Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks...
-
Upload
priscila-turnock -
Category
Documents
-
view
217 -
download
0
Transcript of Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks...
![Page 1: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/1.jpg)
Orbital PertubationsOrbital Pertubations
![Page 2: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/2.jpg)
AtmosphereOrbital Decay
Effect of the AtmosphereEffect of the Atmosphere
Height (km) Life
200 2 weeks
1000 1000yrs
36000 1Myrs
![Page 3: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/3.jpg)
Effect of the Earth’s ShapeEffect of the Earth’s Shape
TOP VIEWTOP VIEW SIDE VIEWSIDE VIEW
15m15m
15m15m
7.5m7.5m 7.5m7.5m
EQUATOREQUATOR
12 714 km12 714 km
12 756 km12 756 km
N Pole
![Page 4: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/4.jpg)
Orbital PertubationsOrbital PertubationsThese are subtle but accumulative effect on an orbit
• Nodal regression• The orbital plane effectively twists around the earth• This is because of the shape of the Earth. • This effect is known as Orbital Twist.
• Perigee Rotation• This effect appears as a twisting of the satellites position
relative to the Equator.• Therefore, satellites need to be managed, in effect ‘flown’.
![Page 5: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/5.jpg)
Applications of OrbitsApplications of Orbits• LEO
• Earth Observation with resolution• Communications
• MEO Missions• Global Navigation Satellite Systems
• GEO • Communications• Earth Observation with persistence
• HEO • Communications• Earth Observation with persistence
![Page 6: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/6.jpg)
Persistence………Persistence………
![Page 7: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/7.jpg)
………….versus Resolution.versus Resolution
![Page 8: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/8.jpg)
Orbital RequirementsOrbital Requirements
LEO
Coverage
Dwell Time
Revisit Time
Resolution & Power Requirements
GEO c.700
![Page 9: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/9.jpg)
Achieving OrbitAchieving Orbit
![Page 10: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/10.jpg)
Initial LaunchInitial Launch
Direct ascent into low altitude orbit
![Page 11: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/11.jpg)
Data TableData TableEarth Gravitational
Force Mass of Earth Radius of Earth Orbital Height Orbital Velocity Orbital Period Energy Required to Achieve Orbit
6.67E-11 5.98E+24 6.378E+06 12 7900.7 84.7 3.133E+07
6.67E-11 5.98E+24 6.378E+06 19 7896.3 84.9 3.136E+07
6.67E-11 5.98E+24 6.378E+06 100 7846.8 86.5 3.175E+07
6.67E-11 5.98E+24 6.378E+06 200 7786.9 88.5 3.222E+07
6.67E-11 5.98E+24 6.378E+06 300 7728.4 90.5 3.267E+07
6.67E-11 5.98E+24 6.378E+06 400 7671.2 92.6 3.311E+07
6.67E-11 5.98E+24 6.378E+06 500 7615.2 94.6 3.354E+07
6.67E-11 5.98E+24 6.378E+06 600 7560.5 96.7 3.396E+07
6.67E-11 5.98E+24 6.378E+06 700 7506.9 98.8 3.436E+07
6.67E-11 5.98E+24 6.378E+06 800 7454.4 100.9 3.475E+07
6.67E-11 5.98E+24 6.378E+06 900 7403.0 103.0 3.514E+07
6.67E-11 5.98E+24 6.378E+06 1000 7352.7 105.1 3.551E+07
6.67E-11 5.98E+24 6.378E+06 1100 7303.3 107.3 3.587E+07
6.67E-11 5.98E+24 6.378E+06 1200 7255.0 109.4 3.622E+07
6.67E-11 5.98E+24 6.378E+06 20000 3888.6 710.6 5.498E+07
6.67E-11 5.98E+24 6.378E+06 35789 3075.6 1436.3 5.781E+07
![Page 12: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/12.jpg)
Hohman Transfer OrbitHohman Transfer Orbit
Initial Orbit
Transfer Orbit
Final Orbit
![Page 13: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/13.jpg)
On Orbit On Orbit ManoeuvreManoeuvre Basics Basics
• Attain initial on-orbit station.• Maintain assigned position (all Geo satellites).• Modify orbit to meet new mission requirements.
On-board motors (“thrusters”) are fitted to modify the satellite’s orbit to:
![Page 14: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/14.jpg)
RepositioningRepositioning
• Primarily for GEO satellites .• Using fuel shortens life.• Takes weeks or months to complete the manoeuvre.• Takes capability away from users.
Moving satellite to a higher or lower orbit:
![Page 15: Orbital Pertubations. Atmosphere Orbital Decay Effect of the Atmosphere Height (km) Life 2002 weeks 10001000yrs 360001Myrs.](https://reader031.fdocuments.net/reader031/viewer/2022020306/551c2c9c5503469e4f8b6128/html5/thumbnails/15.jpg)
Skynet 5A Launch SimulationSkynet 5A Launch Simulation