Orbital Debris and

1
Orbital Debris and
BRIEFING
Collisional Cascading

• Di Carlo T.

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The Problem
Random collisions between man-made objects in
earth orbit may some day initiate cascading
collisions that will exponentially pollute these
high-value orbits, rendering them exceedingly
hazardous for space ventures. As suggested by.
Collisional Cascading - The Limits of Population
Growth in Low Earth Orbit, Kessler, Donald J.,
NASA Doc ID 19920036034, Adv. Space Res. Vol. 11,
No. 12, pp. (12)63-(12)66, 1991
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Sampling of Prior Art
EVOLVE - one-dimensional, LEO-only, deterministic
and stochastic environment evolution model with
Monte Carlo processing (NASA) LEGEND Leo-to-Geo
Environment Debris model, 3-dimensional
(altitude, latitude, longitude) evolutionary
model (NASA) CHAINEE PIB model for long-term
LEO predictions based on traffic assumptions and
mitigation measures (ESA) SDM/STAT like
CHAINEE, based on modulation of background
population (ESA) PIB particle in a box
(1) (1) for a description of PIB see Analytic
Model for orbital Debris Environmental
Management, David L. Talent, Journal of
Spacecraft and Rockets, Vol. 29, No. 4, pp.
508-513, 1992
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NASA Orbital Debris Program Architecture
Source NASA 26 July 2006 Orbital Debris
Environment Presentation to ISS Independent
Safety Task Force
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Sources / Sinks
Satellites 120 launches per year worldwide (but,
emerging China, Japan and India space programs
could inflate this figure double it?) (1)
(2) Rocket Body Parts 2-3 per launch
(1) Spontaneous Explosions, Fragmentations 3
(6), 124 since 1961 (2) Anti-Satellite Tests
(ASAT) Soviet Union, at least 4 between 1968
and 1982 (3) (5) USA, at least 1 in 1985
(Solwind) (4) China, 1 in 2007 Space Warfare
none, yet Random Collisions 1 to date (Cerise,
1996, without explosion) (5)
Natural Decay due to drag, also function of
solar activity DeOrbits and Retrievals policy
options
(1) Analytic Model for orbital Debris
Environmental Management, David L. Talent,
Journal of Spacecraft and Rockets, Vol. 29, No.
4, pp. 508-513, 1992 (2) Office of Science and
Technology, Nov 1995 Interagency Report on
Orbital Debris (3) http//www.nytimes.com/2007/01/
18/world/asia/18cnd-china.html?ex1326776400en3f
5fb4a065572bbbei5088partnerrssnytemcrss (4)
http//en.wikipedia.org/wiki/Anti-satellite_weapon
(5) Survey of past on-orbit fragmentation
events, Carmen Pardini, Acta Astronautica 56
(2005) 379-389 (6) Future Planned Space Traffic
1990-2010 and Beyond, Phillip D. Anz-Meador,
AIAA/NASA/DOD Orbital Debris Conf., April 16-19,
1990, Baltimore MD
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The System
DEBRIS SOURCES
Nations Vying for Space Superiority
Nations Technological Development Nations
Wanting Access to Space New Space Programs
SPONTANEOUS EXPLOSIONS
ANTI-SATELLITE TEST
COLLISIONS
ORBITAL SPACE DEBRIS POPULATION
Solar Flux
DEORBIT, RETRIEVAL
DECAY
DEBRIS SINKS
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200000 Objects in LEO! 1cm or larger
500000 by 2050 (1998 U.N. Committee on Peaceful
Uses of Outer-Space prediction)
Inter-Agency Space Debris Coordination Committee,
43rd Session
http//www.orbitaldebris.jsc.nasa.gov/photogallery
/beehives/LEO1280.jpg
CNES/ill.D.DUCROS,1999
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Conceptual Model
Solar Flux
Decay Block
Collision Block
SSN Catalog
c1
c2
c3
c4
s1
s2
s3
s4
Holding Tanks
1m
10 cm
1cm
1mm
initialization
est. of untrackable objects
w1
w1
g3
g4
w1
w1
g1
g2
New Satellites Input
BreakupBlock
ASAT Input
s1
s2
s3
s4
Exit
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Reference Behavior (measurement)
Number of Catalogued Space Objects (typically 4
in. or larger)
200-300 / yr
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Reference Behavior (simulation)
NASA EVOLVE PROJECTIONS
SOURCE http//www.orbitaldebris.jsc.nasa.gov/news
letter/pdfs/ODQNv10i2.pdf
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Preliminary Extend Model
USER INTERFACE
PIB EQUATION
LEVELS
COEFFICIENTS
COUNTERS, PLOTTERS, AND CONSTANTS
EXCEL INTERFACE
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Particle In a Box Equation
new objects mostly policy-driven
debris sweep rate- a policy measure
crude attempt to model modulating effect of solar
activity
orbit decay crude and semi-empirical
temporary place-holder, suggesting dependence on
altitude
