Neutron capture in massive stars -- the challenge of the weak s process

Neutron capture nucleosynthesis in massive stars has regained considerable interest for the analysis of abundance patterns in very early, metal-poor halo stars as well as for a quantitative picture of galactic chemical evolution. This so-called weak component, which is responsible for the s abundances between Fe and Y, turned out to be very sensitive to the stellar neutron capture cross sections of the isotopes in this mass region. However, these data are incomplete and exhibit large discrepancies between different experiments. New facilities and experimental techniques have to be invoked to meet these challenges