1. The Science of Solar B Transient phenomena – this aim covers the wide ranges of explosive phenomena observed on the Sun – from small scale flaring in the quiet Sun, to large flares, to huge ejections of material. Some of the missions goals include determining what triggers flares, and coronal mass ejections. This will ultimately feed into the currently poor space weather prediction tools. Coronal Heating – this problem has been around for many decades and huge progress has been made. We now know that the origin of this once mysterious heating is magnetic in origin. However we now need to probe this further with Solar-Bs high spatial, temporal and velocity resolution in order to distinguish between for example magnetic wave heating and small scale reconnection events. Different phenomena such as active regions, quiet Sun and coronal holes are all likely to have different heating mechanisms. Solar-B provides us with the opportunity to determine this. CORONAL HEATING, TRANSIENT PHENOMENAENERGY TRANSFER FROM THE PHOTOSPHERE TO THE CORONA. Solar B will use the combination of 3 instruments in order to provide a powerful microscope on the Sun. These are the Solar Optical Telescope (SOT), the X-ray Telescope (XRT) and the EUV Imaging Spectrometer (EIS) which provide high temporal, spatial and velocity resolution of the Sun from the surface right through to the outer atmosphere. The instruments have been developed with specific goals in mind: CORONAL HEATING, TRANSIENT PHENOMENA and ENERGY TRANSFER FROM THE PHOTOSPHERE TO THE CORONA. Energy Transfer from the photosphere to the corona – this aim encompasses all of the science goals of solar-B. We will observe the vector magnetic field with a spatial resolution of 175 km, along with high resolution images of the corona, and high resolution velocity information. We will be able to probe the causal relationship between dynamics in the photosphere and coronal phenomena. This figure shows observations made by the Norikura Observatory, Japan, which can obtain high spatial resolution with accurate measurements of velocity and line width. Solar- B will be able to do this uninterrupted in space, across a broad range of temperatures. This will allow us to distinguish between wave heating and reconnection events. This figure shows the variety of data that we will be able to obtain with Solar-B – from the visible sunspots, to the velocity field in the magnetic field, and how the atmosphere responds to these changes will all be observed. Ultimately we will be able to compare closely with the predictions of current (and future) theories in order to have a deeper understanding of this fundamental process. The figure above shows the first absolute evidence that dimming observed in the corona is directly related to outflowing material. This result was obtained with SOHO-CDS. With Solar-B, our driver has been spectral and temporal resolution, so that we will regularly observe the elusive material leaving the Sun that forms the coronal mass ejection as seen in coronagraph data. The figure above shows TRACE data of the Bastille day flare in 3 temperatures. The rapid filling up of material during the flare can be observed from the imagers. The figure below shows results from Yohkoh-BCS that demonstrate that turbulence (determined from the spectral line widths) is apparent 10 minutes before the flare begins. With solar-B, we will be able to observe the changes in turbulence and flows accurately in a build-up to a flare. The combination of high spectral resolution with imaging capability will provide us answers that have previously been unobtainable with current datasets.