Today’s Space Elevator: Assured Survivability Approach for Space Debris

The International Space Elevator Consortium's (ISEC) position has been well documented and discussed. Space elevator activities concerning space debris were initiated in the 2010 ISEC Study Report, "Space Elevator Survivability, Space Debris Mitigation" after a full year of analyses by space debris and space systems experts. Since then, there have been events that have increased the growth of space debris. The 2020 report re-examines the situation and extrapolates across the arena to arrive at some preliminary results. The numbers were calculated for the present (2019 tracked debris data), and compared to past (2010 data), and future (2030 estimates with projections of new satellite constellations). The approach, as discussed in the 2010 space debris report, is one in which the volume of space around the Earth is shown to have a density of debris related to altitude zones. That report identified and examined the zones, analyzed the information and presented conclusions. The collision probability analyses are linear with respect to numbers of debris within the volume occupied by a 100,000 km long by one-meter wide tether. The real efforts focused upon high debris density regions with identified zones between 200 and 2000 km altitudes. This report takes the density numbers, extrapolates the probabilities of collision and arrives at conclusions. The Executive Summary of 2010 Report stated: "To assess the risk to a space elevator, we have used methodology from the 2001 International Academy of Astronautics (IAA) Position Paper on Orbital Debris.

With discussions and calculations across three decades, the conclusion is the same for time periods 2010, 2019 and 2030 :

"Space debris mitigation is an engineering problem with definable quantities such as density of debris and lengths/widths of targets. With proper knowledge and good operational procedures, ... space debris is not a show-stopper by any means. However, mitigation approaches must be accepted and implemented robustly."