This paper presents flight control designs of an unmanned space vehicle, HOPE-X vehicle using an interpolation gain scheduling technique. The ν-gap metric is used to evaluate the errors between linear models at operating points. The linear parameter varying models for the HOPE-X vehicle were then constructed by minimizing two types of indices defined with the ν-gap metric. On the other hand, the magnitude of the input is locally constrained to avoid the saturation of the control surfaces. In the numerical simulations of the HOPE-X, the gain scheduling control laws whose number of operating points was greater than two could be applicable to the whole region of the terminal area energy management phase of the HOPE-X. Furthermore, the input constraint was effective to suppress the magnitude of the input and to extend the stability region of the design parameter.