## 4 Discussion
### Discussion of the Results of the Analysis of the Possible Change in Inclination
* Higher specific impulse leads to a reduction in the required amount of fuel. This results from a higher effective exhaust velocity, which improves the efficiency of the thruster. * Higher effective exhaust velocity leads to a reduction in the required amount of fuel. * The value of the total increase in velocity remains constant, regardless of the weight of the satellite or other parameters, since it is determined by the geometry and altitude of the orbits. * Higher values of specific impulse lead to a significant reduction in the required amount of fuel; an increase in specific impulse by 10 s allows for a reduction in fuel demand by approximately 15 g, which is essential for missions with limited weight resources, such as nanosatellites. * The optimum choice for satellites weighing up to 15 kg are propulsion systems with a high specific impulse to minimise the weight of fuel. Discussion of the Comparative Analysis of Hohmann Transfers and Inclination Change Maneeuvres in Terms of Energy Requirements and Mission Efficiency  
Based on the previous analysis of both types of manoeuvres, a qualitative comparison was conducted to evaluate the trade-offs between the velocity increment requirement (\(\Delta\
u\)) and operational benefits. Table 13 presents the main characteristics of each strategy in the context of constraints typical for nanosatellite missions. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of Orbital** & **Demand for** & **Impact on Flight Time** & **Flexibility of** & **Comments** \\
**Manoeuvre** & **Speed Change** & **and AOI** & **Land Cover** & \\ \hline Hohmann manoeuvre & Low & Slightly extended (due to lower velocity in & Restricted (ground & Simple, energy-efficient, extends observation time \\ (in one plane) & (\(\sim 50\)–\(100\ \frac{\text{m}}{\text{s}}\)) & higher orbit) & track unchanged) & Simple, energy-efficient, extends observation time \\ \hline Change in inclinations & Very high & Varies (depending on direction and extent of change) & High (change in geometry of ground track) & Costly, justified only by the requirements of the specific mission \\ \hline \hline \end{tabular}
\end{table} 
Table 13: Qualitative comparison of Hohmann transfers and inclination change manoeuvres in the context of nanosatellite missions. The analysis included the Hohmann transfer as one of the realistic strategies for orbital altitude changes in nanosatellite missions. This manoeuvre is widely used due to its simplicity, low energy cost, and feasibility with limited fuel resources, making it particularly suitable for small satellite platforms. Changing orbital altitude directly affects the satellite's orbital velocity; the higher the orbit, the lower the velocity, which translates into an extended overpass time over the area of interest (AOI). This enables a longer observation of a selected region during a single pass. An alternative strategy is the inclination change manoeuvre, which allows for achieving more favourable geographical coverage by modifying the orbital path geometry. However, it should be noted that this type of manoeuvre requires a very high velocity change (\(\Delta\)v), often exceeding 100 \(\frac{\mathrm{m}}{\mathrm{s}}\) for each degree of inclination change. In the context of nanosatellites, which have limited fuel and energy budgets, performing such a maneuver can be challenging. For this reason, this study presents a qualitative comparison of both manoeuvring strategies, highlighting the trade-off between energy efficiency and mission effectiveness. In many cases, the Hohmann transfer proves to be a more cost-effective solution, offering significant operational benefits, such as extended observation time at a lower energy cost. On the other hand, the inclination change manoeuvre, despite its higher costs, may be justified for missions requiring a precise coverage of specific geographical areas, particularly those with irregular distributions.