OPS-G Forum: Recent in-orbit fragmentations and their impact

Recent In-orbit Fragmentations and their impact | Krag | 28.08.2009 | Pag. 1

Recent In-orbit Fragmentations and their Impact

OPS-G Forum Presentation

Holger KragOPS-GR

Aug. 28th, 2009

Special acknowledgements to: Tim Flohrer, Benjamin Bastida Virgili, Raymond Choc


– Introduction

– ESA’s Collision Avoidance Service

– Procedure and principles

– Operational examples

– Major Fragmentation Events

– FY-1C ASAT (January 11th, 2007)

– Briz-M break-up (February 19th, 2008)

– USA-193 interception (February 21st, 2008)

– Iridium-Cosmos collision (February 10th, 2009)

– Consequences of these events

– Consequences for ESA satellites

– Long-term impact on the environment

Contents


Contents

Introduction


The US Space Surveillance Network

DIEGOGARCIA

NSSSCAPE COD

LSSCBEALE

KAENA PT.

FYLINGDALESCLEAR

SCC

THULE

CAVALIER

MAUI & MSSS

ALTAIR

SOCORRO

ASCENSION

EGLIN

MOSS

Discovery Radar

Tracking Radar

Optical Telescope

MSX / SBV

COBRA DANE

GLOBUS II

DIEGOGARCIA

NSSSCAPE COD

LSSCBEALE

KAENA PT.

FYLINGDALESCLEAR

SCC

THULE

CAVALIER

MAUI & MSSS

ALTAIR

SOCORRO

ASCENSION

EGLIN

MOSS

Discovery Radar

Tracking Radar

Optical Telescope

MSX / SBV

COBRA DANE

GLOBUS II

Coverage: Objects > ca. 10cm in LEO


0

2000

4000

6000

8000

10000

12000

14000

16000

19571960 1970 1980 1990 2000 2009

Num

ber

of o

bjec

ts

Catalogued Objects in Orbit as of August 2009

The US SSN Object Catalogue

1958 1964 1970 1976 1982 1988 1994 2000 2006

Nu

mb

er o

f o

bje

cts

0

2000

4000

Payloads

Rocket Bodies

Fragments

Other6000

12000

14000

16000

10000

8000

Public US object catalogue as of August 2009


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140

0 100 200 300 400 500 600 700 800

Fre

quen

cy [-

]

Number of catalogued objects per event [-]

Severity of past events

1400

Pegasus HAPSAriane 1 R/B

2600

Cosmos/Iridium Collision FY-1C ASAT

Ca. 250 fragmentation events


Consequences

Mean time between impacts on a surface of 100m2

Valid for May 2005Altitude >0.1mm >1mm >1cm >10cm

400km 4.5 days 3.9 years 1,214 years 16,392 years

800km 2.3 days 1.0 years 245 years 1,775 years

1,500km 0.9 days 1.5 years 534 years 3,190 years

GTO 16.8 days 17.7 years 7,650 years 96,591 years

GEO 78.1 days 264 years 154,006 years 414,749 years

4 known cases


ESA’s Collision Avoidance Service


Conjunction Analysis Process

FlightDynamicsFlightDynamics

OperatorsOperators FlightDynamicsFlightDynamics

Chaser orbits and covariance data;

CRASS configuration

ODINODIN

Orbit tracks

Solar & geomag. activity data

CRASSCRASS DISCOSDISCOS

LEO

MEO+GEO System Architectural Overview

US Space Surveillance Network

TLEs


Orbit Accuracy and Collision Avoidance

– Data required to describe and qualify an orbit:

– Orbit state vector or ephemeris

– Metrics for the quality of the orbit fit: Covariance

Instead of exact conjunction geometry, only a collision probability can be determined

(not precise for TLEs)

(not available for TLEs)

Chaser

Target


TLE Orbit Uncertainty Estimation

0 10 20 30 40 50 60 70 80 90 100 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0

2000

4000

6000

8000

10000

Eccentricity [-]Inclination [deg]

1-si

gma

unce

rtai

nty

[m]

Estimate out-of-plane component of TLE covariance

– Approach applied at ESA consists of a comparison of the TLE orbit with an accurate numerical orbit resulting from a least-squares fit of the TLE orbit

– ± 0.5days from TLE epoch

– State at epoch and drag coefficient estimates


Determination of collision probability

– Determination of combined target+chaser cross section

– Combination of the two error covariance matrices into a single one (3D ellipsoid)

– Projection of ellipsoid onto the B-plane

– ║distance vector

– ┴ relative velocity vector

– Integration of projected probability over cross-section = collision probability

Rt

RrAC

B-plane

AC

Combined position error ellipsoid

θ

Δvtca

Δrtca


Automated reporting

– Automatic compilation of a bulletin for ten highest risk conjunction events and distribution by email.

