# Intro Why do we care Possible stories: sep 2019 2020 - 3 near misses with ISS (https://www.jpost.com/science/international-space-station-nearly-struck-by-chinese-satellite-debris-684809) (https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv24i3.pdf) May 2020 - Fregat tank breakup (left debris from 1000 to 6000 miles in altitude) May 2021 - Canadarm2 got hit (https://www.asc-csa.gc.ca/eng/iss/news.asp, part way down) Nov 2021 - Dodge debris from anti-satellite test in 2007 (China) (Jerusalem post above) Nasa releases a Monday Nov 15, 2021 - ISS astronauts have to shelter in their exit craft due to a debris cloud nearing the ISS. (https://www.space.com/space-debris-astronauts-shelter-november-2021) (https://www.youtube.com/watch?v=m-LIh0fdfq8) - from youtube: limits the set of experiments they can work with. Maybe explain the whole section. Why should we care? - All orbits are subject to some degree of polution. - Common uses: GPS, Military Communications, Commercial internet and TV. - Exploratory uses: R&D of pharmaceuticals, exploration. - Collisions and debris damage are to some degree inevitable. - Kessler Syndrome What is different now: - Launch costs (https://aerospace.csis.org/data/space-launch-to-low-earth-orbit-how-much-does-it-cost/) (https://fortune.com/2017/06/17/spacex-launch-cost-competition/) - Cubesats/nanosats (numbers at https://www.nanosats.eu/) - in short, accessability. With lower cost per mass to orbit, more reasons to go. With lower development costs, easier to build many small satellites. This gives us a need for urgency. - Anti-Satellite missles (US, RU, CH all have capability) - Starlink vs Kupiter vs OneWeb (UK gov) # Present previous literature Rao Rondina - Major results: exploitation of common pool resource Adilov et al - Major results: Exploitation of common pool resource Adilov et al - Major results: Divergence between economic and non-economic kessler syndromes # my model - Kessler Syndrome work - Model description # Solution methods - Issues - High dimensionality - Many Firms, Governments, and other organizations (How many different operators currently?) - Interacting debris fields between orbits (see the Fregat breakup) - Approximation is required - state space discretization - Not sure which states to examine - fuctional approximation - Maliar - Reinforcemnt learning - Choice of using NN approach - Well supported on hardware - Transfer learning - # Analysis # major points - Summaries of results so far. - Request for suggestions on utility functions that might be worth investigating - Discussion of goals - Investigate pigouvian taxation, cleanup bonds, etc. - Standardize interface so it is easy to estimate results. - - Discussion of other work that should happen - Estimation of parameters (simulation, bayesian, calibration, best guesstimates, etc) - Rights of way work (way to get operators to declare a no-move value?) - Satellite Lifetime Management and it's impact on decision making. (nested overlapping generations?) Other sources Historical breakup events: https://www.orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv23i1.pdf Breakups: https://www.orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv25i1.pdf Newsletter on debris breakups: https://www.orbitaldebris.jsc.nasa.gov/quarterly-news/