Powder components subjected to pressure-less sintering ideally homogeneously shrink and retain their original shapes. However, real-world materials processing is influenced by many factors (e.g. temperature non-uniformity, external friction forces, and gravity) which during sintering produce inhomogeneous densification and shape distortions in the final component. With the increasing interest in space exploration and planet colonization, the research and advancement in producing components and repairing in space conditions gain fundamental importance. During sintering, gravity imposes a non-uniform stress which, through its influence on pore buoyancy, grain compression, and substrate friction, affects the sintering densification, microstructure, properties, and dimensional uniformity. Ground-based and extraterrestrial sintering experiments on the liquid-phase sintering of tungsten heavy alloys are conducted, allowing to obtain densification and distortion data useful for extracting constitutive parameters needed to map the sintering response with and without gravity. It is shown that such models can enable predictions relevant to space-based repair and additive manufacturing.