<p> We propose to develop a new highly sensitive instrument to confirm the existence of the so-called nano-dust particles, characterize their impact parameters, and measure their chemical composition. Simultaneous theoretical studies will be used to derive the expected mass and velocity ranges of these putative particles to formulate science and measurement requirements for the future deployment of the proposed Nano-Dust Analyzer (NDA) </p> <p> Early dust instruments onboard Pioneer 8 and 9 and Helios spacecraft detected a flow of submicron sized dust particles coming from the direction of the Sun. These particles originate in the inner solar system from mutual collisions among meteoroids and move on hyperbolic orbits that leave the Solar System under the prevailing radiation pressure force. Later dust instruments with higher sensitivity had to avoid looking toward the Sun because of interference from the solar wind and UV radiation and thus contributed little to the characterization of the dust stream. The one exception is the Ulysses dust detector that observed escaping dust particles high above the solar poles, which confirm the suspicion that charged nanometer sized dust grains are carried to high heliographic latitudes by electromagnetic interactions with the Interplanetary Magnetic Field (IMF). Recently, the STEREO WAVES instruments recorded a large number of intense electric field signals, which were interpreted as impacts from nanometer sized particles striking the spacecraft with velocities of about the solar wind speed. This high flux and strong spatial and/or temporal variations of nanometer sized dust grains at low latitude appears to be uncorrelated with the solar wind properties. This is a mystery as it would require that the total collisional meteoroid debris inside 1 AU is cast in nanometer sized fragments. The observed fluxes of inner-source pickup ions also point to the existence of a much enhanced dust population in the nanometer size range. </p> <p> This new heliospherical phenomenon of nano-dust streams may have consequences throughout the planetary system, but as of yet no dust instrument exists that could be used to shed light on their properties. We propose to develop a dust analyzer capable to detect and analyze these mysterious dust particles coming from the solar direction and to embark upon complementary theoretical studies to understand their characteristics. The instrument is based on the Cassini Dust Analyzer (CDA) that has analyzed the composition of nanometer sized dust particles emanating from the Jovian and Saturnian systems but could not be pointed towards the Sun. By applying technologies implemented in solar wind instruments and coronagraphs a highly sensitive dust analyzer will be developed and tested in the laboratory. The dust analyzer shall be able to characterize impact properties (impact charge and energy distribution of ions from which mass and speed of the impacting grains may be derived) and chemical composition of individual nanometer sized particles while exposed to solar wind and UV radiation. The measurements will enable us to identify the source of the dust by comparing their elemental composition with that of larger micrometeoroid particles of cometary and asteroid origin and will reveal interaction of nano-dust with the interplanetary medium by investigating the relation of the dust flux with solar wind and IMF properties. </p> <p> Complementary theoretically studies will be performed to understand the characteristics of nano-dust particles at 1 AU to answer the following questions: - What is the speed range at which nanometer sized particles impact a spacecraft at 1 AU? - From what direction these particles impact at a spacecraft at 1 AU? This has implications on the field-of-view of the instrument. - What is the flux of particles at 1 AU assuming a break-up of approximately 10 tons/sec of cosmic material (approx. 10^25 particles) in the inner solar system? FORM NRESS- </p>