# CubeSat-Based Observations of Lunar Ice Water Using a 183 GHz Horn Antenna: Design and Optimization
## 5 Project Benefits and Future Work  
In this paper, we have successfully proposed and demonstrated a cost-effective method to transform corrugated horn antennas into smooth-walled designs. The utilization of MATLAB Cubic Smoothing Splines algorithms allowed us to achieve impressive antenna performance, including enhanced gain, reduced \(S_{11}\) parameters, and improved VSWR, within the frequency range of 160 GHz to 200 GHz. We employed a commercial 3D printer with ABS material to fabricate the smooth-walled 183 GHz horn antenna, and its functionality was verified through practical experiments.  
By using copper conductive paint to coat the antenna surface, we efficiently transformed the corrugated antenna into a smooth-walled design, resulting in significant cost  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Antenna Type** & \(S_{11}\)**dB** & **VSWR** & **Gain dB** \\ \hline corrugated & \(-\)5 to \(-\)35 & 2.23 to 0.35 & 1.4 \\ Smooth & \(-\)27 to \(-\)36 & 1.01 & 18 \\ fabricated & \(-\)26 to \(-\)30 & 1.45 & \(-\) \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparison of corrugated, smooth-walled, and fabricated antenna parameters.  
Figure 12: VSWR measurement results for smooth-walled antenna.  
savings. The entire antenna fabrication cost was less than AUD 25, making it highly accessible for student projects and ground-based model testing. We also demonstrated its suitability for use in CubeSat engineering models due to its small size and excellent performance. However, we acknowledge that the copper coating may not withstand the harsh environment of outer space, limiting its application for satellite missions. Figure 13 illustrates CubeSat's operation, where the smooth-walled antenna and subharmonic receiver system will play a crucial role in measuring water on the moon. This research opens up promising avenues for the development of compact and efficient antennas for future planetary water detection missions, advancing space exploration and scientific research.  
This figure illustrates the smooth-walled horn antenna integrated into a CubeSat platform, serving as a crucial component in the remote sensing of water on the moon's surface. The smooth-walled antenna, optimized through our proposed method, exhibits enhanced performance in transmitting and receiving signals within the frequency range of 160 GHz to 200 GHz. The antenna is utilized in conjunction with a THz subharmonic receiver payload to accurately measure the presence of water on the moon. The CubeSat platform orbits the moon and captures the spectrum of the lunar surface using the smooth-walled horn antenna, allowing us to detect water spectral signatures and identify locations with potential water ice. This innovative approach holds great promise for future space missions, enabling efficient and accurate water detection on extraterrestrial bodies and further advancing our understanding of the cosmos. Figure 13 exemplifies the smooth-walled horn antenna's critical role in contributing to the success of space exploration and pioneering scientific investigations beyond our planet.