Show that the satellite's orbital period P at large distances (r a) is given by

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SUMMARY

The discussion focuses on deriving the orbital period P of a satellite in a circular orbit at large distances, specifically when r >> a. The expression for P is given by P = [(4π/GM)^(1/2)] r^(3/2) (1 - (3/4)((a^2)/(4r^2)) J2). The relevant equations include the gravitational acceleration g = (GM/(a^2))[-1 - (3/2) J2] and the relationship between angular velocity and gravitational force. The behavior of P as r approaches infinity indicates that the influence of J2 diminishes, leading to a simplified orbital period.

PREREQUISITES
  • Understanding of gravitational physics and orbital mechanics
  • Familiarity with the concept of orbital periods and circular motion
  • Knowledge of the gravitational constant G and mass M of celestial bodies
  • Basic understanding of perturbation effects in orbital dynamics, specifically J2
NEXT STEPS
  • Study the derivation of Kepler's Third Law for circular orbits
  • Explore the effects of J2 on satellite orbits and perturbation theory
  • Learn about the implications of orbital mechanics in astrodynamics
  • Investigate numerical methods for simulating satellite orbits under perturbations
USEFUL FOR

Astronomy students, aerospace engineers, and physicists interested in satellite dynamics and orbital mechanics will benefit from this discussion.

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Homework Statement



Assuming that the satellite's orbit is circular, show that its orbital period P at large distances (r>>a) is given by the expression:

P=[(4pi/GM)^(1/2)] r^(3/2) (1-(3/4)((a^2)/(4r^2)) J(subscript2))

Comment on the behavious of P in the limits as r approaches infinity

2relevant equations

g=(GM/(a^2))[-1-(3/2) J(subscript2)]

The Attempt at a Solution



omega^2 r =(GM/(a^2))(-1-(3/2)J(subscript 2))

(2pi/T)^2=(GM/(a^2))(-1-(3/2)J(subscript 2))

T=((4pi^2)/GM)^(1/2) sqrt [((a^2)r)/(m-(3/2)J2 -1)]
 
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sorry I meant

T=((4pi^2)/GM)^(1/2) sqrt [((a^2)r)/(-(3/2)J2 -1)]

the 'm' in what I wrote before is not supposed to be there
 


behaviour typo
 

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