From 523c5a6b86d9074a27526308a307fb4e8155ed1f Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Thu, 19 Jun 2025 12:01:00 -0400
Subject: [PATCH 01/16] ENH: added radius and porosity to parachute

---
 rocketpy/rocket/parachute.py  | 1 +
 rocketpy/simulation/flight.py | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/rocketpy/rocket/parachute.py b/rocketpy/rocket/parachute.py
index e27216e26..a3c13885e 100644
--- a/rocketpy/rocket/parachute.py
+++ b/rocketpy/rocket/parachute.py
@@ -191,6 +191,7 @@ def __init__(
         self.sampling_rate = sampling_rate
         self.lag = lag
         self.noise = noise
+        self.porosity = porosity
         self.noise_signal = [[-1e-6, np.random.normal(noise[0], noise[1])]]
         self.noisy_pressure_signal = []
         self.clean_pressure_signal = []
diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 30ea66466..cb3ae4b0b 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -2152,7 +2152,6 @@ def u_dot_parachute(self, t, u, post_processing=False):
 
         # Get the mass of the rocket
         mp = self.rocket.dry_mass
-
         # to = 1.2
         # eta = 1
         # Rdot = (6 * R * (1 - eta) / (1.2**6)) * (

From 9f28d6e933c5bbfee7b5a1c9773f95be328053bb Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Wed, 25 Jun 2025 21:12:21 -0400
Subject: [PATCH 02/16] ENH: fixing radius and height attribute in flight class

---
 rocketpy/simulation/flight.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index cb3ae4b0b..9f8d53270 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -769,10 +769,10 @@ def __simulate(self, verbose):
                             lambda self, parachute_cd_s=parachute.cd_s: setattr(
                                 self, "parachute_cd_s", parachute_cd_s
                             ),
-                            lambda self, parachute_radius=parachute.radius: setattr(
+                            lambda self, parachute_radius=parachute.parachute_radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
-                            lambda self, parachute_height=parachute.height: setattr(
+                            lambda self, parachute_height=parachute.parachute_height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From 7334fc4e58648e5b968c451ae5a5f61812d8926f Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Thu, 26 Jun 2025 12:31:44 -0400
Subject: [PATCH 03/16] STY: ruff formatting

---
 rocketpy/simulation/flight.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 9f8d53270..7fc71d647 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -769,10 +769,12 @@ def __simulate(self, verbose):
                             lambda self, parachute_cd_s=parachute.cd_s: setattr(
                                 self, "parachute_cd_s", parachute_cd_s
                             ),
-                            lambda self, parachute_radius=parachute.parachute_radius: setattr(
+                            lambda self,
+                            parachute_radius=parachute.parachute_radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
-                            lambda self, parachute_height=parachute.parachute_height: setattr(
+                            lambda self,
+                            parachute_height=parachute.parachute_height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From bfb3f37d7e26b922aef3e5d3cca92a490d8df89e Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Tue, 1 Jul 2025 11:07:29 -0400
Subject: [PATCH 04/16] ENH: added new parameters into add_parachute method in
 Rocket class

---
 rocketpy/rocket/parachute.py | 24 +++++++++++++++++++++++-
 rocketpy/rocket/rocket.py    | 13 +++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/rocketpy/rocket/parachute.py b/rocketpy/rocket/parachute.py
index a3c13885e..204b9973c 100644
--- a/rocketpy/rocket/parachute.py
+++ b/rocketpy/rocket/parachute.py
@@ -92,6 +92,7 @@ class Parachute:
         Function of noisy_pressure_signal.
     Parachute.clean_pressure_signal_function : Function
         Function of clean_pressure_signal.
+<<<<<<< HEAD
     Parachute.radius : float
         Length of the non-unique semi-axis (radius) of the inflated hemispheroid
         parachute in meters.
@@ -106,6 +107,15 @@ class Parachute:
     Parachute.added_mass_coefficient : float
         Coefficient used to calculate the added-mass due to dragged air. It is
         calculated from the porosity of the parachute.
+=======
+    Parachute.parachute_radius : float
+        Radius of the inflated parachute in meters.
+    Parachute.parachute_height : float
+        Height of the inflated parachute in meters.
+    Parachute.porosity : float
+        Porosity of the parachute material, which is a measure of how much air can
+        pass through the parachute material.
+>>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
     """
 
