Metal 3D printing (aka Additive Manufacturing) is a major component of the fourth industrial revolution. This disruptive fabrication method allows for high performance metal waveguide antennas, a critical part of any satellite, to be reduced to their minimum size and weight. Metal waveguide RF structures have the lowest loss and are the ideal choice for a high performance satellite antenna. Metal 3D printing allows for highly complex parts to be interwoven in a single solid structure and printed repeatedly with overall reduced size, weight, and cost. This presentation will cover how Metal 3D printing will usher in an era of mass customization, where the constrained volume remaining in a satellite can be filled with a unique high performance antenna that conforms to the space around it and provides a lower loss, higher performance solution than any competing alternative.