Atmospheric re-entry is a crucial stage in many space missions, as it involves massive structural and thermal loads on the spacecraft. There are two types of atmospheric re-entries:
- Lifting: performed by maneuverable vehicles, where lift force can be controlled to follow a specific trajectory (Space Shuttle).
- Ballistic: reentry vehicles, Mercury capsules, etc.
The aim of this project was to reproduce the figures in reference [1]. This was joint work with Yi Qiang Ji Zhang and Iván Sermanoukian Molina.
A MATLAB script was programmed for this project. To compute the trajectory, it solves the flight mechanics equations using a Runge-Kutta 4 method.
The main file for the project is main.m (who would have thought it), while the other files are functions. Code sections:
- Constants: universal constants and Earth/Mars atmospheric data
- Previous calculations: compute properties for each atmospheric layer
- Ballistic reentry: solves ballistic reentries for different ballistic coefficients
$(\beta = W / (C_D A))$ - Mercury capsule reentry: solves the ballistic reentry of a Mercury capsule
- Lifting reentry: solves a lifting reentry
- Solution: plots the desired results
Upon execution, the script will prompt for planet number (1 - Earth, 2 - Mars). You can define your own planet in section 1 of the code. As for atmospheric data:
- Temperature is used to compute pressure and density.
- Temperature is assumed to behave linearly within an atmospheric layer.
- Elevation of atmospheric layers is defined in ```H_layer_Earth```.
- Temperature gradient of each atmospheric layer is defined in ```lambda_layer_Earth```.
- Heat capacity ratio (
$\gamma$ ) is defined in ```gamma_gas_Earth```.
[1] J.C. Adams Jr. Atmospheric Reentry, June 2003. 2011