Anz-Meador,2018
4. Space Fence: https://www.lockheedmartin.com/en-us/products/space-fence.html.
5. Tracking requirements in LEO for space traffic management in the presence of proposed small satellite constellations;Peterson,2018