Transcript Long-term Evolution of High Area-to

Long-term Evolution of High Area-to-Mass
Ratio Objects in Different Orbital Regions
T. Schildknecht, A. Vananti, A. Hinze
Astronomical Institute, University of Bern, Switzerland
PEDAS1-0017-12
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore,
India
Astronomical Institute University of Bern
Slide 2
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Outline
1. The AIUB/ESA HAMR Catalogue
2. Orbit Evolution in GEO & MEO
3. Summary
Astronomical Institute University of Bern
Catalogue of Small-Size Space Debris


Build-up and maintenance of orbit catalogue of
decimeter-sized debris in GEO/GTO/MEO
Why?
 Density/collision risk lower than in LEO
BUT:
No sinks  population constantly grows
 Mitigation of debris is important
Need to know nature and sources of debris
Requires:
 Orbit catalogue
 Constant monitoring due to perturbations by
non-gravitational forces
Astronomical Institute University of Bern
Slide 3
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
1-m ZIMLAT
Switzerland
Astronomical Institute University of Bern
Slide 4
Sensors
1-m ESA Telescope
Tenerife

Discover new objects: Obs. From Tenerife (OGS, AIUB)

Secure orbits: obs. from OGS, Zimmerwald (AIUB)

Maintain orbits: obs. from OGS, Zimmerwald, international
partners, International Scientific Optical observation Network
(ISON), ...
 Daily orbit maintenance at AIUB and Keldysh Institute of
Applied Mathematics of the Russian Academy of Sciences
(KIAM)
 Orbit catalogue of high-altitude space debris

Provide predictions:
 To other partners (CNES, JAXA, NASA, Roscosmos...)
  to investigate physical properties of objects
Astronomical Institute University of Bern
Slide 5
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
High AMR GEO/GTO Catalogue
ESA 2008 GEO/GTO Surveys
Detections (Jan 2008 - Dec 2008)
60
2
correlated
uncorrelated
Sensitivity 99
50
1.8
40 cm
1.6
15 cm
1.4
40
1.2
60 cm
30
1
0.8
20
10 cm
correlated
Sensitivity
0.6
0.4
10
0.2
uncorrelated
0
0
9
10
11
12
13
14
15
16
17
18
19
20
21
Magnitude
Astronomical Institute University of Bern
Slide 6
Frequency
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Continuous program, ~80 nights per year
Orbital Elements (Jan 2002 - Jan 2012; elliptical orbits)
22
20
correlated
uncorrelated
18
16
14
12
10
8
6
4
2
0
-180
-120
-60
0
60
120
180
R.A. of Ascending Node [°]
Slide 7
Inclination [°]
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
6-param. Orbits - i vs Ω
Astronomical Institute University of Bern
“Routine” ZIMLAT Support
ZIMLAT Observation Statistics
Observation Nights
ZIMLAT
Observation Nights
200
Observation Nights
160
140
120
100
80
60
40
20
0
10.02 –
09.03
10.03 –
09.04
10.04 –
09.05
10.05 –
09.06
10.06 –
09.07
10.07 –
09.08
10.08 –
09.09
10.09 –
09.10
10.10 –
09.11
ZIMLAT Observation Statistics
Years
400
35,000
Objects
Observations
30,000
300
25,000
250
20,000
200
15,000
150
10,000
100
5,000
50
0
0
10.02 – 10.03 – 10.04 – 10.05 – 10.06 – 10.07 – 10.08 – 10.09 – 10.10 –
09.03
09.04
09.05
09.06
09.07
09.08
09.09
09.10
09.11
Years
Astronomical Institute University of Bern
Slide 8
ZIMLAT
Observations / Objects
Observations (tracklets)
350
Objects
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
180
High AMR GEO/GTO Catalogue
0.8
0.7
UCT: 1218 CT: 184
0.6
0.5
uncorrelated
correlated
vapo = 15"/s
vapo = 10.5"/s
vapo = 7.5"/s
vapo = 5"/s
e(n)=1-rp*n^(2/3)/mu^1/3
e(n)=ra*n^(2/3)/mu^1/3-1
0.4
0.3
0.2
0.1
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Mean Motion [rev/d]
Astronomical Institute University of Bern
5
Slide 9
Eccentricity
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Eccentricity vs Mean Motion (Jan 2002 - Jan 2012; elliptical orbits)
High AMR GEO/GTO Catalogue
180
160
140
120
100
standard office paper
80
60
40
20
0
0
4
8
12
16
20
24
28
32
36
Area to Mass Ratio [m2/kg]
40
44
48
52
56
Max. 86.7 m2/kg
Astronomical Institute University of Bern
Slide 10
Frequency
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Area-to-Mass Ratio (345 Uncorrelated Objects)
Slide 11
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Outline
1. The AIUB/ESA HAMR Catalogue
2. Orbit Evolution in GEO & MEO
3. Summary
Astronomical Institute University of Bern
Methodology
Assumption
 There are sources of high AMR debris when
objects are left in space for long time span (aging
processes, breakup-events, ...)

