Dominic Ernst, Omar Abdel-Wahab Orbital Mechanics

Post on 17-Apr-2022

18 views 0 download

Transcript of Dominic Ernst, Omar Abdel-Wahab Orbital Mechanics

Orbital MechanicsDominic Ernst, Omar Abdel-Wahab

Orbital mechanics

IntroductionInto OrbitTo Marsand beyond…

Why Orbital Mechanics? Introduction Into Orbit To Mars and beyond…

Understanding of celestial movementsIt’s awesome!For Science!…and convenience

Orbital velocity Introduction Into Orbit To Mars and beyond…

How fast are you moving?A: 0 km/hB: 1600 km/h C: 25 km/sD: 225 km/sE: well, it depends…à Concept of relative velocity

Kepler’s LawsIntroduction Into Orbit To Mars and beyond…

The Orbit of an Object is an ellipse with the heavy body in one centerSpeed is proportional to distance from centerOrbital period is proportional to orbital radius

Conservation of EnergyIntroduction Into Orbit To Mars and beyond…

 

Orbital mechanics

IntroductionInto OrbitTo Marsand beyond…

Into Orbit Introduction Into Orbit To Mars and beyond…

Vertical componentHorizontal componentOrbitsRocket Launch

Vertical component Introduction Into Orbit To Mars and beyond…

https://www.kennedyspacecenter.com/events/events-calendar/see-a-rocket-launch

Into Orbit Introduction Into Orbit To Mars and beyond…

Vertical componentHorizontal componentOrbitsRocket Launch

Horizontal component Introduction Into Orbit To Mars and beyond…

But Earth‘s surface iscurved!

Horizontal component Introduction Into Orbit To Mars and beyond…

Horizontal component Introduction Into Orbit To Mars and beyond…

Horizontal component Introduction Into Orbit To Mars and beyond…

Gravitational force

Centripetal force

Horizontal component Introduction Into Orbit To Mars and beyond…

Velocity needed for Orbitaround Earth

Into Orbit Introduction Into Orbit To Mars and beyond…

Vertical componentHorizontal componentOrbitsRocket Launch

OrbitsIntroduction Into Orbit To Mars and beyond…

Low Earth Orbit – LEOMedium Earth Orbit – MEOGeostationary Earth Orbit – GEOothers...

OrbitsIntroduction Into Orbit To Mars and beyond…

Low Earth Orbit – LEOMedium Earth Orbit – MEOGeostationary Orbit – GEOothers...

https://en.wikipedia.org/wiki/Low_Earth_orbit#/media/File:Orbitalaltitudes.jpg

OrbitsIntroduction Into Orbit To Mars and beyond…

Low Earth Orbit – LEOMedium Earth Orbit – MEOGeostationary Orbit – GEOothers...

https://en.wikipedia.org/wiki/Low_Earth_orbit#/media/File:Orbitalaltitudes.jpg

OrbitsIntroduction Into Orbit To Mars and beyond…

Orbit Height Velocity Period Used for

LEO 200 - 1'500 km 7.1 - 7.8 km/s

1.5 - 5 h Earth observationSpace stations (ISS)Communication

MEO 6'000 - 12'000 km

5.6 - 4.7 km/s

5 - 12 h Navigation (GPS)Communication

GEO 35'786 km 3.07 km/s 23h 56min 4s

Communication Weather observation TV broadcast (Astra, Eutelsat)

Graveyard Orbit

ca. GEO + 300km < GEO > GEO Disposed satellites

OrbitsIntroduction Into Orbit To Mars and beyond…

Orbit Height Velocity Period Used for

LEO 200 - 1'500 km 7.8 - 7.1 km/s

1.5 - 5 h Earth observationSpace stations (ISS)Communication

MEO 6'000 - 12'000 km

5.6 - 4.7 km/s

5 - 12 h Navigation (GPS)Communication

GEO 35'786 km 3.07 km/s 23h 56min 4s

Communication Weather observation TV broadcast (Astra, Eutelsat)

Graveyard Orbit

ca. GEO + 300km < GEO > GEO Disposed satellites

Into Orbit Introduction Into Orbit To Mars and beyond…

Vertical componentHorizontal componentOrbitsRocket Launch

Rocket LaunchIntroduction Into Orbit To Mars and beyond…

https://www.grc.nasa.gov/www/k-12/rocket/rktrflght.html

Orbital mechanics

IntroductionInto OrbitTo Marsand beyond…

Hohmann Transfer Introduction Into Orbit To Mars and beyond…

Orbital maneuver with minimal energy requirement (Δv)Increase Apoapsis to target Orbit

Hohmann Transfer Introduction Into Orbit To Mars and beyond…

Going from Earth to Mars takes ~8 monthWhen can we go?

Other problems Introduction Into Orbit To Mars and beyond…

Orbit of Mars is inclined & elliptical

Orbital mechanics

IntroductionInto OrbitTo Marsand beyond…

and beyond…Introduction Into Orbit To Mars and beyond…

Limits by:CostFeasibilityTime

and beyond…Introduction Into Orbit To Mars and beyond…

MethodsHohmann transfersGravitational slingshotFuzzy orbits

Hohmann transferIntroduction Into Orbit To Mars and beyond…

https://de.wikipedia.org/wiki/Hohmann-Transfer

Gravitational Slingshot Introduction Into Orbit To Mars and beyond…

Also: Swing-by or Gravity assist1961: Michael MinovitchFirst application:

Mariner 10 (1973): to Mercury via Venus

Gravitational Slingshot Introduction Into Orbit To Mars and beyond…

Steal orbital energy of a planetChange speed and trajectory of spacecraft(Almost) no fuel needed

Gravitational Slingshot Introduction Into Orbit To Mars and beyond…

https://en.wikipedia.org/wiki/Gravity_assist

Gravitational Slingshot Introduction Into Orbit To Mars and beyond…

https://saturn.jpl.nasa.gov/resources/1776/

Cassini-Huygens

Gravitational Slingshot Introduction Into Orbit To Mars and beyond…

https://en.wikipedia.org/wiki/Gravity_assist#/media/File:Cassini%27s_speed_related_to_Sun.png

Fuzzy orbitsIntroduction Into Orbit To Mars and beyond…

Even lower-cost-paths possiblePaths between Lagrange points of planets

Low cost, but often very slowLot of computation necessaryFuture: high-volume, low-value goods

https://en.wikipedia.org/wiki/Interplanetary_Transport_Network#/media/File:Interplanetary_Superhighway.jpg

Orbital mechanics

Questions?

Want to learn more?

Play «Kerbal Space Program»https://kerbalspaceprogram.com/en/