# Agile Stage-Gate Approach for Design, Integration, and Testing of a 1U CubeSat
## 3 Results  
### Environmental Tests  
Testing activities were broken down into categories according to our integration and testing flow diagram. The environmental tests enabled us to determine a solution linking validation testing with success using an Agile Stage-Gate approach for a nanosatellite in a real environment. This study shows that the time spent in design, including prototyping and early testing, is linked to a higher probability of success. The vibration test consisted of three phases. In the first phase, the spacecraft (off) was placed on a transverse axis to the vibration table within the storage configuration launch vehicle adapter, and a sine sweep was performed to obtain a baseline of the system on that axis (Figure 11). Figure 11 illustrates the results of the test on a logarithmic scale where the \begin{table}
\begin{tabular}{c c c} \hline
**No.** & **Sensor** & **Location** \\ \hline
1 & Thermocouple 1 & Plate \\ \hline
2 & Thermocouple 2 & Side wall \\ \hline
3 & Thermocouple 3 & Shroud top \\ \hline
4 & Thermocouple 4 & AztechSat-1 satellite, external (\(Z\)- Solar panel) \\ \hline
5 & Thermocouple 5 & AztechSat-1 satellite, external (\(X\)+ Structure Rail down) \\ \hline
6 & Thermocouple 6 & AztechSat-1 satellite, external (\(Y\)+ Solar panel) \\ \hline
7 & Thermocouple 7 & AztechSat-1 satellite, external (\(Y\)- Solar panel) \\ \hline
8 & Thermocouple 8 & AztechSat-1 satellite, external (\(X\)- Structure Rail up) \\ \hline
9 & Thermocouple 9 & AztechSat-1 satellite, internal (\(Z\)+ intersatellite module) \\ \hline \end{tabular}
\end{table} 
Table 4: Temperature sensor and position for thermal testing. Figure 10: Visual timeline of TVPM temperature profile. \(x\) axis indicates the frequency in Hertz, and the \(y\) axis indicates acceleration in g for each axis of the nanosatellite. In the second phase, random vibrations were executed with the values provided by the launcher in the same axis as before (Figure 12). Finally, a sine sweep was again performed (Figure 13) and compared with the first sweep to note differences. As we did not observe any substantial differences, a functional check was completed after all runs to ensure satellite functionality before delivery to the launch provider. For this purpose, a test pod was used to simulate the conditions of the nanosatellite during launch. The test was performed at the Ames Research Center. The vibration setup is shown in Figure 14. For the \(y\) and \(x\) axes, the nanosatellite was rotated 90 degrees. For the \(Z\) axis, the nanosatellite was removed completely from the system and then mounted in the desired position. Figures 10 and 12 indicate a difference of less than 1% compared to the control line on the \(Z\) axis. Figure 12 illustrates the PSD vibration of the entire system. A very common method used to indicate problems during random vibrations involves utilizing the PSD. The method used to evaluate acceleration, which changes constantly, involves comparing the average values. The root mean square value, or Grms, must remain similar. Here, frequencies below 200 Hz were attributed to the vibrations of the table setup. Figure 12 denotes the responses for only one axis. However, all tests yielded results within the necessary range. The yellow lines indicate alarm parameters, and the red lines indicate abort parameters. A post-sine vibration test was performed to confirm the absence of resonance frequencies in the test range. No acceleration peaks were observed, and there was no damage on the nanosatellite after the test. As the AztechSat-1 nanosatellite was deployed from the ISS, the path of the ISS was considered for thermal parameters. For thermal testing, a vacuum chamber was needed. The equipment used for this test belonged to the NASA Ames Research Center. The thermal environment's testing conditions did not yield any complications for the system's operations. A cold/hot cycle was completed with no damage to the system. The results are  
Figure 11: Sine sweep vibration test (baseline).