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Notional User Interface
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Extend Deposition Sub-Model
Number of significant fragments generated per
explosion (could be stochastic)
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Extend Removal Sub-Model
Extend Excel INTERFACE
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Extend Collisions Sub-Model
Number of significant fragments generated per
collision (could be stochastic)
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Extend ?? Excel
Extend Global Array Managers
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1-Tier, 1-Species
Altitude Range 350 1800 km
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4-Tier, 1-Species (to be implemented)
500-800 km
800-1500 km
1500-2000 km
200-500 km
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Critical Simplifying Assumptions
De-Orbit Algorithm crude, based on average
debris diameter, which is turn estimated a
function of on-orbit mass, number of orbiting
objects, and the simplifying assumption that
objects are spherical and of uniform
density. Solar Flux Prediction I assume a
repeating 21 cycle may be critical for
longer-term predictions Number of Pieces per
explosion 120, could be stochastic Number of
Fragments per collision 200, could be stochastic
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Preliminary Extend Results (1957-2010)
Solar Activity (F10) and Orbital Decay (N_out)
Solar Activity (Jansky)
Decay (number/year)
Simulation Year
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Preliminary Extend Results (1957-2010)
Significant Objects in Low Earth Orbit (N)
Significant Objects in LEO
Simulation Year
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Preliminary Extend Results (1957-2010)
Satellite Kill Rate (rough estimate)
Collision Coefficient (C)
SAT Kill Rate (/yr)
Simulation Year
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Preliminary Insights
Will Collisional Cascading Occur? - maybe, but
Im not seeing it yet (N tends to level
out) Policy and Design they DO make a
difference, for example - post-mission disposal
of upper stages reduces N 20 - Doubling SAT
density (packaging) reduces N 20
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Forward Work
NEAR-TERM
Validation match reference behaviors
get/implement Kesslers input Sensitivity
Analysis screen for critical parameters and
fine tune them 4-Tier, 1-Species Implementation
if time allows (for granularity)
LONG-TERM
Historical Satellite Database link to database
Implement as a Discrete Event n-Tier, n-Species
Simulation Simplify user Interface using Extend
Notebook
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Summary
Simulation of orbital accumulation Inspired by
1991 paper describing idea of Collisional
Cascading AKA The Kessler Syndrome
Resources, Reference Behaviors Extend6
Simulation Development Environment SSN Catalog
published historical trends loads of studies and
published papers Don Kessler Implementation P
article-in-a-Box Continuous Simulation
Model Extend??Excel User Policy
Interface Potential Benefits, and Lessons to be
Learned Dynamics of orbital crowding Conditions
for Collisional Cascading Space as a
Sustainable Resource
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Publications and Resources
(1) Collisional cascading - The Limits of
Population Growth in Low Earth Orbit, Kessler,
Donald J., NASA Doc ID 19920036034 (2) Littered
Skies, NYTimes.com, 6 Feb 2007,
http//www.nytimes.com/2007/02/06/science/20070206
_ORBIT_GRAPHIC.html?_r2orefsloginorefslogin (
3) Overview of Orbital Space Debris, IPS Radio
and Space Services, www.ips.gov.au/Educational/4/2
/1 (4) Space Simulation and Modeling - Roles and
Applications Throughout the System Life Cycle,
Larry B. Rainey editor, The Aerospace Press, El
Segundo CA, 2002 (5) Simulation Model of Space
Station Operations in the Space Debris
Environment, Mark M. Mekaru and Brian M.
Waechter, Proceedings of the 1985 Winter
Simulation Conference (6) Collisions of
Artificial Earth Orbiting Bodies, L. Sehnal and
L. Pospisilova, Publishing House of the
Czechoslovak Academy of Sciences, 18 Nov 1980 (7)
Orbital Debris Environment Resulting from Future
Activities in Space, Shin-Yi Su, Center for Space
and Remote Sensing Research and the Department of
Atmospheric Physics, National Central University,
Chung-Li, P.R.C., Taiwan, 23 Oct 2002 (8) The New
NASA Orbital Debris Engineering Model,
NASA/TP2002-210780, May 2002 ORDEM2000www.orbital
debris.jsc.nasa.gov/library/ORDEM/ORDEM2K.pdf