## 4 Results  
This section demonstrates the feasibility of using standard LoRa parameters in satellite constellations in LEO orbits for IoT communications on Mars through a detailed use case simulation (see Table 3). The revisit and visibility times of the IoT nodes are also evaluated according to the configuration of the satellite constellation, the transmission distance, the message processing capacity of the satellites, and the interplanetary data communications between Mars and the Earth. To calculate revisit times and the visibility of IoT nodes, several commercial applications are used for the satellite dynamics' simulation [50]; among them is the System Tool Kit (STK) software [2], which is used in this work. To complete this study, STK analyzed Martian orbiter trajectories precisely, considering various factors that affect satellite motion. After establishing the required orbital propagations and communication links within STK, the data were exported to comma-separated value (CSV) files for further handling. Various key metrics were examined during the post-processing phase of the data analysis. One of these metrics is the visibility time of satellites. It measures the duration between the initiation and termination of contact between a satellite from the constellation and an IoT node located on the surface of Mars. Another metric is the revisit time, which refers to the duration required for a Mars orbiter to pass over a specific IoT node on Mars again. These metrics are crucial for assessing the viability and reliability of communications between the satellite constellation and IoT nodes on the Mars surface and are discussed below. The code for creating the STK scenario, exporting the data, and processing and plotting the results can be seen in the repository of the Data Availability Statement. \begin{table}
\begin{tabular}{l l l l l l l} \hline \hline
**Semi-Major** & **Altitude** & **Eccentricity** & **Inclination** & **T. Anom. ** & **RAAN** & **Arg. of P.** \\
**Axis (km)** & **(km)** & **Eccentricity** & **(Degrees)** & **(Degrees)** & **(Degrees)** & **(Degrees)** \\ \hline
3496 & 100 & 0 & 30 & 0 & 0 & 0 \\ \hline
3496 & 100 & 0 &  
The bar plot in Figure 6 provides a comprehensive overview of the contact duration between a set of IoT nodes at various latitudes on Mars and a constellation of satellites in different orbital configurations. The contact duration is when a satellite remains in direct line-of-sight with an IoT node, facilitating uninterrupted communication. Each subplot corresponds to a different IoT node at 0-, 30-, 6-, and 90-degree latitudes, respectively. The satellites are categorized by altitude (100, 500, 900, and 1300 km) and inclination (0, 30, 60, and 90 degrees), with the bars color-coded to distinguish between the altitudes. Analysis of the plots indicates that higher-altitude satellites generally provide longer contact durations due to their broader line-of-sight horizons. The most extended average contact times are observed with the satellite at a 1300 km altitude and 90-degree inclination, highlighting the impact of higher vantage points and polar orbit paths on communication windows. Conversely, satellites at lower altitudes tend to have shorter contact durations due to their closer proximity and faster orbital velocity, resulting in quicker transits across the IoT node's sky. Notably, the inclination of the satellites also plays a significant role, with those in equatorial orbits (0-degree inclination) demonstrating the shortest contact times, particularly for IoT nodes situated at the poles. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{ \begin{tabular}{c} **Constellation No.** \\ \end{tabular}  } & \multirow{2}{*}{**No. Satellites**} & \multirow{2}{*}{**Orbital**} & \multirow{2}{*}{ \begin{tabular}{c} **IoT Node** \\ **Planes** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Revisit Time** \\ **(Minutes)** \\ **(Degrees)** \\ \end{tabular}  } & \multirow{2}{*}{