Conjunction geometry

Chaser approach geometry

Target + chaser orbital elements

Combined orbit uncertainties

Chaser object properties


Improvement of Chaser Orbit Information

Monge tracking ship

Tracking and Imaging Radar

?!

EISCAT radars

??

GRAVES


– Due to the improved orbit information (ca. 4m x 21m x 13m) the collision typically decreases to a negligible level:

Improvement of Chaser Orbit Information (2/2)

AC

p(Δr)


Operational Examples

1.) 09.01.2008, 19:00 UTC: Envisat vs. Cosmos-1624

– Bulletin: Collision probability : 1/1172, Distance: 499m

– With FGAN-Tracks: Collision probability : ~0, Distance: 282m

2.) 13.01.2008, 18:58 UTC: Envisat vs. Cosmos-1371


– With FGAN-Tracks: Collision probability : 1.5E-26, Distance: 145m

3.) 05.03.2008, 03:35 UTC: ERS2 vs. Formosat 3-C


– With Operational Data: Collision probability : 8.2E-5, Distance: 1.193m

4.) 23.04.2009, 03:29 – 26.04., 08:35 UTC: Envisat vs. Cosmos-3M (71 conjunctions)


– With USSTRATCOM support: smallest miss distance: 499m


Recent Major Events


FY-1C ASAT (1/4)

Physical properties Mass 958 kg Span 1.4m Length 1.4m Width 8.6m

Orbit at event epoch Semi major axes 7231.43 km Eccentricity .00036 Inclination 98.645°

– Feng Yun 1C (“Wind & clouds”) – Chinese weather satellite, launched 1999

– Satellite was intercepted by a Dong Feng type missile on January 11th – “kinetic kill”

Feng Yun 1C

Dong Feng


– Backward propagation of the first 32 published fragment orbits

– At event epoch, fragment come close to parent position

Positions of fragments and parent object

Epoch (UTC)

J an, 11, 2007, 22:25:55 (+/- 20s)

Latitude 35,16° Longitude 100.36° Altitude 863 km

Event epoch

FY-1C ASAT (2/4)


March 2006,

18th-21st

June 2007,

4th-7th

Time [d]

Impact of Jan. 11 ASAT test

EISCAT Svalbard radar (lon: 16.029°, lat: 78.153°)

(42m and 32m UHF antennas)

FY-1C ASAT (4/4)


Briz-M break-up (1/2)

Physical properties Dry Mass 2,370 kg Total Mass 22,170 kg Fuel/Oxidizer UDMH/NTO

Orbit at event epoch Semi major axes 13978.63 km Eccentricity 0.50798 Inclination 51.49°

– Briz-M (or Breeze-M) – maneuverable space tug used as 4th stage for Proton-M

– On February 28, 2006, due to a malfunction, the Briz-M stranded in an elliptical orbit (with Arabsat 4A)

– Since only about 24% of the available Δv has been consumed at least half of the hypergolic propellant was left (about 10t)

Briz-M


Epoch (UTC)

Feb, 19, 2007, 17:11:00 (+/-20s)

Latitude -39,39° Longitude 124.62° Altitude 5920 km

– Reconstruction of the event: Optical observations from Australia

– Half hour exposure (16:50 to 17:17 UTC on February 19) from Chittering, Western Australia, at 31° 27' S, 116° 06' E

– Simulation results with ESA’s PROOF (Program for Radar and Optical Observation Forecasting)

Briz-M break-up (2/2)


USA-193 interception (1/2)

Epoch Feb 21st, 03:29 UTC Semi Major Axis 6636.040 km Inclination 58.532° RAAN 30.127°

– Classified experimental military satellite launched December 14th, 2006, malfunctioned shortly after launch

– Without any further interaction, the satellite would have performed an uncontrolled re-entry at around March 11th, 2008.