     def __init__(
@@ -171,6 +181,7 @@ def __init__(
             The values are used to add noise to the pressure signal which is
             passed to the trigger function. Default value is ``(0, 0, 0)``.
             Units are in Pa.
+<<<<<<< HEAD
         radius : float, optional
             Length of the non-unique semi-axis (radius) of the inflated hemispheroid
             parachute. Default value is 1.5.
@@ -184,6 +195,18 @@ def __init__(
             in [0, 1]. Affects only the added-mass scaling during descent; it does
             not change ``cd_s`` (drag). The default, 0.0432, yields an added-mass
             of 1.0 (“neutral” behavior).
+=======
+        parachute_radius : float, optional
+            Radius of the inflated parachute. Default value is 1.5.
+            Units are in meters.
+        parachute_height : float, optional
+            Height of the inflated parachute. Default value is the radius parachute.
+            Units are in meters.
+        porosity : float, optional
+            Porosity of the parachute material, which is a measure of how much air can
+            pass through the parachute material.
+            Default value is 0.0432 (for consistency with previous versions).
+>>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
         """
         self.name = name
         self.cd_s = cd_s
@@ -210,7 +233,6 @@ def __init__(
             - 0.25975 * self.porosity**2
             + 1.2626 * self.porosity**3
         )
-
         alpha, beta = self.noise_corr
         self.noise_function = lambda: alpha * self.noise_signal[-1][
             1
diff --git a/rocketpy/rocket/rocket.py b/rocketpy/rocket/rocket.py
index 63853a399..0c0bf3850 100644
--- a/rocketpy/rocket/rocket.py
+++ b/rocketpy/rocket/rocket.py
@@ -1536,6 +1536,7 @@ def add_parachute(
             The values are used to add noise to the pressure signal which is
             passed to the trigger function. Default value is (0, 0, 0). Units
             are in pascal.
+<<<<<<< HEAD
         radius : float, optional
             Length of the non-unique semi-axis (radius) of the inflated hemispheroid
             parachute. Default value is 1.5.
@@ -1549,6 +1550,18 @@ def add_parachute(
             in [0, 1]. Affects only the added-mass scaling during descent; it does
             not change ``cd_s`` (drag). The default, 0.0432, yields an added-mass
             of 1.0 (“neutral” behavior).
+=======
+        parachute_radius : float, optional
+            Radius of the inflated parachute. Default value is 1.5.
+            Units are in meters.
+        parachute_height : float, optional
+            Height of the inflated parachute. Default value is the radius parachute.
+            Units are in meters.
+        porosity : float, optional
+            Porosity of the parachute material, which is a measure of how much air can
+            pass through the parachute material.
+            Default value is 0.0432 (for consistency with previous versions).
+>>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
 
         Returns
         -------

From a16a48c67c443d236bda564a519050d560d5a85a Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Thu, 3 Jul 2025 10:35:18 -0400
Subject: [PATCH 05/16] DOC: added new parameters to the documentation

---
 README.md                         | 6 ++++++
 docs/user/first_simulation.rst    | 5 +++++
 docs/user/rocket/rocket_usage.rst | 5 +++++
 3 files changed, 16 insertions(+)

