updates

examples/hypsotest.py

@@ -0,0 +1,94 @@
+"""Hypso 1 test: 1-month deorbit simulation without oxide calculations."""
+
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+import numpy as np
+
+from src import Satellite, Simulation, SimulationConfig, State
+from src.constants import EARTH_GRAVITATIONAL_PARAMETER, EARTH_RADIUS
+from src.environment.atmosphere import Nrlmsise00Density
+from src.events import DeorbitEvent, TimeLimitEvent
+from src.forces import AtmosphericDrag, GravityGradientTorque, NewtonianGravity
+from src.visualization import visualize_orbit
+
+
+def get_default_stl_path() -> Path | None:
+    repo_root = Path(__file__).parent.parent
+    stl_file = repo_root / "sattelite.stl"
+    return stl_file if stl_file.exists() else None
+
+
+def main():
+    stl_path = get_default_stl_path()
+    sat = Satellite(
+        mass=7.6,
+        drag_area=0.06,
+        drag_coefficient=2.2,
+        min_drag_area=0.06,
+        max_drag_area=0.06,
+        stl_path=stl_path,
+        name="hypso 1",
+    )
+
+    altitude = 436_880
+    expected_altitude = 395_977
+    six_months = 182.625 * 86400
+
+    r = EARTH_RADIUS + altitude
+    v = np.sqrt(EARTH_GRAVITATIONAL_PARAMETER / r)
+
+    state = State(
+        position=np.array([r, 0, 0]),
+        velocity=np.array([0.0, v, 0.1]),
+        time=0.0,
+        rotation_euler=np.array([0.5, 0.8, 0.3]),
+        angular_velocity_vec=np.array([1e-4, 1e-4, 1e-4]),
+        temperature_atmosphere=300.0,
+        temperature_sattelite=280.0,
+        oxide_thickness=0.0,
+    )
+
+    atmosphere = Nrlmsise00Density()
+
+    forces = [
+        NewtonianGravity(),
+        AtmosphericDrag(atmosphere),
+        GravityGradientTorque(stiffness=1e-10, damping=0.01),
+    ]
+
+    events = [
+        DeorbitEvent(),
+        TimeLimitEvent(max_time=six_months),
+    ]
+
+    print(f"Hypso 1 - {altitude / 1000:.2f} km initial altitude")
+    print(f"Simulating for 6 months ({six_months / 86400:.1f} days)...")
+    sim = Simulation(
+        state,
+        sat,
+        forces,
+        events,
+        SimulationConfig(dt=3.0, save_interval=500),
+    )
+    sim.run()
+
+    final_alt_km = sim.final_state.altitude() / 1000
+    expected_km = expected_altitude / 1000
+    diff_km = final_alt_km - expected_km
+
+    print(f"\nFinal altitude:      {final_alt_km:.3f} km")
+    print(f"Expected altitude:   {expected_km:.3f} km")
+    print(f"Diff:                {diff_km:+.3f} km")
+    print(f"Sim time:            {sim.final_state.time / 86400:.2f} days")
+    print(f"Steps:               {sim.step_count}")
+
+    if len(sim.history) > 1:
+        print("\nOpening 3D visualization...")
+        visualize_orbit(sim.history, sat, title="Hypso 1 Deorbit")
+
+
+if __name__ == "__main__":
+    main()

flake.nix

@@ -89,9 +89,9 @@
             echo "Python: $(python --version)"
             echo ""
             echo "Run examples with:"
-            echo "  python examples/basic_simulation.py    # Deorbit simulation"
-            echo "  python examples/deorbit_simple.py      # With scheduled changes"
-            echo "  python examples/orbit_comparison.py    # Parallel comparison"
+            echo "  python examples/basic_simulation.py    # Deorbit simulation with 3D visualization"
+            echo "  python examples/hypsotest.py           # Hypso 1 6-month deorbit simulation"
+            echo "  python examples/oxide_simulation.py    # Oxide layer growth simulation"
             echo ""
           '';
         };