The paper presents a fluid structure interaction based numerical study of impact loading for a hemispherical structure upon water and a space capsule water landing. The study has a strong relevance in the determination of the crashworthiness of aerospace structures upon water impact loading. Finite element based numerical techniques have been used for the analysis of the underlying transient dynamic and fluid-structure interaction. Smoothed Particle Hydrodynamics (SPH) and Arbitrary Lagrange-Eulerian (ALE) methods have been used to simulate the behaviour of the fluid (water) under impact conditions. The accelerations and velocities of the impacting objects have been validated with by experimental measurements and analytical results. Numerical analyses showed a strong potential for the use of developed computational fluid structure interaction models for analyses of water impact loading related problems.