Complex plasma research on ISS: PK-3 Plus, PK-4 and impact/plasmalab

Complex plasma research under microgravity conditions is one of the present key research topics in fundamental physics and material science on the International Space Station, ISS. In 2001 the so-called PKE-Nefedov facility performed its first experiments in radiofrequency induced complex plasmas. This bilateral German–Russian research facility operated successfully in over 13 missions nearly five years until its internal resources were consumed—resulting so far in over 30 peer-reviewed scientific publications. The next generation experiment apparatus PK-3 Plus with refined and more powerful instruments and diagnostics had its on-orbit commissioning in January 2006. It is performing flawlessly since then and has already been successfully employed during various ISS increments including Russian cosmonauts and ESA astronaut Thomas Reiter. The next generation of plasma research facilities on the ISS is the European–German–Russian PK-4 facility presently under development to investigate direct current induced complex plasmas. PK-4 is planned to be launched at the end of 2009 with the C/D development phase starting in 2007. Plans and studies to continue these research topics after PK-4 are already ongoing. Scientific next generation complex plasma research inserts may be either a part of the IMPACT (International Multi-User Plasma, Atmospheric and Cosmic Dust Twin) research laboratory in the ESA Columbus Module or more likely, part of a multi-purpose accommodation site titled “Plasma Laboratory” in the new Russian research module “MLM” scheduled for launch in 2009. The paper first presents some key results from the PK-3 Plus sessions on the ISS in 2006 and 2007. Second, the paper summarizes the status of PK-4 and highlights future potential research fields/inserts for “Plasma Lab”.