Complex plasmas are low temperature plasmas 1 that contain microparticles in addition to ions, electrons, and 2 neutral particles. The microparticles acquire high charges, 3 interact with each other and can be considered as model par-4 ticles for effects in classical condensed matter systems, such 5 as crystallization and fluid dynamics. In contrast to atoms in 6 ordinary systems, their movement can be traced on the most 7 basic level, that of individual particles. In order to avoid dis-8 turbances caused by gravity, experiments on complex plas-9 mas are often performed under microgravity conditions. The 10 PK-3 Plus Laboratory was operated on board the Interna-11 tional Space Station from 2006 -2013. Its heart consisted of 12 a capacitively coupled radio-frequency plasma chamber. Mi-13 croparticles were inserted into the low-temperature plasma, 14 forming large, homogeneous complex plasma clouds. Here, 15 we review the results obtained with recent analyses of PK-3 16 Plus data: We study the formation of crystallization fronts, 17 as well as the microparticle motion in, and structure of crys-18 talline complex plasmas. We investigate fluid effects such as 19 wave transmission across an interface, and the development 20 of the energy spectra during the onset of turbulent micropar-ticle movement. We explore how abnormal particles move 22 through, and how macroscopic spheres interact with the mi-23 croparticle cloud. These examples demonstrate the versatil-24 ity of the PK-3 Plus Laboratory. 25 28 53 Weightless complex plasmas show a wealth of interest-1 ing phenomena such as relatively stress-free crystallization 2 [9,14], waves [15, 16], lane formation [17, 18], electrorhe-3 ology and string formation [19-22], cavitation and Mach 4 cones [23-25], etc. Laboratories to study complex plasmas 5 were already used on board the Mir space station [26], and 6 were among the first scientific experiments on board the In-7 ternational Space Station (ISS) [9]. The Russian-German 8 PK-3 Plus Laboratory was operated on the ISS from 2006 9 -2013 [27-29], and the state-of-the-art Russian-European 10 PK-4 Laboratory is currently on board [30, 31]. Data analy-11 sis from PK-3 Plus is still on-going, and here we will review 12 some of the latest results. 13 Fig. 1 shows a sketch of the heart of the PK-3 Plus Lab-14 oratory, the plasma chamber. A plasma was produced in a 15 vacuum chamber filled with argon or neon gas at pressures 16 between 5 and 255 Pa by applying a radio-frequency elec-17 tric field to two parallel electrodes with a distance of 3 cm 18 and a radius of 6 cm. The electrodes were surrounded by 19 1.5 cm wide grounded guard rings in which particle dis-20 pensers were embedded. The dispensers were shaken elec-21 tromagnetically in order to inject monodisperse silica and 22 78