Student-Projects/2025-Rocket-Satellite.md

 ---
 title: 2025 Rocket Satellite
 ---
+
 <details>
 <summary>Table Of Contents</summary>
 
@@ -56,23 +57,23 @@ Ideally this will be done in a group of 3 students
 
 **Dimensions and Weight**
 
-The fairing should keep its original proportions and diamater to still fit into the Ariane 6 Rocket. It should also stay below a certain weight limit where the flight of the rocket would still be stable.
+The fairing should keep its original proportions and diameter to still fit into the Ariane 6 Rocket. It should also stay below a certain weight limit where the flight of the rocket would still be stable.
 
 **Opening Mechanism for the Fairing**
 
-The fairing or cargo section should be able to open or detach itself from the rest of the assembly to be able to release the satelite.
+The fairing or cargo section should be able to open or detach itself from the rest of the assembly to be able to release the satellite.
 
-**Release Mechanism for the Satelite**
+**Release Mechanism for the Satellite**
 
-The satelite should be deployed around apogee by our electronics.
+The satellite should be deployed around apogee by our electronics.
 
 **Space for Electronics**
 
-Besides the satelite there should be enought space to hold all electronics, power delivery, cables and motors without getting tangled up with the payload during the flight or release.
+Besides the satellite there should be enough space to hold all electronics, power delivery, cables and motors without getting tangled up with the payload during the flight or release.
 
 **Recovery System**
 
-The satelite aswell as the fairing and cargo section should be recovered with the main rocket parachute or on its own with a seperate parachute.
+The satellite as well as the fairing and cargo section should be recovered with the main rocket parachute or on its own with a separate parachute.
 
 ### Concepts & Ideas
 
@@ -90,13 +91,13 @@ A motor would spin a 3D printed Spiral that would be connected with the two fair
 
 ![WhatsApp_Image_2025-05-14_at_13.22.04_-_Kopie](uploads/bd82d0d421c9ec3cabec2da3c8f6b00e/WhatsApp_Image_2025-05-14_at_13.22.04_-_Kopie.jpeg){width="208" height="360"}
 
-A spring would push the payload into pins on the top of the fairing locking it down, realeasing the spring would open the fairing and release the satelite.
+A spring would push the payload into pins on the top of the fairing locking it down, releasing the spring would open the fairing and release the satellite.
 
 **Cargo Bay Door**
 
 ![WhatsApp_Image_2025-05-14_at_13.22.04](uploads/37aed7af2be7638eff7fb01a866f1d1a/WhatsApp_Image_2025-05-14_at_13.22.04.jpeg)
 
-The fairing would stay closed and instead the cargo bay would partly open and release the satelite.
+The fairing would stay closed and instead the cargo bay would partly open and release the satellite.
 
 **Locking Cargo Section Bottom**
 
@@ -115,7 +116,7 @@ From left to right:
 1. Original Fairing Design.
 2. First try at a two fairing design.
 3. Changes to the aerodynamics of the fairing and how the two halves connect.
-4. Added storage inside the fairings for containing the satelite, first new cargo section design with removable bottom. Clamps for mounting the motors to the inside of the cargo section.
+4. Added storage inside the fairings for containing the satellite, first new cargo section design with removable bottom. Clamps for mounting the motors to the inside of the cargo section.
 5. Final design, added stronger hinges to reduce instability during opening and closing, improved removable bottom to fit easier. Added locking pins to the top of the fairings.
 
 ### Final Design
@@ -140,7 +141,7 @@ The top of the farings have little pins where the two halves meet to mechanicall
 
 ![Screenshot_2025-07-07_at_21-57-51_Fairing_Tests_Fairing_V2.3](uploads/1905fab2f49576b783ffdacf6820a99f/Screenshot_2025-07-07_at_21-57-51_Fairing_Tests_Fairing_V2.3.png){width="297" height="437"}
 
-The faring section would also contain the prototype satelite with its parachute.
+The faring section would also contain the prototype satellite with its parachute.
 
 **Cargo Section**
 
@@ -148,11 +149,11 @@ The faring section would also contain the prototype satelite with its parachute.
 
 The upper part of the cargo section would contain two linear servo motors which would open/close the fairings. They would be connected to the bottom of the fairings with little push rods. The electronics would be contained in the bottom part. With easy access due to the removable bottom, where the main rocket parachute would be attached.
 
