EMC Solar Sailors is a project from Exeter Mathematics School in which we are designing a spacecraft to harness the power of photons to get to Mars. This repo contains the code for our simulations and calculations.
See the latest simulation demo on Streamable: https://streamable.com/27g921. See the latest Blender render on Streamable: https://streamable.com/kq8n9h.
We've completed the first part of the project: getting a 1000kg payload to Mars. The parameters we used were a sail size of 750x750m, a launch trajectory of 135.071 degrees, a payload mass of 1000kg, the sail material was WES-Technik 2um aluminised mylar weighing 2.6g/m^2, a simulation length of 500 days, and all other parameters were default. Watch our final simulation here, or watch our stylised render here.
Run python main.py <launchDate> for a quick simulation without changing any parameters. Launch date is required and should be provided in the format dd/mm/yyyy. The optional parameters are as follows:
--mass(float): mass of the payload in kg, defaults to 1000--materialMass(float): mass of the sail material in g/m^2, defaults to 2.6 (mass of WES-Technik 2um aluminised mylar)--sailSize(float): side length of the sail in metres, defaults to 10--calculationsPerDay(int): number of calculations to simulate per day, defaults to 24. The more calculations, the higher the accuracy. Don't go below 24.--simulationLength(int): number of days to simulate for, defaults to 365.--accountForPlanets(switch/bool): whether to account for gravitational fields other than the sun's, False if not specified. This greatly increases the simulation time but may increase accuracy by about 0.015%.--lossless(switch/bool): whether to use lossless compression, False if not specified. Lossless compression (png rather than jpeg) takes twice as long to render but may improve image quality.--exportAsJSON(switch/bool): whether to export the simulation as JSON instead of a video, False if not specified. This is useful if you want to use Blender for rendering (see the "Using Blender for rendering" section) or to do more processing on the data afterwards.--returnDistance(switch/bool): whether to ignore rendering altogether and just return the closest distance, False if not specified. This is useful for finding angles.
This is what I've been using to test the latest commit with a calculation every second for a year.
python main.py 17/12/2020 --sailSize 500 --calculationsPerDay 1440A Blender import script is included with this repo to make it easy to use Blender to improve the graphics of your simulation render. Here's how you'd go about generating a simulation and rendering it in Blender:
- Generate your simulation the normal way, but make sure to pass the
--exportAsJSONparameter. For example, you could runpython main.py 13/09/2020 --exportAsJSONto use default parameters. - Open up Blender and go to the Scripting tab.
- Copy and paste the contents of the Blender import script into the code area.
- Change the
filepathvariable to point to your simulated JSON file. Don't forget to use double backslashes between directories. - Press the triangular run button in the top right of the code area and your simulation will be imported into Blender for you to customise!
- 11/09/2020: implemented gravity so the sail orbits the Sun with the Earth
- 25/09/2020: implemented first photon force so the sail is pushed by photons but the photons do not bounce off so the direction and magnitude are both inaccurate
- 06/10/2020: implemented photon rebounding, simulation code is nearing completion
- 07/10/2020: fixed major bug with photon rebounding and added more information in the top left
- 07/10/2020 Part 2: fixed acceleration bug so it's pretty much done
- 13/11/2020: completed first part of project
- Frankie Lambert
- Ella Ireland-Carson
- Ollie Temple (who also worked on
photons.py)