# Novel 3U Stand-Alone CubeSat Architecture for Autonomous Near Earth Asteroid Fly-By
## 5 Results--Instantiated Architecture
The table reports the configuration with and without payload, in order to make clear the available mass and volume available for a custom payload. Clearly, for volume budget, only the components placed inside the structure have been considered; solar panels are folded respectively on two 1U \(\times\) 3U external faces. Recalling Figure 4, the propulsion system is able to deliver 385 m/s to a CubeSat with approximately 3900 kg BOL mass, it is clear that the mass budget is more critical than the volume one. From the first section of Table 7, it can be seen that less than 400 g and around 1U are available for the payload. The proposed payload (second section of the table) is within 1U and 400 g. Moreover, no information is available for the solar panels deployments mechanism, which would add mass to the spacecraft. However, since a 5% margin on each component dry mass, and a 10% margin on the total dry mass, have been included, the additional mass is not seen as a problem. This margin is enough to include \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Manufacturer** & **Component** & **Subsystem** & **Mass [g]** & **Volume [U]** \\ \hline Endurosat & 3U Structure & - & 285 & 3 \\ Aerojet Rocketdyne & MPS-130 1U & Propulsion & 1700 & 1 \\ GompSpace & P31u & 200 & Power & \(\sim\)0.18 \\ MMA Design & HaWk 17 AS42 & Power & \(\sim\) 300 & 3 (2D) \(\times\) 2 \\ Hyperion Technologies & iADCS200 & ADCS & 400 & 0.3 \\ Hyperion Technologies & SS200 (x6) & ADCS & 18 & \(\sim\)0.007 \\ AAC Clyde Space & Pulsar Data & Communication & 130 & \(\sim\)0.1 \\ Endurosat & 4x4 Patch antenna & Communication & 53 & \(\sim\)0.07 \\ Hyperion Technologies & CP400.85 & OBDH & 7 & 0.01 \\ Hyperion Technologies & GNSS200 & Navigation & 3 & \(\sim\)0.001 \\ \hline  & Total & - & 3076 & \(<\)2 \\  & \(+5\)\% on each & - & 3220 & \" \\  & component dry mass & - & 3483 & \" \\  & \(+10\)\% on total dry mass & - & 3897 & \" \\ \hline Hyperion Technologies & IM200 & Payload & 59 & 0.063 \\ Thoth Technologies & Argus 2000 & Payload & 300 & \(\sim\)0.3 \\ \hline  & Total & - & 3435 & \(<\)3 \\  & \(+5\)\% on each & - & 3598 & \" \\  & component dry mass & - & 3897 & \" \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Mass and volume budgets. Figure 9: Volume budgets for Delfi-n3 Xt, INSPIRE, and the instantiated architecture (from left to right). all the possible mass increase of the configuration, if off-the-shelf components are used. In order to limit the mass budget criticality, three solutions may be considered:  
1. Consider a custom payload (as it as been suggested in the Payload section);
2. Remove magnetorquers from the ADCS to lower the mass;
3. Allow a smaller \(\Delta V\) (360-370 m/s). Option 1 ensures a more customized scientific phase, but the mass constraint (below 400 g) increases the complexity of the design. Option 2 appears, as of today, as the best solution since magnetorquers can be used only in the early stages of the mission and especially for de-spinning purposes, which can eventually rely on reaction wheels. Option 3 is not recommended since it would lead to a reduction of the number of reachable targets. Recalling the 3U CubeSat architectures described in Section 2 and reported in Figure 9, the differences are evident. First, a large portion (1U) of the bus is occupied by the propulsion system, that for this architecture plays the fundamental role of controlling the CubeSat's trajectory. Then, the propulsive maneuvers require larger power demand, which converts in the need of larger deployable and orientable solar panels. Additionally, the use of integrated off-the-shelf systems allow to have dedicated processor units for many components. Moreover, one of the main difference relates to the use of the same component/subsystem to accomplish more than one function.