The Next 100 Years Projection of Debris in GEO Space Systems Dynamics Laboratory Yuya Mimasu 1st March, 2007

The Next 100 Years Projection of Debris in GEO

Space Systems Dynamics Laboratory Yuya Mimasu

1st March, 2007

Contents

BackgroundObjectiveModeling ConceptProjection ScenarioResult of ProjectionSummary

BackgroundGeosynchronous Earth Orbit (GEO) is the most valuable resource, and many satellites have been launched into this region.

At present, Collision Hazard due to traffic jam is a serious issue.

Mitigation MeasuresMeasurementModelingProtectionMitigation Debris Environment around Earth

Objective

We project the next 100 years by repeating insertion of the 8-year traffic for the years 1998 through 2005 as one cycle of projection by using GEODEEM.

GEODEEM is GEO Debris Environmental Evolutionary Model developed at Kyushu University.

Modeling Concept

Initial ConditionTraffic at 1st January 2006 Annual Number of Actual

Launches in 1998

Annual Number of Actual Disposed Satellites in 1998

Traffic at 2007Annual Number of Actual Launches in 1999

Annual Number of Actual Disposed Satellites in 1999

Traffic at 2008

..... Repeat during 100 years

Insertion Data

Explosions

Collisions

Explosions

Collisions

Explosion is occurred because of residual propellant or some failures.

Category

Space objects are categorized according to their longitude stability as shown in following table.

Categories Longitude Stability GEO crossing

Operational Satellite Constant Yes

Abandoned Satellite Librating/Oscillating Yes

Disposed Satellite Drifting No

Rocket Body Drifting No

Fragments crossing GEO Drifting Yes

Fragments staying above/under GEO

Drifting No

Operational Satellites

Disposed Satellites

Abandoned Satellites

Post Mission

Launch

Rocket BodiesEarth

Accumulation Process

Normal Process

Geostationary Ring

Orbit more than 300 km above GEO

Operational Satellites

Disposed Satellites

Abandoned Satellites

Launch

Rocket BodiesEarth

Accumulation ProcessCollision

orExplosion

Geostationary Ring

Orbit more than 300 km above GEO

Initial Population

Population of each category at initial state

Category X1 X2 X3 X4 X5 X6

Number 344 125 282 218 251 74

X1: Operational Satellites

X2: Abandoned Satellites

X3: Disposed Satellites

X4: Rocket Bodies

X5: Fragments crossing GEO

X6: Fragments staying above/under GEO

Propagator

The propagator is adopted to the DebrisPerturbations

Earth’s gravitational Attraction Third Body (Sun and Moon)Solar Radiation Pressure

Solution

Analytical Solution

Collision ProbabilityCollision Probability is calculated by

using following equation.

121221

12 UAV

p

V

VpC

EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...EPSFçÏê¨íÜ...

P

S

d/2

r

d/2

d = desired distance tolerance r = distance between objects

Nodal line

t: time that the object spends in the spherep1 , p2: probabilities that objects will be in sphere during one revolutionP: orbital period, V: volume of sphereV: volume of overlapping portion

A12: sum of representative area of two objects,

Projection Scenario

Economical and Political situation does not change from present state.

The increasing tendency of space objects will not change in 100 years.

Assumption

ScenarioProject from 1st January 2006 with 8-year traffic for the years 1998 through 2005 as one cycle of projection.

Business as usual

Results of Projection

Projection without Disposal Projection with Actual Disposal

The Number of Collisions in 30 Monte Carlo run

Rocket BodyDisposedSatellite Abandoned

Satellite OperationalSatellite

Operational Satellite

Abandoned Satellite

Disposed Satellite

Rocket Body

0

1

2

3

4

5

6

7

8

9

10

Rocket BodyDisposedSatellite Abandoned

Satellite OperationalSatellite

Operational Satellite

Abandoned Satellite

Disposed Satellite

Rocket Body

0

1

2

3

4

5

6

7

8

9

10


Satellite

Rocket Body

S10

2

4

6

8

10

12

The Number of Explosions

Satellite

Rocket Body

S10

2

4

6

8

10

12

The Number of Explosions


The Average Number of Explosions in 30 Monte Carlo run



Population of Space Objects in Several Categories

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60 70 80 90 100Time (years)

Popu

latio

n

X1: Operational Satellite

X2: Abandoned Satellite

X3: Disposed Satellite

X4: Rocket Bodies


X6: Fragments staying above/ under GEO

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60 70 80 90 100Time (years)

Popu

latio

n

X1: Operational Satellite

X2: Abandoned Satellite

X3: Disposed Satellite

X4: Rocket Bodies


X6: Fragments staying above/ under GEO


2006

2026

2046

2066

2086

2106

Year

1000

500

0

500

Alt. from GEO km0

500

1000

# objects

0

500

1000

# objects

2006

2026

2046

2066

2086

2106

Year

1000

500

0

500

Alt. from GEO km0

500

1000

# objects

0

500

1000

# objects


Distribution of Population of Space objects > 10 cm

Summary

Modification in this study Update Initial Condition. Update Launch History. Inserted Traffic of Actual Disposed Satellite.

Conclusions Although the disposed satellites lead to a decrease of

population on GEO and collision probability, the population of debris do not change dramatically.

To decrease the hazard of debris, we need to decrease the number of explosions.

ご清聴ありがとうございました．

(Goseityou Arigatou Gozaimasita)

Documents

The Next 100 Years Projection of Debris in GEO Space Systems Dynamics Laboratory Yuya Mimasu 1st March, 2007