## 4 Propulsion System Design and Selection  
### Propulsion System Selection  
The selection of the propulsion system technology is largely dependent upon the mission requirements of the propulsion system [7]. The RAVAN mission payload requires the CubeSat to orbit at a 600 km orbit. This alone could be performed by releasing the CubeSat at a 600 km orbit and \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Component** & **Sub-Category** & **Specification** & **Suggested Component** & **Wish/Demand** \\ \hline \multirow{8}{*}{Structure} & \multirow{2}{*}{Dimensions} & The structure must conform to the & \(100\times 100\times 340\) mm & D \\  & & CubeSat Specification & & \\ \cline{2-5}  & \multirow{2}{*}{Mass} & The mass should aim to be as low as & \\  & & possible to ensure the CubeSat does & 0.5 kg & W \\  & & not exceed 4 kg & & \\ \cline{2-5}  & \multirow{2}{*}{Construction} & Part must easily assemble/integrate & & W \\ \cline{2-5}  & & with the design & & \\ \cline{2-5}  & \multirow{2}{*}{Materials} & Suitable for expected & & \\  & & stresses/temperatures and meet & 6061-T6/7071 & & \\  & & CubeSat regulations & & & \\ \hline \multirow{4}{*}{Thermal System} & \multirow{2}{*}{Management} & A thermal management system must be integrated to prevent component & Multi-Layer Insulation & \\  & & failure and ensure a safe operating & (MLI), Thermal Coatings, & \\  & & temperature range & & Passive systems over & \\ \hline \multirow{4}{*}{Mechanical} & \multirow{2}{*}{Altitude Control} & The CubeSat must be able to maintain a 600 km altitude, and perform orbital maneuvers & ISIS Magnetorquer & \\  & & maneuvers & & Board/Rod, Propulsion & \\  & & The CubeSat must have connectors & & \\  & & for installation and support on Earth & & \\  & & and P-POD & & \\ \cline{2-5}  & \multirow{2}{*}{Internal Layout} & Ensure all required components fit, & & \\  & & and maximize payload space & & \\ \cline{2-5}  & \multirow{2}{*}{Sidewalls} & Connect/Support external and & & \\  & & internal components & & \\ \hline \multirow{4}{*}{Payload} & \multirow{2}{*}{Class} & The payload’s dimensions must not & & W \\  & & be greater than 1U & & \\ \cline{2-5}  & \multirow{2}{*}{Type} & Fully developed and useable Carbon & & \\  & & Imbalance System & & \\ \hline \multirow{4}{*}{Antenna} & \multirow{2}{*}{Communications} & Design must include an antenna for & Deployable “thermal & \\  & & data transfer with ground station and & knife” system operating & D \\  & & other CubeSats & in UHF/VHF range & \\ \hline \multirow{4}{*}{Power Supply} & \multirow{2}{*}{Power Storage} & Electrical system must be able to store & & \\  & & power to power sub-systems, & & \\ \cline{2-5}  & & particularly in the eclipse phase & & \\ \cline{2-5}  & \multirow{2}{*}{Power Generation} & CubeSat must generate power to & & Spectrolab XT] Solar Cell & \\  & & maintain sub-systems and charge & (GaAs) & \\ \cline{2-5}  & \multirow{2}{*}{Power Management} & System must incorporate a PMAD to & & \\ \cline{2-5}  & & transform voltage and efficiently & & \\ \cline{2-5}  & & manage the electrical power supply & & \\ \cline{2-5}  & \multirow{2}{*}{Power Consumption} & Components on board the satellite & & \\ \cline{2-5}  & & must draw the minimum amount of & & W \\ \cline{2-5}  & & power possible & & \\ \hline \hline \end{tabular}
\end{table} 
Table 22: 3U CubeSat Product Design Specification. incorporating a 3 axis magnetorquer and reaction wheel AD&C system. When carrying the RAVAN payload, it is necessary to perform orbital maneuvers (Table 23). This acts as the justification for the incorporation of a propulsion sub-system. The payload is also required to operate between an altitude of 550 km and 600 km, presenting the need for altitude adjustment maneuvers [58]. As stated in Section 3.3.3 propellants less systems, for example solar sails, are suited to deep space exploration to other Planets such as Mars. This is due to the build-up on moment over time these systems generate, and their ability to draw energy from a renewable source [8].