  Additive manufacture (AM) involves creating a part layer by layer and is a
rapidly evolving manufacturing process. It has multiple strengths that apply to
space-based optics, such as the ability to consolidate multiple parts into one,
reducing the number of interfaces. The process also allows for greater mass
reduction, making parts more cost-effective to launch, achieved by optimising
the shape for intended use or creating intricate geometries like lattices.
However, previous studies have highlighted issues associated with the AM
process. For example, when trying to achieve high-precision optical surfaces on
AM parts, the latticing on the underside of mirrors can provide insufficient
support during machining, resulting in the quilting effect.
  This paper builds on previous work and explores such challenges further. This
will be implemented by investigating ways to apply AM to a deployable mirror
from a CubeSat project called A-DOT. The reflective surface has a spherical
radius of curvature of 682 mm and approximate external dimensions of 106 mm x
83 mm. The aim is to produce two mirrors that will take full advantage of AM
design benefits and account for the challenges in printing and machining a
near-net shape. The designs will have reduced mass by using selected internal
lattice designs and topology-optimised connection points, resulting in two
mirrors with mass reduction targets of 50% and 70%. Once printed in aluminium
using laser powder bed fusion, the reflective surface will be created using
single point diamond turning. Finally, an evaluation of the dimensional
accuracy will be conducted, using interferometry, to quantify the performance
of the reflective surface.
