diff --git a/CLAUDE.md b/CLAUDE.md
index 321ec53..b2e49ae 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -7,7 +7,6 @@
 ## Architecture
 - C-style C++ (structs/functions, NO classes/templates)
 - Raylib (git submodule) for 3D - chose over SFML (no 3D support)
-- See docs/verbose_project_overview.md for detailed technical architecture
 - See docs/implementation_plan.md for data structures reference
 
 ## Coding Rules
diff --git a/Makefile b/Makefile
index 27a7e09..9f10a77 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ TEST_TARGET = orbit_test
 # Source files
 CPP_SOURCES = $(SRC_DIR)/main.cpp \
                $(SRC_DIR)/physics.cpp \
-               $(SRC_DIR)/bodies.cpp \
+               $(SRC_DIR)/simulation.cpp \
                $(SRC_DIR)/config_loader.cpp \
                $(SRC_DIR)/renderer.cpp
 
@@ -86,12 +86,12 @@ test-build:
 	$(CXX) $(CXXFLAGS) \
 		-c $(SRC_DIR)/physics.cpp -o build/test_physics.o
 	$(CXX) $(CXXFLAGS) \
-		-c $(SRC_DIR)/bodies.cpp -o build/test_bodies.o
+		-c $(SRC_DIR)/simulation.cpp -o build/test_simulation.o
 	$(CXX) $(CXXFLAGS) \
 		-c $(SRC_DIR)/config_loader.cpp -o build/test_config_loader.o
 	$(CC) -Wall -Wextra -g -ggdb3 -std=c99 -I./src -I./ext/tomlc17/src \
 		-c $(SRC_DIR)/../ext/tomlc17/src/tomlc17.c -o build/test_tomlc17.o
-	$(CXX) build/test_main.o build/test_integration.o build/test_energy.o build/test_orbital_period.o build/test_comet_orbit.o build/test_utilities.o build/test_physics.o build/test_bodies.o build/test_config_loader.o build/test_tomlc17.o \
+	$(CXX) build/test_main.o build/test_integration.o build/test_energy.o build/test_orbital_period.o build/test_comet_orbit.o build/test_utilities.o build/test_physics.o build/test_simulation.o build/test_config_loader.o build/test_tomlc17.o \
 		-o $(TEST_TARGET) -lCatch2Main -lCatch2 -lm
 
 # Run automated test suite
diff --git a/docs/implementation_plan.md b/docs/implementation_plan.md
index 5f699b1..9ec771d 100644
--- a/docs/implementation_plan.md
+++ b/docs/implementation_plan.md
@@ -18,7 +18,7 @@ struct Vec3 {
 };
 ```
 
-### CelestialBody (bodies.h)
+### CelestialBody (simulation.h)
 ```cpp
 struct CelestialBody {
     char name[64];
@@ -34,7 +34,7 @@ struct CelestialBody {
 };
 ```
 
-### SimulationState (bodies.h)
+### SimulationState (simulation.h)
 ```cpp
 struct SimulationState {
     CelestialBody* bodies;
@@ -55,7 +55,7 @@ struct RenderState {
 };
 ```
 
-### OrbitalElements (bodies.h)
+### OrbitalElements (simulation.h)
 ```cpp
 struct OrbitalElements {
     double time_days;
@@ -82,7 +82,7 @@ struct AccelerationContext {
 ### Physics (physics.cpp/h)
 Vector math and gravity calculations. RK4 (Runge-Kutta 4th order) integration with `rk4_step()`.
 
-### Bodies (bodies.cpp/h)
+### Simulation (simulation.cpp/h)
 Simulation state management and updates. SOI detection using Hill sphere: `r_soi = a * (m/M)^(2/5)`.
 
 **Key functions:**
diff --git a/docs/session_summaries/2026-01-04-refactor-orbital-elements.md b/docs/session_summaries/2026-01-04-refactor-orbital-elements.md
index 592951c..799f582 100644
--- a/docs/session_summaries/2026-01-04-refactor-orbital-elements.md
+++ b/docs/session_summaries/2026-01-04-refactor-orbital-elements.md
@@ -3,8 +3,8 @@
 ## Changes Made
 