-**Prototype Satelite**
+**Prototype Satellite**
 
 ![Screenshot_2025-07-07_at_22-00-13_Fairing_Tests_Fairing_V2.3](uploads/04d31a448c40cde8f1306252af10fff0/Screenshot_2025-07-07_at_22-00-13_Fairing_Tests_Fairing_V2.3.png){width="250" height="274"}
 
-Our placeholder satelite was a small ball that we could add weight to with coins and small attachements for a parachute.
+Our placeholder satellite was a small ball that we could add weight to with coins and small attachments for a parachute.
 
 ### Manufacturing and Assembly
 
@@ -167,22 +168,83 @@ The parts where all designed in CAD based of the original models and then 3D pri
 
 ### Testing
 
-For testing we used our software to trigger the motors to open and close the fairings. Aswell as a simulation software to check if the flight would be stable with our added weight. launch day ergebnis
+For testing we used our software to trigger the motors to open and close the fairings. As well as a simulation software to check if the flight would be stable with our added weight.
 
 ### Launch Day Results
 
-Even though one of the servos didnt work reliably and the locking pins for the fairing where not strong enought due to the packed up satalite parachute acting like a spring against the inside of the fairings. The satelite deployed successfully shortly after reaching apogee and accended on its parachute.
+Even though one of the servos didn't work reliably and the locking pins for the fairing where not strong enough due to the packed up satellite parachute acting like a spring against the inside of the fairings. The satellite deployed successfully shortly after reaching apogee and descended on its parachute.
 
 ### Conclusion
 
 **Evaluation of the Design**
 
-The design worked as inteded but still has issues with reliablity and can be quite difficult to assemble.
+The design worked as intended but still has issues with reliability and can be quite difficult to assemble.
 
 **Improvements for the Future**
 
-Use better and more reliable motors. Improve the opening angle and the locking pins of the fairings. A bigger storage for the satelite could be achieved by reducing the size of the cargo section which was mostly empty.
+Use better and more reliable motors. Improve the opening angle and the locking pins of the fairings. A bigger storage for the satellite could be achieved by reducing the size of the cargo section which was mostly empty.
 
 ## Electrical Design (@stlerohss)
 
-## Software Design (@stsuyooo)
+## Software Design (@stsuyooo)
\ No newline at end of file
+To keep it simple an illustration of the state machine will be used to explain the software. To see the full code visit the project [repository](https://code.fbi.h-da.de/hda10343/dla/-/tree/Satellite/Satellite?ref_type=heads).
+### State Machine
+
+![AltimeterStateMachine](uploads/eb8b58040fb917a6725628f2a4b91f9c/AltimeterStateMachine.png)
+
+**st_Initialization**
+
+In the setup phase all the connection to the sensors and motors are established.
+
+**st_Standby**
+
+Idle state after the setup or landing.
+
+**st_cargoOpen**
+
+To make it possible to insert the satellite after assembly, manual opening of the cargo, by actuating the button, has been ensured.
+
+**st_ready**
+
+Actuating the button again closes the cargo and the system is only one more button actuation away from being ready for launch.
+
+This state also prevents accidental activation of the release mechanism while preparing for launch.
+
+**st_Altimeter**
+
+In this state sensor data is processed to determine whether the apogee has been reached.
+When the apogee has been reached, meaning the rocket is falling, the release mechanism activates.
+The release mechanism also includes closing the cargo to prevent any potential damage to the fairings, when the cargo is left open.
+
+Some of the code from previous projects (e.g. sensor setup and sensor data readout) has been reused for this project.
+
+### Sensor data filter
+The sensor provides noisy measurements, so to ensure the reliability of the altitude readings, a simple 1D Kalman filter has been used.
+
+The math behind the Kalman Filter is as follows:
+
+**State variables:**
+ * X: current estimated altitude
+ * P: estimated error (uncertainty) in the estimate
+
+**Parameters:**
+ * Q: process noise (uncertainty in how altitude changes between steps)
+ * R: measurement noise (how noisy the sensor is)
+
+**1.Prediction step**
+
+Increase uncertainty because time has passed
+
+$P=P+Q$
+
+**2. Update step**
+
+Taking the new sensor reading _Z_ and adjust:
+
+$K=\frac{P}{P+R}$ (Kalman gain)
+
+$X=X+K*(Z-X)$ (update estimate)
+
+$P=(1-K)*P$ (update uncertainty)
+
+