Question
 What are the impacts for the concept of
"graveyard" orbits

Method
 Propagate orbits of a sample of observed debris
over a time interval of 50 years assuming
different AMR values (0.02, 0.02, 1, 5, 15 m 2/kg).
Astronomical Institute University of Bern
Slide 12
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Propagator
CelMech SATORB Propagator
 numerical integrator (variable step size)
 12 x 12 Earth gravity field
 gravitational perturbations from
• Sun
• Moon
• Earth tides
 corrections due to general relativity
 direct radiation pressure (Sun only)
 eclipses (Earth, Moon)
Slide 13
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Astronomical Institute University of Bern
Sample of super-GEO Objects
Sample of 30 debris objects in super-GEO region
 a > 42464km (>300km above GEO)
 e < 0.05; then set to 0.001
 t0 = 55000mjd
(2009-06-18)
Orbital Elements
(Jan 2002 - Jan 2012; elliptical orbits)
22
20
uncorrelated
18
16
14
12
10
8
6
4
2
0
-180
-120
-60
0
60
120
180
R.A. of Ascending Node [°]
Slide 14
Inclination [°]
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Astronomical Institute University of Bern
Slide 15
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Semimajor Axis
Astronomical Institute University of Bern
Slide 16
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Eccentricity
Astronomical Institute University of Bern
Slide 17
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Perigee Height
Astronomical Institute University of Bern
Slide 18
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Orbital Plane
Astronomical Institute University of Bern
GEO Graveyard
Objects in GEO graveyard orbits (>300km above
GEO) will cross GEO altitude if AMR>0.2m2/kg
 will also cross 0° GEO region for particular
inclination/argument of perigee combinations
 orbital plane and argument of perigee are both
changing over time
 precession of orbital planes not significantly
changed for AMR<5m2/kg

Consistent with IADC deorbit guideline:
ΔHmin = 235 + 1000*cr*AMR [km]
 435km for AMR=0.2m2/kg
Astronomical Institute University of Bern
Slide 19
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Sample of super-GPS/GLONASS Objects
Sample of super-GPS objects (14)
 a > 27400km (>900km above GPS)
 all orbital elements at actual values
 t0 = 55000mjd (2009-06-18)

Sample of GLONASS objects in plane G2 (11)
 a ≈ 25508km
 all orbital elements at actual values
 t0 = 55000mjd (2009-06-18)
Slide 20
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Astronomical Institute University of Bern
Slide 21
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Semimajor Axis
Astronomical Institute University of Bern
Slide 22
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Eccentricity (GPS)
Astronomical Institute University of Bern
Slide 23
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Eccentricity (GLONASS)
Astronomical Institute University of Bern
Slide 24
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Perigee Height (GPS)
Astronomical Institute University of Bern
Slide 25
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Perigee Height (GLONASS)
Astronomical Institute University of Bern
Slide 26
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India
Evolution of Orbital Plane
Astronomical Institute University of Bern
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India



Strong gravitational perturbations of GPS orbits due
to 2:1 mean motion resonance
 eccentricity
 inclination, precession of orbital plane
Objects in GPS graveyard orbits (>900km above
GPS) will cross GPS altitude if
 AMR ≳ m2/kg
OR
 e(t0) ≳ 0.01
Perigee height of GLONASS orbits will change by
>1000km if
 AMR ≳ 1m2/kg
Astronomical Institute University of Bern
Slide 27
GPS/GLONASS Orbits
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India


Catalogue of high AMR GEO/GTO objects
 significant debris population with high AMR found in GEO
and GTO region
 orbits maintained by sharing the data in a network of
observatories (KIAM, ISON)
GEO/MEO graveyards
 sources of high AMR debris to be expected when objects
are left in space for long time span (aging processes,
breakup-events, ...)
 objects in GEO graveyard (300km above GEO) will cross GEO
altitude if AMR>0.2m2/kg
 perigee height of objects in GPS/GLONASS orbits will
change for >1000km if AMR≳1m2/kg
 long-term evolution of GPS orbits dominated by
gravitational resonance effects for e(t0) ≫ 0.01
Astronomical Institute University of Bern
Slide 28
Conclusions
Acknowledgments

Great thanks to our staff and observers at the OGS
and Zimmerwald observatories!
Support in the form observations to maintain the
orbits is provided by the Keldysh Institute of Applied
Mathematics (KIAM) in the framework of the ISON
collaboration (AIUB-KIAM collaboration).
Slide 29
T. Schildknecht: Long-term Evolution of High Area-to-mass Ratio Objects
39th COSPAR Scientific Assembly, 14 - 22 July, 2012, Mysore, India

Astronomical Institute University of Bern