# Design of Novel Laser Crosslink Systems Using Nanosatellites in Formation Flying: The VISION
## 6 Conclusions  
This study proposed design schemes for novel laser crosslink systems with a 6U nanosatellite platform, including formation flying mission scenarios and system design specifications. The aim of the VISION mission is to establish a miniaturized laser crosslink with a 1 Gbps level of super-high-speed data transfer at an inter-satellite distance of 1000 km. Additionally, several space technologies, such as deployable space telescopes, were proposed for future applications. The laser crosslink mission scenarios were presented in \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Operating Temperature (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Worst Case Analysis (\({}^{\circ}\)C)**} \\ \cline{2-5}  & **Subsystem** & **Min.** & **Max.** & **Min.** & **Max.** \\ \hline
**Payload** & Laser Communication Terminal & \(-40\) & \(+85\) & \(20.37\) & \(23.71\) \\ \hline \multirow{3}{*}{**GNC**} & Integrated ADCS & \(-20\) & \(+50\) & \(21.32\) & \(22.61\) \\  & GNSS Antenna & \(-40\) & \(+85\) & \(23.41\) & \(25.00\) \\  & Propulsion & \(0\) & \(+50\) & \(20.33\) & \(25.40\) \\ \hline \multirow{3}{*}{**CDHS**} & Primary OBC and GNSS Receiver & \(-40\) & \(+85\) & \(24.28\) & \(25.70\) \\  & Secondary OBC and UHF Transceiver & \(-30\) & \(+85\) & \(23.81\) & \(25.30\) \\ \hline \multirow{3}{*}{**COMS**} & S-band SDR & \(-40\) & \(+85\) & \(23.87\) & \(25.48\) \\  & S-band Antenna (TMTC) & \(-40\) & \(+85\) & \(11.53\) & \(16.09\) \\ \cline{1-1}  & S-band Antenna (Crosslink) & \(-40\) & \(+85\) & \(23.21\) & \(24.85\) \\ \cline{1-1}  & X-band SDR & \(-40\) & \(+85\) & \(20.50\) & \(21.48\) \\ \cline{1-1}  & X-band Transmitter and Antenna & \(-40\) & \(+57\) & \(20.38\) & \(22.42\) \\ \cline{1-1}  & UHF Antenna & \(-40\) & \(+85\) & \(12.68\) & \(17.50\) \\ \hline \multirow{3}{*}{**EPS**} & Solar Panel & \(-40\) & \(+105\) & \(-27.83\) & \(83.08\) \\ \cline{1-1}  & PCDU & \(-35\) & \(+85\) & \(21.35\) & \(22.40\) \\ \cline{1-1}  & Battery & \(0\) & \(+45\) & \(20.37\) & \(23.74\) \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Summary of thermal analysis results for worst hottest and coldest cases. Figure 20: Exterior temperature contours of on-orbit thermal analysis for worst hottest and coldest case. The worst hottest case is for maximum solar flux and internal heat loads. The worst coldest case is for minimum solar flux and internal heat loads: (**a**) solar irradiance conditions for the summer season which have eclipse periods; (**b**) solar irradiance conditions without eclipse periods. detail from link access to maintenance. An optical link budget analysis was conducted to evaluate system performance. The main contribution of this study is the advancement of spaceborne laser communication systems. The nanosatellites in formation flying and laser crosslink payloads were designed to meet the system requirements under practical limitations utilizing commercial off-the shelf products, which would reduce the cost and effort of system performance evaluation and on-ground verification. In addition, fundamental technologies for space optics were proposed for the sensing of remote areas with super-high resolution. Moreover, owing to their precise formation flying technologies, including orbit maneuvering capabilities, the proposed nanosatellite systems can be utilized as platforms for mega-constellation applications. These preliminary systems are under development in accordance with the Engineering and Qualification Model (EQM) philosophy. A prototype of the payload was developed. The prototype is expected to demonstrate the on-orbit performance of laser crosslink and PAT using a far-field hardware testbed which can emulate disturbances such as pointing errors and jitter. In addition, the electrical testbed (ETB) of the bus was constructed to test the electrical interfaces among components. An end-to-end (ETE) testing with the FSW is being planned for this year. Conceptualization, G.-N.K., S.S., J.-Y.C., S.-K.H. and S.-Y.P. ; methodology, G.-N.K., S.S., J.-Y.C. and S.-K.H.