\section{Design}
\label{sec:design}
The following schematic design process is applied to \acs{ETPH}'s space related projects.

\begin{enumerate}
    \item Mission requirements review.
    \item Identifying critical design drivers. (In most cases the detectors.)
    \item Whiteboard Brainstorming: Detector arrangement (the telescope).
    \item Initial \acs{GEANT4} modeling and iteration.
    \item Intermediate telescope model freeze. \newline $\rightarrow$ Important to synchronize parallel activities and come to a mutual consensus between the different technical fields. \newline $\rightarrow$ Lab breadboarding activities start here.
    \item Electronics infrastructure\ area allocation (channel count/ board space).
    \item Implement structural/ thermal requirements on a conceptual level.
    \item Conceptual functional elements' arrangement (the initial chassis design concept). Activities supported by preliminary CAD studies (to-scale 'lego-bricks').
    \begin{enumerate}
        \item Refining accommodation constraints, e.g. max. lengths of signal lines, shielding, viewing direction, symmetries, ...
        \item Refine structural considerations, applicable I/F requirements.
    \end{enumerate}
    \item Setup of initial full-featured CAD model with to-scale functional elements.
    \item Iterate \acs{GEANT4} telescope simulation.
    \item Detailed conceptual telescope setup freeze. \newline $\rightarrow$ At this point all technical details of the telescope are finalized.
    \item Refine handling and composability (assembly concept) considerations followed by CAD implementation.
    \begin{enumerate}
        \item PreAmp/ Shaper accommodation.
        \item Detailed telescope design.
        \item PCB accommodation and wiring concept.
    \end{enumerate}
    \item Inital \acs{SMM} and \acs{TMM} runs.
    \item Implementing findings from breadboarding activities, simulation runs, detailing CAD modling.
    \item Detailed instrument design.    
\end{enumerate}