– Due to concerns of the US government on the possible survival of tanks that contain toxic hydrazine the satellite was intercepted with the help of a ballistic missile

NOTAM Area

03:29

0

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No

rth

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latit

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e [

de

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Western longitude [deg]

Amateur TLE


Iridium-Cosmos collision (1/4)

Common Name I ridium 33 Catalog Number 24946 COSPAR ID 1997-051C Launch Date Sep. 14th, 1997 Mass 661 kg Dimensions 4.1m x 1.0m x 8.4m

Common Name Cosmos 2251 Catalog Number 22675 COSPAR ID 1993-036A Launch Date J un. 16th, 1993 Mass 892 kg Dimensions ?m x ?m x ?m



Epoch Feb. 10th 2009, 16:55:59.80 UTC

Event Altitude 788.68km Longitude 97.88° Latitude 72.51°

Iridium

Cosmos

Δv=11.647km/s


– Two objects tagged with the COSPAR IDs of Iridium 33 and Cosmos 2251 are still tracked by the US Space Surveillance Network (main fragments)?

7160

7162

7164

7166

7168

7170

7172

7174

31 02 04 06 08 10 12 14 16

Se

mi M

ajo

r A

xis

[km

]

Time in February [DD]

IridiumCosmos 2251

86.39

86.392

86.394

86.396

86.398

86.4

86.402

31 02 04 06 08 10 12 14 16 74.044

74.045

74.046

74.047

74.048

74.049

74.05

74.051

Incl

ina

tion

Irid

ium

[d

eg

]

Incl

ina

tion

Co

smo

s 2

25

1 [

de

g]

Time in February [DD]

IridiumCosmos 2251



– EISCAT Svalbard measurements (Cosmos 2251 fragments are not observable)

– The second zenital passage at around 07:00 UTC is less pronounced



Consequences of these events


US SSN Screening Process

– Detection and Cataloguing of all detectable fragments is a time consuming process

0

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3000

2007 2008 2009

Num

ber

of F

ragm

ents

FY-1C fragments

Collision fragments

Initially seen


Modelling break-ups (1/2)

– Fragmentation modelling with the help of the EVOLVE break-up model

– The model uses a power-law distribution for N(>d) to be scaled with the number of catalogued fragments

0.01

1

100

10000

1e+006

1e+008

1e+010

1e+012

1e-006 1e-005 0.0001 0.001 0.01 0.1 1 10

Cum

ula

tive

nu

mbe

r of

obj

ects

> d

Characteristic length / Diameter [m]

Explosion - 100 trackable objects

Collision - target: 800kg- impactor: 200kg


Calibration of the model

Henize factor

1

1.5

2

2.5

3

3.5

0.001 0.01 0.1 1H

eniz

e F

acto

r [-

]Diameter [m]

Example: FY-1C ASAT

– For immediate risk assessment the initially reported number needs to be scaled with the Henize factor

After 2 years of screening

1

10

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100000

1e+006

1e+007

0.001 0.01 0.1 1 10

Cu

mu

lativ

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d)

Diameter [m]

US Surv. Netw.ASAT Modelling Approach


Comparison to measurements (1/2)

– Plane dispersion: COSMOS is faster than Iridium

– Comparison: EISCAT / PROOF: EISCAT is looking at pinch points

EISCAT Svalbard RadarPinch point

Situation 150 days later


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ber

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etec

tions

[-]

Time [h of day]

Comparison to measurements (2/2)

EISCAT Svalbard: March 13th, 2007

Show movie


Results: FY-1C ASAT

Directly after event

> 10cm 1,329 > 1cm 59,427 > 1mm 2,852,910

Gabbard diagram - modelled

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Apo

gee/

Per

igee

Alti

tude

[km

]

Orbital Period [min]

PerigeeApogee

517 fragments (TLEs)

TLE


Results: Briz-M break-up



> 10cm 1,156 > 1cm 46,6445 > 1mm 1,820,250

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25000

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Ap

oge

e/P

erig

ee A

ltitu

de [k

m]


