diff --git a/src/orbital_objects.h b/src/orbital_objects.h
index c3ec70d..191ed63 100644
--- a/src/orbital_objects.h
+++ b/src/orbital_objects.h
@@ -4,13 +4,8 @@
 #include "physics.h"
 #include "orbital_mechanics.h"
 
-// Forward declarations
-struct SimulationState;
 
-// ============================================================================
 // Rendezvous Types
-// ============================================================================
-
 enum RendezvousState {
     RENDEZVOUS_NONE,
     RENDEZVOUS_PLANNING,
@@ -20,7 +15,8 @@ enum RendezvousState {
     RENDEZVOUS_FAILED
 };
 
-struct RendezvousTarget {  // Active rendezvous target configuration
+// Represents a spacecraft or probe in the simulation.
+struct RendezvousTarget {
     int target_index;           // Index of target spacecraft/body
     RendezvousState state;      // Current rendezvous state
     double approach_distance;   // Distance to start approach phase (m)
@@ -30,10 +26,10 @@ struct RendezvousTarget {  // Active rendezvous target configuration
     bool is_spacecraft_target;  // True if target is spacecraft, false if body
 };
 
-// ============================================================================
-// Celestial Body Structure
-
-struct CelestialBody {  // Gravitational body in the simulation
+// Represents a planet, star, moon, or other gravitational body in the
+// simulation. Supports hierarchical orbital mechanics with parent-child
+// relationships and sphere of influence calculations.
+struct CelestialBody {
     char name[64];
     double mass;              // kg
     double radius;            // meters