The solar wind is an uninterrupted flow of highly ionised plasma that fills interplanetary space and is crossed by strong transient perturbations such as coronal mass ejections (CMEs), (corotating) stream interaction regions (SIRs), and solar energetic particles (SEPs). These phenomena are capable of driving large disturbances at Earth as well as at the other planets. Remote-sensing observations from multiple vantage points, in-situ measurements from multiple well-separated locations, and novel modelling efforts have been employed systematically to study the properties of the solar wind plasma and of solar transients in general, from their formation to their arrival at different planets throughout the inner heliosphere. However, despite the number of past and current spacecraft missions distributed throughout the heliosphere, it is still difficult to fully understand the properties of these transients phenomena, including their 3D structure and their evolution with heliocentric distance.

The recently launched Parker Solar Probe, the imminent launch of Solar Orbiter, current and planned planetary missions, as well as potential future missions at L1, L5, and over the solar poles, will provide us with the perfect opportunity to test, validate, and refine the current knowledge of these physical phenomena and their interactions at different heliocentric distances. Accordingly, the aim of this session is to showcase the latest observational and modelling efforts regarding the evolution of the solar wind and solar transients during their propagation throughout the heliosphere as seen from multiple vantage points, and to foresee future developments. Potential improvements to our current space weather forecasting capabilities will be highlighted.