  We present the technical realization of a compact system for performing
experiments with cold $^{87}{\text{Rb}}$ and $^{39}{\text{K}}$ atoms in
microgravity in the future. The whole system fits into a capsule to be used in
the drop tower Bremen. One of the advantages of a microgravity environment is
long time evolution of atomic clouds which yields higher sensitivities in atom
interferometer measurements. We give a full description of the system
containing an experimental chamber with ultra-high vacuum conditions,
miniaturized laser systems, a high-power thulium-doped fiber laser, the
electronics and the power management. In a two-stage magneto-optical trap atoms
should be cooled to the low $\mu$K regime. The thulium-doped fiber laser will
create an optical dipole trap which will allow further cooling to sub-$\mu$K
temperatures. The presented system fulfills the demanding requirements on size
and power management for cold atom experiments on a microgravity platform,
especially with respect to the use of an optical dipole trap. A first test in
microgravity, including the creation of a cold Rb ensemble, shows the
functionality of the system.
