  The future of space exploration missions will rely on technologies increasing
their endurance and self-sufficiency, including for manufacturing objects
on-demand. We propose a process for handling and additively manufacturing
powders that functions independently of the gravitational environment and with
no restriction on feedstock powder flowability. Based on a specific sequence of
boundary loads applied to the granular packing, powder is transported to the
printing zone, homogenized and put under compression to increase the density of
the final part. The powder deposition process is validated by simulations that
show the homogeneity and density of deposition to be insensitive to gravity and
cohesion forces within the DEM model. We further provide an experimental proof
of concept of the process by successfully 3D printing parts on-ground and in
weightlessness, on parabolic flight. Powders exhibiting high and low
flowability are used as model feedstock material to demonstrate the versatility
of the process, opening the way for additive manufacturing of recycled
material.
