This paper describes the current status of instrument predevelopment activities that are being performed in the frame of a potential Aeolus Follow-On mission (Aeolus-2). The main inputs for a future Doppler Wind Lidar (DWL) instrument that have been used are: lessons learned from the Aeolus development phases and the in-orbit operations and performance; initial inputs from EUMETSAT including an overall mission lifetime of 10–15 years utilizing 2–3 spacecraft (implying a lifetime of 5 years or more for each) with a launch of the first satellite in 2029, increased robustness and operability of the instrument, and an emphasis on reduction of recurrent costs; the maximum utilization of the demonstrated design heritage; and a number of recommendations for the requirements of a future DWL mission from the Aeolus Scientific Advisory Group (ASAG). These inputs have been collated and combined into a set of preliminary system requirements which have been used as the basis for a dedicated Instrument Consolidation Study. In addition, three instrument subsystem pre-development activities have been kicked-off: two laser transmitter pre-developments and the predevelopment of an improved detector. These developments have the aim to demonstrate that issues identified from the above are resolved and that the technology levels are sufficiently mature for the follow-on DWL mission.