Spacecraft Dynamics And Missions Simulator
The Spacecraft Simulator application has the objective to implement the algorithms used in Orbital Mechanics and Entry Mechanics, integrating them inside a GUI application to simplify the analysis.
I decided to adopt the Python language to develop all the algorithms due to the high variety of libraries for scientific applications.
For the Graphical User Interface (GUI) I decided to rely on the QML language (part of the Qt environment) due to its flexibility and the nice and modern fill it can reach.
The application is developed in Python 3.11.2 and uses the following main libraries:
numpy 1.24.2for linear algebra and matrix manipulationmatplotlib 3.7.1for data visualizationscipy 1.10.1for numerical intergrationPySide6 6.7.0for the Grafical User Interface
The front-end is developed in Qt 6.7.0 using the QML language.
The project is structured in the following folders.
images: README imagesimg: icons and images used in the GUIlib: list of external librarieslib\matplotlib_backend_qtquick: library for integrating matplotlib in QMLlib\pyextrema: library implementing Matlab extrema function
src: back-end of the applicationtools: algorithmstools\texture: list of images for different astronomical objects
ui: front-end of the applicationui\components: list of components used in the GUIui\dialogs: list of dialogsui\pages: list of pagesmain.qml: root file of the QtQuick / QML projectqml.qrc: resource file for the QtQuick / QML projectqtquickcontrols2.conf: configuration file for the QtQuick / QML project
generate.bat: batch file used to compile the file qml.qrc in Pythonmain.py: root file of the Python project
Orbital Mechanics for Engineering Students
AuthorsHoward D. CurtisISBN9780080977485SeriesAerospace EngineeringYear2013PublisherElsevier ScienceURLhttps://www.google.it/books/edition/Orbital_Mechanics_for_Engineering_Studen/2U9Z8k0TlTYC?hl=it&gbpv=0
Manned Spacecraft: Design Principles
AuthorsPasquale M. SforzaISBN9780128044254SeriesAerospace EngineeringYear2016PublisherButterworth-HeinenmannURLhttps://www.google.it/books/edition/Manned_Spacecraft_Design_Principles/ntWcBAAAQBAJ?hl=it&gbpv=0
matplotlib_backend_qtquick
pyextrema
qbstyles
mplcyberpunk
Under the menu item Missions \ Spacecraft Properties it is possible to configure the Spacecraft Properties.
In the Propulsion section you can set:
- Initial Mass
- Specific Impulse
- Thrust
In the Aerodynamics section you can set:
- Lift Coefficient
- Drag Coefficient
- Reference Surface
- Radiation Pressure Coefficient (1 => absorbing surface, 2 => reflective surface)
- Absorbing Surface
In the Atmospheric Entry section you can set:
- Capsule (Nose Radius - Mass - Drag / Lift Coefficients - Reference Surface)
- Parachute (Drag Coefficient - Reference Surface)
Under the menu item Missions \ Current Mission it is possible to select the mission to analyze:
-
Orbit Transfer to simulate the cost in terms of
$\Delta v$ ,$\Delta t$ , and$\Delta m$ of the transfer between a departure and an arrival orbit. - Orbit Propagation to simulate the propagation of an orbit around Earth due to perturbations.
- Interplanetary Transfer to simulate the transfer between two planets of the Solar System.
- Atmospheric Entry to simulate the re-entry of a capsule with the addition of a parachute if required.
All these missions will be discussed in detail in the following sections.
An orbit transfer consists of a set of maneuvers to move a spacecraft from a departure orbit towards an arrival orbit. The user can decide the two orbits and the list of maneuver to simulate an orbit transfer.
Under the menu item Missions \ Orbit Transfer \ Departure Orbit it is possible to configure the Departure Orbit. The same discussion is valid for the Arrival Orbit. The orbit can be configured using one of the following representations:
- Cartesian based on the position vector and the velocity vector
- Keplerian based on the orbital elements
- Semi-major axis
- Eccentricity
- Inclination
- Right Ascension of the Ascending Node
- Anomaly of the Perigee
- True Anomaly
- Modified Keplerian based on the following elements
- Periapsis Radius
- Apoapsis Radius
- Inclination
- Right Ascension of the Ascending Node
- Anomaly of the Perigee
- True Anomaly
The user can select the planet that will be considered as the central body. In addition, a preview of the Orbit and the Ground Track can be visioned by the available buttons.
Under the menu item Missions \ Orbit Transfer \ Maneuvers it is possible to configure the maneuvers for the transfer between the departure and the arrival orbits, among the following ones:
- Hohmann Transfer
- Bi-Elliptic Hohmann Transfer
- Plane Change Maneuver
- Apse Line Rotation From Eta
After the transfer has been evaluated, the values of Save button to update the parameters.
By clicking on the Run button, the transfer is simulated and becomes visible in the chart.
Under the menu item Missions \ Orbit Propagation \ Orbital Perturbations it is possible to analyze the effects of the following perturbations on an orbit around Earth in a range of dates:
- Drag
- Gravitational
- Solar Radiation Pressure
- Third Body: the user shall select the third body between Moon and Sun
for a given set of initial orbital elements. By clicking on the Save button the parameters are updated.
To simulate the orbit propagation click on the Run button. The evolution of the orbital elements with respect to the initial values can be analyzed in the main window.
One of the most interesting aspect of space is space exploration. In this section I explain how the user can simulate an interplanetary transfer.
Under the menu item Missions \ Interplanetary \ Interplanetary Transfer it is possible to analyze/design the interplanetary transfer bewteen two planets of the Solar System, given a Launch Window and an Arrival Window. Once selected the parameters, by clicking on the Generate button the Pork Chop Plot is generated, and can be seen by clicking on the Show button. Use the Stop button to finish the generation before it ends.
After the analysis of the Pork Chop Plot, the actual transfer can be simulated, by choosing the effective departure and arrival dates, and the departure and arrival orbits around the planets.
The Atmospheric Entry problem studies what happens when an object (e.g. capsule carrying extraterrestrial meterial) re-enters on Earth.
Under the menu item Missions \ Atmospheric Entry \ Entry Conditions it is possible to set up the parameters needed to simulate a capsule re-entry: some of the data are also present in the Spacecraft Properties dialog.
- Entry Velocity
- Entry Flight Path Angle
- Entry Altitude
- Final Integration Time
- Use Parachute to simulate the parachute deployment
Under the results section the user can analyze the Impact Velocity at ground.
Click the Save button to update the parameters.
After you have decided the Entry Conditions, by clicking on the Run button, the simulation is executed and the results shown on the charts below. Each chart represents a peculiar parameter of the analysis:
- Velocity vs Time
- Acceleration g's vs Time
- Altitude vs Downrange Distance
- Fight Path Angle vs Time
- Stagnation Point Convective Heat Flux vs Time
- Altitude vs Velocity
