Orbital Mechanics Essentials

Orbital mechanics, or astrodynamics, involves the motion of spacecraft under the influence of gravitational forces. It's key for mission design, navigation, and predicting satellite positions.

Spacecraft orbits follow Newton's laws of motion and universal gravitation. An object in orbit is in freefall, constantly 'falling' towards Earth but moving forward enough to miss it.

Orbits are categorized by shape and orientation: circular, elliptical, parabolic, hyperbolic; and by altitude: LEO, MEO, GEO, HEO. Each serves different functions, like communication or observation.

Delta-V is the change in velocity needed to alter an orbit. It’s a crucial concept in mission planning, requiring efficient propulsion systems to execute orbital maneuvers.

Lagrange points are five positions where a small object affected by two larger celestial bodies’ gravity can maintain a stable position relative to them, useful for spacecraft positioning.

Real orbits experience perturbations due to non-uniform Earth's gravity, solar pressure, and atmospheric drag. Precise tracking and occasional thruster burns correct these deviations.

Interplanetary missions use Hohmann transfer orbits to move between planets efficiently. They require impeccable timing to utilize planetary alignments, minimizing fuel consumption.