**Article details**

**Title: **A Mathematical Model for Computing the Trajectories of Rockets in a Resistant Medium Taking into Account the Earthâ€™s Rotation. Part 1: The Vector Equation of Rocketâ€™s Motion with Respect to the Earth. The Position of the Rocket with Respect to an Earth-Linked Geocentric Frame

**Author(s): ***Florentin Moraru* *LaurenÅ£iu Moraru* *Bogdan Scobeniuc*

**Abstract: **This paper establishes the system of ordinary equations of the trajectory of a rocket with respect to the Earth, while taking into account the aerodynamic drag, the weight, and the Earthâ€™s rotation and curvature. The local latitude and the longitude during the flight, which implicitly appears in the expressions of the forces acting upon the rocket, are determined as well. The mathematical model obtained is formalized for ballistics. This system of equations can also be used for the calculation of the trajectory of an active-reactive projectile, and also, with some adjustments, for the calculation of the trajectory of an aerospace vehicle.

**Keywords: **rocket, Earthâ€™s rotation, trajectory, rocketâ€™s latitude and longitude.

** References: **

[1] H. MOLITZ, R. STROBEL â€“* Exterior Ballistics*, Springer-Verlag, Berlin, Germany, 1963 (in German)

[2] F. MORARU â€“* Exterior Ballistics and Rocketâ€™s Flight Dynamics*, Military Academy Publishing House, Bucharest, Romania, 1973 (in Romanian)

[3] F. MORARU â€“* Handbook of Exterior Ballistics*, Military Publishing House, Bucharest, Romania, 1976 (in Romanian)

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[5] M.M. NIÅ¢Ä‚, D.Åžt. ANDREESCU â€“* The Guided and Unguided Rocketâ€™s Flight*, Military Publishing House, Bucharest, Romania, 1964 (in Romanian)

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