 Refactored orbital elements calculation from test-specific to reusable code:
-- Moved `OrbitalElements` struct from test file to `src/bodies.h`
-- Moved `calculate_orbital_elements()` function to `src/bodies.cpp`
+- Moved `OrbitalElements` struct from test file to `src/simulation.h`
+- Moved `calculate_orbital_elements()` function to `src/simulation.cpp`
 - Created `tests/test_comet_orbit.cpp` with SOI transition tracking
 - Added `ParentChange` tracking to detect when comet switches gravitational parent
 - Removed `tests/test_soi_transitions.cpp` (not useful for detecting actual transitions)
diff --git a/src/config_loader.h b/src/config_loader.h
index ee3aecd..42c3542 100644
--- a/src/config_loader.h
+++ b/src/config_loader.h
@@ -1,7 +1,7 @@
 #ifndef CONFIG_LOADER_H
 #define CONFIG_LOADER_H
 
-#include "bodies.h"
+#include "simulation.h"
 #include "../ext/tomlc17/src/tomlc17.h"
 
 // Load a system configuration from a file (TOML format)
diff --git a/src/main.cpp b/src/main.cpp
index 7071925..57b656e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,5 @@
 #include "physics.h"
-#include "bodies.h"
+#include "simulation.h"
 #include "config_loader.h"
 #include "renderer.h"
 #include <cstdio>
diff --git a/src/physics.cpp b/src/physics.cpp
index 6e85768..fe32d23 100644
--- a/src/physics.cpp
+++ b/src/physics.cpp
@@ -1,5 +1,5 @@
 #include "physics.h"
-#include "bodies.h"
+#include "simulation.h"
 #include <cmath>
 
 // Vector addition
diff --git a/src/renderer.h b/src/renderer.h
index 7f1ed73..7519c4f 100644
--- a/src/renderer.h
+++ b/src/renderer.h
@@ -1,7 +1,7 @@
 #ifndef RENDERER_H
 #define RENDERER_H
 
-#include "bodies.h"
+#include "simulation.h"
 #include "raylib.h"
 
 // Rendering state
diff --git a/src/bodies.cpp b/src/simulation.cpp
similarity index 99%
rename from src/bodies.cpp
rename to src/simulation.cpp
index 2446cc0..9ec652e 100644
--- a/src/bodies.cpp
+++ b/src/simulation.cpp
@@ -1,4 +1,4 @@
-#include "bodies.h"
+#include "simulation.h"
 #include <cstdlib>
 #include <cstring>
 #include <cstdio>
diff --git a/src/bodies.h b/src/simulation.h
similarity index 100%
rename from src/bodies.h
rename to src/simulation.h
diff --git a/src/test_utilities.h b/src/test_utilities.h
index d351c72..cd532d5 100644
--- a/src/test_utilities.h
+++ b/src/test_utilities.h
@@ -1,7 +1,7 @@
 #ifndef TEST_UTILITIES_H
 #define TEST_UTILITIES_H
 
-#include "bodies.h"
+#include "simulation.h"
 #include "physics.h"
 
 struct OrbitalMetrics {
diff --git a/tests/test_comet_orbit.cpp b/tests/test_comet_orbit.cpp
index fd27c73..46e593b 100644
--- a/tests/test_comet_orbit.cpp
+++ b/tests/test_comet_orbit.cpp
@@ -1,6 +1,6 @@
 #include <catch2/catch_test_macros.hpp>
 #include "../src/physics.h"
-#include "../src/bodies.h"
+#include "../src/simulation.h"
 #include "../src/config_loader.h"
 #include "../src/test_utilities.h"
 #include <cmath>
diff --git a/tests/test_energy.cpp b/tests/test_energy.cpp
index 19e9fae..a773374 100644
--- a/tests/test_energy.cpp
+++ b/tests/test_energy.cpp
@@ -1,6 +1,6 @@
 #include <catch2/catch_test_macros.hpp>
 #include "../src/physics.h"
-#include "../src/bodies.h"
+#include "../src/simulation.h"
 #include "../src/config_loader.h"
 #include "../src/test_utilities.h"
 #include <cmath>
diff --git a/tests/test_orbital_period.cpp b/tests/test_orbital_period.cpp
index fa491c6..7ebf2f7 100644
--- a/tests/test_orbital_period.cpp
+++ b/tests/test_orbital_period.cpp
@@ -1,6 +1,6 @@
 #include <catch2/catch_test_macros.hpp>
 #include "../src/physics.h"
-#include "../src/bodies.h"
+#include "../src/simulation.h"
 #include "../src/config_loader.h"
 #include "../src/test_utilities.h"
 #include <cmath>