Orbit Sensitivity Analysis for Catarina Constellation

The Brazilian Data Collection System (SBCD) currently relies on geostationary satellites to gather environmental data and provide climate and defense analyses in Brazilian territory. However, due to the high costs associated with large satellite missions, the development of CubeSats - small, cost-effective satellites - has become a more attractive option for both companies and universities. As a result, the Catarina Constellation project was established to create a constellation of nanosatellites that would significantly improve remote sensing capabilities, stimulate the growth of the space industry in Santa Catarina, and foster collaboration between industry, government, and universities. To ensure the success of the Catarina Constellation project and due to launch uncertainties, a sensitivity analysis was conducted on the inclination, altitude, and right ascension of the ascending node of the orbit. This analysis aimed to determine the impact of these variations on specific mission parameters, including the number of times communication is established, the time the communication between the nanosatellite and the ground station, and the evaluation of days when communication is established. Using an orbital propagation code developed by the authors, a series of simulations were conducted to perturb the orbital parameters within a margin of error of +/- 25 km (±0.4%) for the semi-major axis, +/- 5 degrees (±5%) for the inclination, and +/- 10 degrees (±5%) for the right ascension of the ascending node. From this data the results in a variation of 25% in the contact time and the average communication time, and a variation of 20% in the number of passes.