diff --git a/README.md b/README.md
index 8247ab1a3..0718153dd 100644
--- a/README.md
+++ b/README.md
@@ -262,6 +262,7 @@ main = calisto.add_parachute(
     sampling_rate=105,
     lag=1.5,
     noise=(0, 8.3, 0.5),
+<<<<<<< HEAD
     radius=1.5,
     height=1.5,
     porosity=0.0432,
@@ -274,8 +275,13 @@ drogue = calisto.add_parachute(
     sampling_rate=105,
     lag=1.5,
     noise=(0, 8.3, 0.5),
+<<<<<<< HEAD
     radius=1.5,
     height=1.5,
+=======
+    parachute_radius=1.5,
+    parachute_height=1.5,
+>>>>>>> 7defc38c (DOC: added new parameters to the documentation)
     porosity=0.0432,
 )
 ```
diff --git a/docs/user/first_simulation.rst b/docs/user/first_simulation.rst
index 1e341e9b1..8bcb097df 100644
--- a/docs/user/first_simulation.rst
+++ b/docs/user/first_simulation.rst
@@ -276,8 +276,13 @@ Finally, we can add any number of Parachutes to the ``Rocket`` object.
         sampling_rate=105,
         lag=1.5,
         noise=(0, 8.3, 0.5),
+<<<<<<< HEAD
         radius=1.5,
         height=1.5,
+=======
+        parachute_radius=1.5,
+        parachute_height=1.5,
+>>>>>>> 7defc38c (DOC: added new parameters to the documentation)
         porosity=0.0432,
     )
 
diff --git a/docs/user/rocket/rocket_usage.rst b/docs/user/rocket/rocket_usage.rst
index 3496da6fd..191d98808 100644
--- a/docs/user/rocket/rocket_usage.rst
+++ b/docs/user/rocket/rocket_usage.rst
@@ -314,8 +314,13 @@ apogee and another that will be deployed at 800 meters above ground level:
         sampling_rate=105,
         lag=1.5,
         noise=(0, 8.3, 0.5),
+<<<<<<< HEAD
         radius=1.5,
         height=1.5,
+=======
+        parachute_radius=1.5,
+        parachute_height=1.5,
+>>>>>>> 7defc38c (DOC: added new parameters to the documentation)
         porosity=0.0432,
     )
 

From 7404daae08dadfafd684ab807f56087669824812 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Tue, 15 Jul 2025 07:49:17 -0400
Subject: [PATCH 06/16] DOC: improved descriptions of the new parameters

---
 rocketpy/rocket/parachute.py | 23 -----------------------
 rocketpy/rocket/rocket.py    | 15 +--------------
 2 files changed, 1 insertion(+), 37 deletions(-)

diff --git a/rocketpy/rocket/parachute.py b/rocketpy/rocket/parachute.py
index 204b9973c..e80c721ad 100644
--- a/rocketpy/rocket/parachute.py
+++ b/rocketpy/rocket/parachute.py
@@ -92,7 +92,6 @@ class Parachute:
         Function of noisy_pressure_signal.
     Parachute.clean_pressure_signal_function : Function
         Function of clean_pressure_signal.
-<<<<<<< HEAD
     Parachute.radius : float
         Length of the non-unique semi-axis (radius) of the inflated hemispheroid
         parachute in meters.
@@ -107,15 +106,6 @@ class Parachute:
     Parachute.added_mass_coefficient : float
         Coefficient used to calculate the added-mass due to dragged air. It is
         calculated from the porosity of the parachute.
-=======
-    Parachute.parachute_radius : float
-        Radius of the inflated parachute in meters.
-    Parachute.parachute_height : float
-        Height of the inflated parachute in meters.
-    Parachute.porosity : float
-        Porosity of the parachute material, which is a measure of how much air can
-        pass through the parachute material.
->>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
     """
 
     def __init__(
@@ -181,7 +171,6 @@ def __init__(
             The values are used to add noise to the pressure signal which is
             passed to the trigger function. Default value is ``(0, 0, 0)``.
             Units are in Pa.
-<<<<<<< HEAD
         radius : float, optional
             Length of the non-unique semi-axis (radius) of the inflated hemispheroid
             parachute. Default value is 1.5.
@@ -195,18 +184,6 @@ def __init__(
             in [0, 1]. Affects only the added-mass scaling during descent; it does
             not change ``cd_s`` (drag). The default, 0.0432, yields an added-mass
             of 1.0 (“neutral” behavior).
-=======
-        parachute_radius : float, optional
-            Radius of the inflated parachute. Default value is 1.5.
-            Units are in meters.
-        parachute_height : float, optional
-            Height of the inflated parachute. Default value is the radius parachute.
-            Units are in meters.
-        porosity : float, optional
-            Porosity of the parachute material, which is a measure of how much air can
-            pass through the parachute material.
-            Default value is 0.0432 (for consistency with previous versions).
->>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
         """
         self.name = name
         self.cd_s = cd_s
diff --git a/rocketpy/rocket/rocket.py b/rocketpy/rocket/rocket.py
index 0c0bf3850..4c59ca8b2 100644
--- a/rocketpy/rocket/rocket.py
+++ b/rocketpy/rocket/rocket.py
@@ -1536,7 +1536,6 @@ def add_parachute(
             The values are used to add noise to the pressure signal which is
             passed to the trigger function. Default value is (0, 0, 0). Units
             are in pascal.
-<<<<<<< HEAD
         radius : float, optional
             Length of the non-unique semi-axis (radius) of the inflated hemispheroid
             parachute. Default value is 1.5.
@@ -1550,19 +1549,7 @@ def add_parachute(
             in [0, 1]. Affects only the added-mass scaling during descent; it does
             not change ``cd_s`` (drag). The default, 0.0432, yields an added-mass
             of 1.0 (“neutral” behavior).
-=======
