Calculateur d'Énergie Orbitale Spécifique

Calculez l'énergie orbitale spécifique d'un objet en orbite.

m
kg

Specific Orbital Energy

-29,432,232 J/kg

Specific Orbital Energy vs Semi-Major Axis

Voir la formule →

Formule

Specific Orbital Energy

epsilon = -G M / (2a)

  • Negative energy = bound (elliptical) orbit
  • Zero = parabolic escape
  • Positive = hyperbolic trajectory

    • This quantity is constant along the entire Keplerian orbit.

    Exemple Résolu

    ISS orbit with semi-major axis a = 6 771 km around Earth.

    1. 01epsilon = -G M / (2a)
    2. 02G M = 3.986e14
    3. 032a = 1.354e7
    4. 04epsilon = -3.986e14 / 1.354e7 ≈ -29.4 MJ/kg

    Questions Fréquentes

    Why is bound orbit energy negative?

    The gravitational potential energy (negative) exceeds the kinetic energy, so the total is negative and the body cannot escape.

    How does energy relate to orbit shape?

    Energy depends only on the semi-major axis, not eccentricity. A circle and an elongated ellipse with the same a have the same energy.

    What happens at exactly zero energy?

    The orbit is parabolic, corresponding to escape velocity at every point.

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