Aerobraking

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Aerobraking
Mollie Devoe
Wells College
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Agenda

• What is Aerobraking?
• How Aerobraking works
• Aerobraking Simulation
• Results
• Programs future

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Setting the Stage
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What is Aerobraking?

• Aerobraking is a technique to transform an
  elliptical orbit into a circular orbit
• Aerobraking exploits a planets atmosphere to
  perform a controlled drag maneuver.

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How Aerobraking Works

• Atmospheric molecules strike the spacecraft
  transferring energy and momentum.
• The momentum transfer creates drag which
  aerobrakes the spacecraft.

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Types of Aerobraking

• Single-Pass

• Multi-Pass

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Phase 1 Walk-in

• Propulsive maneuvers gradually drop the
  spacecrafts periapsis
• This allows evaluation of the vehicles response
  to the new environment in gradually increasing
  levels

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Phase 2 Main Phase

• A series of small propulsive maneuvers keep
  periapsis in control corridor

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Phase 3 Endgame

• Desired circular orbit is met
• Propulsive maneuvers raise periapsis out of
  atmosphere to stop aerobraking

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Project Goals

• To understand orbital mechanics
• -calculate an orbit from initial conditions
• -understand the effects of drag
• Build a program that simulates aerobraking

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About the Program

• Application parameters
• -planet mass, planet radius, spacecraft mass,
• time lapse
• Current position
• -x, y, r, theta, velocity, net force...
• Updates current position, including total energy
  and angular momentum

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Two Dimensional Integration

• Choose coordinate system
• -Origin at planets center
• Position is a function of x and y

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Velocity at Specific Position
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Therefore the New Position After dt is...

• In x direction

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What About the Change in Velocity?
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The New Velocity After dt is...
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Running the Program

• Simulations run with the following initial
  velocities
• - 0 m/s
• - 1200 m/s
• - 1250 m/s
• - 1275 m/s
• - 1280 m/s
• - 1300 m/s

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A Closer Look...
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The Programs Future

• Run more simulations to gain a better
  understanding of drag
• Three dimensional integration
• Apply to other planets

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Acknowledgments

• Professor Scott Heinekamp
• Professor Carol Shilepsky
• Frank Lacomb