this is a good start

satrs-book/src/SUMMARY.md

@@ -1,5 +1,6 @@
 # Summary
 
-- [The sat-rs book](./title-page.md)
 - [Introduction](./introduction.md)
+- [Design](./design.md)
+
 

satrs-book/src/design.md

@@ -0,0 +1,57 @@
+# Framework Design
+
+Satellites and space systems in general are complex systems with a wide range of requirements for
+both the hardware and the software.
+Consequently, the general design of the framework is centered around many light-weight components
+which try to impose as few restrictions as possible on how to solve certain problems.
+
+There are still a lot of common patterns and architectures across these systems where guidance
+of how to solve a problem and a common structure would still be extremely useful to avoid pitfalls
+which were already solved and to avoid boilerplate code. This framework tries to provide this
+structure and guidance the following way:
+
+1. Providing this book which explains the architecture and design patterns in respect to common
+   issues and requirements of space systems.
+2. Providing an example application. Space systems still commonly have large monolithic
+   primary On-Board Softwares, so the choice was made to provide one example software which
+   contains the various features provided by sat-rs.
+3. Providing a good test suite. This includes both unittests and integration tests. The integration
+   tests can also serve as smaller usage examples than the large `satrs-example` application.
+
+This framework has special support for standards used in the space industry. This especially
+includes standards provided by Consultative Committee for Space Data Systems (CCSDS) and European
+Cooperation for Space Standardization (ECSS). It does not enforce using any of those standards,
+but it is always recommended to use some sort of standard for interoperability.
+
+A lot of the modules and design considerations are based on the Flight Software Framework (FSFW).
+The FSFW has its own [documentation](https://documentation.irs.uni-stuttgart.de/fsfw/), which
+will be referred to when applicable. The FSFW was developed over a period of 10 years for the
+Flying Laptop Project by the University of Stuttgart with Airbus Defence and Space GmbH.
+It has flight heritage through the 2 mssions [FLP](https://www.irs.uni-stuttgart.de/en/research/satellitetechnology-and-instruments/smallsatelliteprogram/flying-laptop/)
+and [EIVE](https://www.irs.uni-stuttgart.de/en/research/satellitetechnology-and-instruments/smallsatelliteprogram/EIVE/).
+Therefore, a lot of the design concepts were ported more or less unchanged to the `sat-rs`
+framework.
+FLP is a medium-size small satellite with a higher budget and longer development time than EIVE,
+which allowed to build a highly reliable system while EIVE is a smaller 6U+ cubesat which had a
+shorter development cycle and was built using cheaper COTS components. This framework also tries
+to accumulate the knowledge of developing the OBSW and operating the satellite for both these
+different systems and provide a solution for a wider range of small satellite systems.
+
+`sat-rs` can be seen as a modern port of the FSFW which uses common principles of software
+engineering to provide a reliable and robust basis for space On-Board Software. The choice
+of using the Rust programming language was made for the following reasons:
+
+1. Rust has safety guarantees which are a perfect fit for space systems which generally have high
+   robustness and reliablity guarantees.
+2. Rust is suitable for embedded systems. It can also be run on smaller embedded systems like the
+   STM32 which have also become common in the space sector. All space systems are embedded systems,
+   which makes using large languages like Python challenging even for OBCs with more performance.
+3. Rust has support for linking C APIs through its excellent FFI support. This is especially
+   important because many vendor provided libaries are still C based.
+4. Modern tooling like a package managers and various development helper, which can further reduce
+   development cycles for space systems. `cargo` provides tools like auto-formatters and linters
+   which can immediately ensure a high software quality throughout each development cycle.
+5. A large ecosystem with excellent libraries which also leverages the excellent tooling provided
+   previously. Integrating these libraries is a lot easier compared to languages like C/C++ where
+   there is still no standardized way to use packages.
+

satrs-book/src/introduction.md

@@ -1,6 +1,16 @@
+The sat-rs book
+======
+
+This book is the primary information resource for the [sat-rs framework](https://egit.irs.uni-stuttgart.de/rust/sat-rs)
+in addition to the regular API documentation. It contains the following resources:
+
+1. Architecture informations and consideration which would exceeds the scope of the regular API.
+2. A Getting-Started workshop where a small On-Board Software is built from scratch using
+   sat-rs components.
+
 # Introduction
 
-This is the repository of the sat-rs framework. Its primary goal is to provide re-usable components
+The primary goal of the sat-rs framework is to provide re-usable components
 to write on-board software for remote systems like rovers or satellites. It is specifically written
 for the special requirements for these systems.
 

satrs-book/src/title-page.md

@@ -1,10 +0,0 @@
-The sat-rs book
-======
-
-This book is the primary information resource for the [sat-rs framework](https://egit.irs.uni-stuttgart.de/rust/sat-rs)
-in addition to the regular API documentation. It contains the following resources:
-
-1. Architecture informations and consideration which would exceeds the scope of the regular API.
-2. A Getting-Started workshop where a small On-Board Software is built from scratch using
-   sat-rs components.
-