-        parachute_radius : float, optional
-            Radius of the inflated parachute. Default value is 1.5.
-            Units are in meters.
-        parachute_height : float, optional
-            Height of the inflated parachute. Default value is the radius parachute.
-            Units are in meters.
-        porosity : float, optional
-            Porosity of the parachute material, which is a measure of how much air can
-            pass through the parachute material.
-            Default value is 0.0432 (for consistency with previous versions).
->>>>>>> 78ef92e7 (ENH: added new parameters into add_parachute method in Rocket class)
-
+            
         Returns
         -------
         parachute : Parachute

From 2f15b09edb15c254978293cfc5de5337deb625a3 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Tue, 12 Aug 2025 09:48:46 -0400
Subject: [PATCH 07/16] ENH: implementing previous comments

---
 rocketpy/simulation/flight.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 7fc71d647..306a5492e 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -2164,6 +2164,7 @@ def u_dot_parachute(self, t, u, post_processing=False):
         # tf = 8 * nominal diameter / velocity at line stretch
 
         # Calculate added mass
+<<<<<<< HEAD
         ma = (
             self.parachute_added_mass_coefficient
             * rho
@@ -2172,6 +2173,9 @@ def u_dot_parachute(self, t, u, post_processing=False):
             * self.parachute_radius**2
             * self.parachute_height
         )
+=======
+        ma = ka * rho * (4 / 3) * np.pi * self.parachute_radius**2 * self.parachute_height
+>>>>>>> 159cce8e (ENH: implementing previous comments)
 
         # Calculate freestream speed
         freestream_x = vx - wind_velocity_x

From 81667b5dcc26a7041147d2e08f08dde72dd72745 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Tue, 12 Aug 2025 10:04:24 -0400
Subject: [PATCH 08/16] ENH: fixing formatting and adding docs

---
 rocketpy/simulation/flight.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 306a5492e..7fc71d647 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -2164,7 +2164,6 @@ def u_dot_parachute(self, t, u, post_processing=False):
         # tf = 8 * nominal diameter / velocity at line stretch
 
         # Calculate added mass
-<<<<<<< HEAD
         ma = (
             self.parachute_added_mass_coefficient
             * rho
@@ -2173,9 +2172,6 @@ def u_dot_parachute(self, t, u, post_processing=False):
             * self.parachute_radius**2
             * self.parachute_height
         )
-=======
-        ma = ka * rho * (4 / 3) * np.pi * self.parachute_radius**2 * self.parachute_height
->>>>>>> 159cce8e (ENH: implementing previous comments)
 
         # Calculate freestream speed
         freestream_x = vx - wind_velocity_x

From 4dac7489a997d891114c491409b48161ee3f3ebd Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Fri, 31 Oct 2025 22:13:35 -0400
Subject: [PATCH 09/16] ENH: Sketch implementation of parachute inflation

---
 rocketpy/simulation/flight.py | 53 +++++++++++++++++++++++++++++------
 1 file changed, 45 insertions(+), 8 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 7fc71d647..2d859ba68 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -2164,14 +2164,14 @@ def u_dot_parachute(self, t, u, post_processing=False):
         # tf = 8 * nominal diameter / velocity at line stretch
 
         # Calculate added mass
-        ma = (
-            self.parachute_added_mass_coefficient
-            * rho
-            * (2 / 3)
-            * np.pi
-            * self.parachute_radius**2
-            * self.parachute_height
-        )
+        # ma = (
+        #     self.parachute_added_mass_coefficient
+        #     * rho
+        #     * (2 / 3)
+        #     * np.pi
+        #     * self.parachute_radius**2
+        #     * self.parachute_height
+        # )
 
         # Calculate freestream speed
         freestream_x = vx - wind_velocity_x
@@ -2179,6 +2179,43 @@ def u_dot_parachute(self, t, u, post_processing=False):
         freestream_z = vz
         free_stream_speed = (freestream_x**2 + freestream_y**2 + freestream_z**2) ** 0.5
 
+        # Initialize parachute state parameters if necessary (wouldn't work for more than one parachute)
+        self.parachute_inflated_radius = getattr(
+            self, "parachute_inflated_radius", self.rocket.radius
+        )
+        self.volume = getattr(self, "volume", 0)
+
+        radius = self.parachute_radius
+        height = self.parachute_height
+        inflated_radius = self.parachute_inflated_radius
+        inflated_height = inflated_radius * height / radius
+
+        # Calculate the surface area of the parachute
+        if radius > height:
+            e = math.sqrt(1 - (inflated_height**2) / (inflated_radius**2))
+            surface_area = math.pi * inflated_radius**2 * (1 + (1 - e ^ 2) / e * math.atanh(e))
+        else:
+            e = math.sqrt(1 - (inflated_radius**2) / (inflated_height**2))
+            surface_area = (
+                math.pi * inflated_radius**2 * (1 + inflated_height / (e * inflated_radius) * math.asin(e))
+            )
+
+        volume_flow = (
+            rho
+            * freestream_z # considering parachute as vertical
+            * (
+                (math.pi * inflated_radius**2)
+                - (self.parachute_porosity * surface_area)
+            )
+        )
+        self.volume += volume_flow  # * time_step
+        self.inflated_radius = ((3 * self.volume * radius) / (4 * math.pi * height)) ** (
