# 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/


remaining todo
 - Review planned model expansion
 - Reformulate bellman residual minimization to use Q and M
 - Get code working, and run a basic analysis (proto kessler regions)
