From c4b11f1dfbbd56c0d271b890d89a420f24f7c5bf Mon Sep 17 00:00:00 2001
From: Mark Stephenson <mark2000stephenson@gmail.com>
Date: Wed, 1 Oct 2025 22:52:14 -0600
Subject: [PATCH] [MINOR] Make deorbit radius configurable

---
 src/bsk_rl/sim/dyn/base.py          | 10 ++++++++--
 tests/unittest/sim/test_dynamics.py |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/bsk_rl/sim/dyn/base.py b/src/bsk_rl/sim/dyn/base.py
index 362b7b14..5dd81b9f 100644
--- a/src/bsk_rl/sim/dyn/base.py
+++ b/src/bsk_rl/sim/dyn/base.py
@@ -317,6 +317,7 @@ def _setup_dynamics_objects(self, **kwargs) -> None:
         vN=None,
         oe=random_orbit,
         mu=orbitalMotion.MU_EARTH * 1e9,
+        min_orbital_radius=(orbitalMotion.REQ_EARTH + 200) * 1e3,
     )
     def setup_spacecraft_hub(
         self,
@@ -330,6 +331,7 @@ def setup_spacecraft_hub(
         rN: Optional[Iterable[float]],
         vN: Optional[Iterable[float]],
         mu: float,
+        min_orbital_radius: float,
         priority: int = 2000,
         **kwargs,
     ) -> None:
@@ -352,6 +354,7 @@ def setup_spacecraft_hub(
             mu: Gravitational parameter (used only with ``oe``).
             rN: [m] Initial inertial position.
             vN: [m/s] Initial inertial velocity.
+            min_orbital_radius: [m] Minimum allowable orbital radius.
             priority: Model priority.
             kwargs: Passed to other setup functions.
         """
@@ -384,6 +387,8 @@ def setup_spacecraft_hub(
             self.task_name, self.scObject, ModelPriority=priority
         )
 
+        self.min_orbital_radius = min_orbital_radius
+
         self.setup_gravity_bodies()
         self.setup_disturbance_torque(**kwargs)
         self.setup_density_model()
@@ -502,9 +507,10 @@ def setup_simple_nav_object(self, priority: int = 1400, **kwargs) -> None:
     def altitude_valid(self) -> bool:
         """Check that satellite has not deorbited.
 
-        Checks if altitude is greater than 200km above Earth's surface.
+        Checks if altitude is greater than the configurable minimum orbital radius
+        (`min_orbital_radius`). The default value corresponds to 200km above Earth's surface.
         """
-        return np.linalg.norm(self.r_BN_N) > (orbitalMotion.REQ_EARTH + 200) * 1e3
+        return np.linalg.norm(self.r_BN_N) > self.min_orbital_radius
 
     @default_args(
         wheelSpeeds=lambda: np.random.uniform(-1500, 1500, 3),
diff --git a/tests/unittest/sim/test_dynamics.py b/tests/unittest/sim/test_dynamics.py
index 65a30ad4..a4d2c806 100644
--- a/tests/unittest/sim/test_dynamics.py
+++ b/tests/unittest/sim/test_dynamics.py
@@ -153,6 +153,7 @@ def test_wheel_properties(self):
     )
     def test_altitude_valid(self, vec, valid):
         dyn = BasicDynamicsModel(MagicMock(simulator=MagicMock()), 1.0)
+        dyn.min_orbital_radius = 1e6
         dyn.simulator.world = MagicMock()
         dyn.scObject = MagicMock()
         message = dyn.scObject.scStateOutMsg.read.return_value