PerigeeApogee


Results: USA-193 interception


> 10cm 1,773 > 1cm 69,216 > 1mm 2,896,860

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gee/

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[km

]


PerigeeApogee



– Object passes as seen in a horizontal coordinate system from the CSG site:

– Black lines: modelled objects

– Red lines: catalogued objects

– With progressing time, due to Earth rotation, the launching site will move out of the range of the fragment orbit planes into Eastern direction at a rate of 15° in longitude per hour

USA 193 fragments as seen from ELA3 site from 03:28 to 05:28

West

North

East

South

0

45

90

USA 193 fragments as seen from ELA3 site from 04:28 to 04:38

West

North

East

South

0

45

90

Assumed launch azimuth

Launch Collision Risk for ATV due to USA-193 fragments

T T+10minutes T-1h T+1hT = 2008/03/08 04:28 UTC


Results: Iridium-Cosmos collision

Iridium 33 Cosmos 2251


> 10cm 1,435 > 1cm 61,168 > 1mm 2,963,800

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4500

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Ap

og

ee

/Pe

rige

e A

ltitu

de

[km

]


PerigeeApogee

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og

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/Pe

rige

e A

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[km

]


PerigeeApogeeTLETLE


Results at event epochs

Spatial density for objects > 1cm

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1e-007

2e-007

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5e-007

6e-007

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9e-007

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Spa

tial D

ensi

ty [1

/km

**3]

Altitude [km]

Background 2006FY-1C ASAT

Briz-M break-upUSA-193 interception

Iridium-Cosmos collision


Results 1 month after event epochs


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1e-007

2e-007

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Spa

tial D

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/km

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Results 1 year after event epochs


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1e-007

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ensi

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/km

**3]

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Results 10 years after event epochs


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1e-007

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Spa

tial D

ensi

ty [1

/km

**3]

Altitude [km]


Briz-M break-upIridium-Cosmos collision


Risk increase level - today

Total Collision ASAT > 10cm 17% 12% 1% > 1cm 23% 16% 4%

Contribution to the overall collision risk


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Ris

k in

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[%

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Objects > 1cmObjects > 10cm

ISS

ERS-2 / ENV


Risk increase level – in 10 years

Contribution to the overall collision risk



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Ris

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[%

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ISS

ERS-2 / ENV


Decay profiles

Number of objects > 1cm

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70000

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Num

ber

of o

bjec

ts [-

]

Years after event epoch [-]

FY-1C ASATBriz-M break-up

USA-193 interceptionIridium-Cosmos collision


Consequences for the future environment (1/2)

Evolution of the number of objects >10cm

Scenario:

- no future launches

- no explosions

10000

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12000

13000

14000

15000

16000

17000

2000 2050 2100 2150 2200

Num

ber

of o

bjec

ts [-

]

Epoch

without recent major eventswith recent major events


Consequences for the future environment (2/2)

Evolution of the number collision events

Scenario:

- no future launches

- no explosions

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Num

ber

of c

olli

sion

s [-

]

Epoch

without recent major eventswith recent major events


Impact on Collision Avoidance

– 2006

– Envisat, number of conjunction events with collision probability > 10-6: 81

Payloads37%

Rocketbodies22%

Debris41%



– 2008

– Envisat, number of conjunction events with collision probability > 10-6: 125

Payloads22%

Rocketbodies15%

Debris45%

Fengyun18%



– 2009

– Envisat, number of conjunction events with collision probability > 10 -6: (projected) 327Payloads

4%

Rocketbodies21%

Debris17%

Fengyun9%

Collision49%


Conclusions

– The last two years have seen 4 unprecedented break-up events leading to the release of more than 1000 objects > 10cm each

– Two of the events (FY-1C ASAT, Iridium-Cosmos collision) have a considerable impact on ESA’s Earth observation missions, they lead to a long-term collision risk increase by about 50%

– The consequences are visible and verifiable in ESA’s daily conjunction screening process

– Fragment orbits are typically more difficult to predict and to track, which generates additional burdens on the conjunction analysis efforts

– These events will put a long-term effect onto the existing environment, and (although not changing the trend) will increase the future collision rate

Technology

OPS-G Forum: Recent in-orbit fragmentations and their impact