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The purpose of this paper is to propose a new guidance algorithm for launching a satellite using an expendable rocket from an equatorial site to an equatorial low‐Earth orbit.

Guidance during endoatmospheric portion is based on a nominal trajectory computed prior to take‐off. A set of updating computations begins anew at the time instant t_g of transition from endoatmosphere to exoatmosphere. The updating computations determine a guidance trajectory and an associated control law for the remainder of path by taking into account the rocket state at time t_g. Thus, the overall guidance involves both initial and midcourse operations, and it has both open‐ and closed‐loop aspects.

Viability and performance in terms of speed, precision, and effectiveness of the proposed scheme is demonstrated through three‐dimensional simulations and comparisons to other methods.

The updating computations and the fashion in which they are incorporated into the entire guidance process constitute the novel features of the proposed algorithm.