+            1 / 3
+        )
+
+        # Dragged air mass
+        ma = self.volume * rho
+
         # Determine drag force
         pseudo_drag = -0.5 * rho * self.parachute_cd_s * free_stream_speed
         # pseudo_drag = pseudo_drag - ka * rho * 4 * np.pi * (R**2) * Rdot

From f1fa769e1dd88e919765a5bc21b92fdc2b4e564a Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Wed, 25 Jun 2025 20:57:52 -0400
Subject: [PATCH 10/16] ENH: added parachute radius

---
 rocketpy/simulation/flight.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 2d859ba68..ba39640c6 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -773,8 +773,7 @@ def __simulate(self, verbose):
                             parachute_radius=parachute.parachute_radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
-                            lambda self,
-                            parachute_height=parachute.parachute_height: setattr(
+                            lambda self, parachute_height=parachute.height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From 7aef262a8e53bd8e47b5a8d0dce9ad6bf14be5df Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Wed, 25 Jun 2025 21:12:21 -0400
Subject: [PATCH 11/16] ENH: fixing radius and height attribute in flight class

---
 rocketpy/simulation/flight.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index ba39640c6..405172cb4 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -773,7 +773,7 @@ def __simulate(self, verbose):
                             parachute_radius=parachute.parachute_radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
-                            lambda self, parachute_height=parachute.height: setattr(
+                            lambda self, parachute_height=parachute.parachute_height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From c7dc21dfc677a4ad73a6db55193711d1fcde76e0 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Thu, 26 Jun 2025 12:31:44 -0400
Subject: [PATCH 12/16] STY: ruff formatting

---
 rocketpy/simulation/flight.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 405172cb4..2d859ba68 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -773,7 +773,8 @@ def __simulate(self, verbose):
                             parachute_radius=parachute.parachute_radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
-                            lambda self, parachute_height=parachute.parachute_height: setattr(
+                            lambda self,
+                            parachute_height=parachute.parachute_height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From 85fb3b8eb2cd5858121ebfe762934d1b6615ed8b Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Tue, 1 Jul 2025 11:07:29 -0400
Subject: [PATCH 13/16] ENH: added new parameters into add_parachute method in
 Rocket class

---
 rocketpy/rocket/parachute.py | 1 -
 rocketpy/rocket/rocket.py    | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/rocketpy/rocket/parachute.py b/rocketpy/rocket/parachute.py
index e80c721ad..dbb98b493 100644
--- a/rocketpy/rocket/parachute.py
+++ b/rocketpy/rocket/parachute.py
@@ -191,7 +191,6 @@ def __init__(
         self.sampling_rate = sampling_rate
         self.lag = lag
         self.noise = noise
-        self.porosity = porosity
         self.noise_signal = [[-1e-6, np.random.normal(noise[0], noise[1])]]
         self.noisy_pressure_signal = []
         self.clean_pressure_signal = []
diff --git a/rocketpy/rocket/rocket.py b/rocketpy/rocket/rocket.py
index 4c59ca8b2..63853a399 100644
--- a/rocketpy/rocket/rocket.py
+++ b/rocketpy/rocket/rocket.py
@@ -1549,7 +1549,7 @@ def add_parachute(
             in [0, 1]. Affects only the added-mass scaling during descent; it does
             not change ``cd_s`` (drag). The default, 0.0432, yields an added-mass
             of 1.0 (“neutral” behavior).
-            
+
         Returns
         -------
         parachute : Parachute

From 301e08ff504be28e7ff27dda3758885b71df38f7 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Thu, 3 Jul 2025 10:35:18 -0400
Subject: [PATCH 14/16] DOC: added new parameters to the documentation

---
 README.md                         | 6 ------
 docs/user/first_simulation.rst    | 5 -----
 docs/user/rocket/rocket_usage.rst | 5 -----
 3 files changed, 16 deletions(-)

diff --git a/README.md b/README.md
index 0718153dd..8247ab1a3 100644
--- a/README.md
+++ b/README.md
@@ -262,7 +262,6 @@ main = calisto.add_parachute(
     sampling_rate=105,
     lag=1.5,
     noise=(0, 8.3, 0.5),
-<<<<<<< HEAD
     radius=1.5,
     height=1.5,
     porosity=0.0432,
@@ -275,13 +274,8 @@ drogue = calisto.add_parachute(
     sampling_rate=105,
     lag=1.5,
     noise=(0, 8.3, 0.5),
-<<<<<<< HEAD
     radius=1.5,
     height=1.5,
-=======
-    parachute_radius=1.5,
-    parachute_height=1.5,
->>>>>>> 7defc38c (DOC: added new parameters to the documentation)
     porosity=0.0432,
 )
 ```
diff --git a/docs/user/first_simulation.rst b/docs/user/first_simulation.rst
index 8bcb097df..1e341e9b1 100644
--- a/docs/user/first_simulation.rst
+++ b/docs/user/first_simulation.rst
@@ -276,13 +276,8 @@ Finally, we can add any number of Parachutes to the ``Rocket`` object.
         sampling_rate=105,
         lag=1.5,
         noise=(0, 8.3, 0.5),
-<<<<<<< HEAD
         radius=1.5,
         height=1.5,
-=======
-        parachute_radius=1.5,
-        parachute_height=1.5,
->>>>>>> 7defc38c (DOC: added new parameters to the documentation)
         porosity=0.0432,
     )
 
