Planning is based on prioritizing certain major science goals over 2 week periods. These are broken down into four Discipline groups (DGs). DG1 looks at global nucleus characterization, morphology and composition. DG 2 looks at chemistry and mineralogy, isotopic composition of volatiles, and refractories of the nucleus. DG3 looks at physical properties and interrelations between volatiles and refractories. DG4 looks at activity and its development. For this close fly by [on February 14 at an altitude of 6 kilometers], DG1 were "prime" -- they are looking at getting the best measurements of the surface properties at a wide range of phase angles. We will fly through the sub solar point to enable this. [That is, they will pass directly between the Sun and the comet, getting a "zero phase" view of the comet.] We will also be making valuable in -situ measurements during this passage, hopefully getting a feel for the acceleration region, where the coma is "born", where the dust grains acquire their terminal velocity from exchange of momentum with gas molecules. Such mechanisms have only been modelled theoretically so far. The rest of the trajectory arcs are there to link up with the next fly by (which will be a far fly by, approximately sub-solar at approximately 50 km) again focused on DG1 goals.