FELs promise major breakthroughs in different scientific areas that range from atomic, molceular and optical (AMO) physics, femto-chemistry through clusters to condensed matter and biological studies. At the same time, the new machines pose extremely high demands on any experimental instrumentation aiming at fully exploiting their potential,. The challenges include recording at up to 5 MHz frame readout rates for large area x-ray photon CCD imagers and detection of hundreds of electrons and ions per shot, often simultaneously with photons. To fully understand the many-particle dynamics occurring when FEL radiation hits matter, a close interaction between theory and experiment, between researchers in physics, chemistry and biology, between scientists and detector developers is required. The ASG covers all of these aspects in a unique combination.