diff --git a/docs/user/rocket/rocket_usage.rst b/docs/user/rocket/rocket_usage.rst
index 191d98808..3496da6fd 100644
--- a/docs/user/rocket/rocket_usage.rst
+++ b/docs/user/rocket/rocket_usage.rst
@@ -314,13 +314,8 @@ apogee and another that will be deployed at 800 meters above ground level:
         sampling_rate=105,
         lag=1.5,
         noise=(0, 8.3, 0.5),
-<<<<<<< HEAD
         radius=1.5,
         height=1.5,
-=======
-        parachute_radius=1.5,
-        parachute_height=1.5,
->>>>>>> 7defc38c (DOC: added new parameters to the documentation)
         porosity=0.0432,
     )
 

From b18b9bfd0b1d21b186efe790a1aad1fa7eb5772b Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Mon, 10 Nov 2025 15:53:52 -0500
Subject: [PATCH 15/16] MNT: manually fixing remaining errors from rebase

---
 rocketpy/simulation/flight.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 2d859ba68..5cc523307 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -770,11 +770,11 @@ def __simulate(self, verbose):
                                 self, "parachute_cd_s", parachute_cd_s
                             ),
                             lambda self,
-                            parachute_radius=parachute.parachute_radius: setattr(
+                            parachute_radius=parachute.radius: setattr(
                                 self, "parachute_radius", parachute_radius
                             ),
                             lambda self,
-                            parachute_height=parachute.parachute_height: setattr(
+                            parachute_height=parachute.height: setattr(
                                 self, "parachute_height", parachute_height
                             ),
                             lambda self, parachute_porosity=parachute.porosity: setattr(

From b861b2de50c7df8d8d4ee7d98cec994048af7979 Mon Sep 17 00:00:00 2001
From: ArthurJWH <arthurjwhwang@gmail.com>
Date: Mon, 10 Nov 2025 15:56:34 -0500
Subject: [PATCH 16/16] MNT: fixing typo for exponentiation operator

---
 rocketpy/simulation/flight.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rocketpy/simulation/flight.py b/rocketpy/simulation/flight.py
index 5cc523307..0d4cd0a4f 100644
--- a/rocketpy/simulation/flight.py
+++ b/rocketpy/simulation/flight.py
@@ -2193,7 +2193,7 @@ def u_dot_parachute(self, t, u, post_processing=False):
         # Calculate the surface area of the parachute
         if radius > height:
             e = math.sqrt(1 - (inflated_height**2) / (inflated_radius**2))
-            surface_area = math.pi * inflated_radius**2 * (1 + (1 - e ^ 2) / e * math.atanh(e))
+            surface_area = math.pi * inflated_radius**2 * (1 + (1 - e**2) / e * math.atanh(e))
         else:
             e = math.sqrt(1 - (inflated_radius**2) / (inflated_height**2))
             surface_area = (