• Simulate spacecraft's attitude and orbit behavior in LEO and other orbits.
• Emulate spacecraft's components behavior not only sensors and actuators but also OBCs, power components, communications, and others.
• Emulate embedded software inside OBCs by connecting with C2A or others.
• Connect with Ground Station software.
• Output log files in CSV format.
• Connect with real OBCs for HILS tests.

• S2E CORE includes most of the functions for S2E.
• S2E user repositories include only files and source codes to define the simulation scenario.

Repository settings

• Branch structure

  - main        # The latest operation guaranteed codes for general users
  - develop     # The latest buildable codes for S2E primary developers
  - feature/*   # Developing codes
  - hotfix/*    # Bug Fix codes
  

• We recommend that the general users use the main branch or suitable released version because we sometimes update the develop branch without backward compatibility, and users need to modify their user side codes and settings.
• Push to main and develop is prohibited. All developers have to develop with feature/* or hotfix/* branch and make a pull request.
• Maintainers confirm the request and merge it to the develop or main branch.
• Reference document for the development style

Flow of development

1. Make a feature/* branch from the develop branch.
   • To fix the small bugs in the latest release codes, please make hotfix/* branch from the main branch
2. Edit, commit, and push in the branch.
   • Please check the coding convention and the code format in next section.
3. Create a new pull request to the develop branch.
   • The target branch becomes the main branch for the hotfix/* branchs.
4. A maintainer reviews the pull request. If some problems are found, the maintainer proposes modifications.
5. According to the maintainer's proposal, the developer modifies the codes and goes back to 3.
6. The maintainer merges the feature/* branch to the develop branch.
7. The code owners decide to merge the develop branch to the main branch and release a new version.

Binary files

• Binary file commit is prohibited.
• Please write the link to such files, or make a script file to get the files.
• Exception
  • Images for markdown document files are allowable when the file size is smaller than 200K Bytes.

Code format

• We use clang-format for format source code.
• We recommend install clang-format and format code before commit. It also will be checked on CI.
• Some modern editor has plugin/extension for code format. It will be very useful.
  • VSCode: C/C++
  • Vim: vim-clang-format

• Basic version format is <major>.<minor>.<patch>(like 4.0.0)
• Public API is declared in the code itself(currently, there is no definitive list)

• These versions are aliased with tags in the corresponding semver style(v2.0 -> v2.0.0)

• An example of S2E user side repository for Formation Flying study.