3D printing offers unprecedented capabilities and solutions to challenges inherent in extraterrestrial environments. In particular 3D printing of metallic materials by means of laser melting places high demands on the processing methods. While on Earth, the optimization of the process parameters is well studied and technically mastered in many cases, the behaviour under reduced gravity and weightlessness is largely unknown. By means of Smoothed Particle Hydrodynamics (SPH) simulations we therefore show, how the dynamics of laser-melted metals depend on gravity (Fig. 1). Our simulations make it possible to investigate the phenomena relevant to the manufacturing process cost-effectively under variable gravity and can thus make an important contribution to the development of techniques for additive manufacturing under conditions of weightlessness and reduced gravity.