Entry guidance with an improved drag profile update method is presented. The guidance method is a variation of Shuttle entry guidance in which the parameters that define the drag profile are modified to make the drag profile smooth and easier to customize. In general, in order to account for off-nominal entry conditions and ensure the vehicle flies the correct range, the nominal reference drag profile is modified online utilizing a first order approximation. This new profile is then used to calculate a reference drag command in the subsequent guidance algorithm cycle. Typical implementations of Shuttle entry guidance modify the drag profile using only one variable to shift the profile by a constant value. The methods by which the drag profile is updated are changed in order to provide multiple perturbation options. In providing multiple drag profile update parameters, an allocator is implemented with a vector of weights as a design variable. The resulting algorithm seeks to leverage the high-TRL Shuttle entry guidance routine by making minimal modifications to the implementation, while increasing robustness to dispersions under tight constraints. A discussion of drag profile design, including allocator parameter selection, is explored. Results for two highly constrained examples are presented, demonstrating the utility of this method.