WE ASK THE BASIC SCIENCE QUESTION: "WHAT ARE THE SHAPES AND TIME HISTORIES OF HELIOSPHERIC STRUCTURES IN THE PLASMA PARAMETERS: DENSITY AND VELOCITY" TO ANSWER THIS QUESTION WE PROPOSE TO BUILD AND TEST ASHI AN ALL-SKY HELIOSPHERIC IMAGER FOR NASA MISSIONS WHOSE PRIMARY APPLICABILITY IS TO VIEW THE INNER HELIOSPHERE FROM DEEP SPACE. THE ZODIACAL-LIGHT PHOTOMETERS ON THE TWIN HELIOS SPACECRAFT THE SOLAR MASS EJECTION IMAGER (SMEI) ON THE CORIOLIS SATELLITE AND THE HELIOSPHERIC IMAGERS (HIS) ON THE SOLAR- TERRESTRIAL RELATIONS OBSERVATORY (STEREO) TWIN SPACECRAFT ALL POINT THE WAY TOWARDS OPTIMUM INSTRUMENTS FOR THOMSON SCATTERING OBSERVATIONS FROM SPACE AND ALSO FOR FUTURE LOW-LIGHT-LEVEL AURORAL REMOTE-SENSING. THE SPECIFICATIONS FOR SUCH SYSTEMS INCLUDE VIEWING THE WHOLE SKY STARTING BEYOND A FEW DEGREES OF THE SUN AND COVERING A HEMISPHERE OR MORE OF SKY. WITH AN IMAGER MASS OF ABOUT 2.5 KG PER SYSTEM (SCALABLE TO LOWER VALUES FOR INSTRUMENTS VIEWING FROM CLOSER THAN 1 AU) TEN-MINUTE EXPOSURES 20 ARC-SECOND POINTING AND LOW POWER CONSUMPTION THIS TYPE OF INSTRUMENT HAS BEEN A POPULAR CHOICE FOR RECENT NASA MISSION CONCEPTS SUCH AS STEREO SOLAR ORBITER SOLAR PROBE AND EASCO. A KEY PHOTOMETRIC SPECIFICATION FOR SUCH IMAGERS IS 0.1% DIFFERENTIAL PHOTOMETRY WHICH ENABLES THE 3-D RECONSTRUCTION OF DENSITY STARTING FROM NEAR THE SUN AND EXTENDING OUTWARD. A PROVEN CONCEPT USING SMEI ANALYSES ASHI WILL PROVIDE AN ORDER OF MAGNITUDE BETTER RESOLUTION IN THREE DIMENSIONS OVER TIME. WE WILL INCLUDE VELOCITY THIS CONCEPT AND FOR A HELIOSPHERIC IMAGER IN DEEP SPACE PROVIDE A HIGH-RESOLUTION COMPARISON OF IN-SITU DENSITY AND VELOCITY MEASUREMENTS OBTAINED AT THE SPACECRAFT TO STRUCTURES OBSERVED REMOTELY (JACKSON ET AL. 2010 SOLAR PHYS. 265 257; JACKSON ET AL. 2011 JASTP 73 1214).WE PROPOSE TO ENHANCE THIS INSTRUMENT CONCEPT BY BUILDING SUBSYSTEMS TO MOUNT AND TEST EXISTING OPTICAL COMPONENTS WE HAVE AT UCSD THAT INCLUDE AN IN-HAND LIGHTWEIGHT DIAMOND-TURNED ALUMINIZED PRIMARY OPTIC TO PURCHASE ITS ACCOMPANYING LENS SYSTEM AND PROVIDE A LIGHTWEIGHT BAFFLE AND CONTAINER SUITABLE FOR MOUNTING ON A SPACECRAFT. ALTHOUGH CONSTRUCTION AND LABORATORY TESTS OF THE MAIN OPTICAL SYSTEM COMPONENTS AND BAFFLE HAVE BEEN SEPARATELY PERFORMED OVER PAST YEARS (SEE BUFFINGTON ET AL. 2009; PROC. OF SPIE 7438 74380O-1) A FULL FLIGHT MODEL OF THE INSTRUMENT HAS NOT BEFORE BEEN ASSEMBLED AND TESTED. THE PERFORMANCE OF THE OPTICAL SYSTEM AS A WHOLE REQUIRES CAREFUL ATTENTION TO DETAILS OF HOW THE MIRROR LENS SYSTEM BAFFLE AND CAMERA ARE COMBINED. ALTHOUGH THIS SYSTEM'S STRAY LIGHT PERFORMANCE WHEN ILLUMINATED BY SPACECRAFT APPENDAGES AND OTHER SOURCES OF EXTERIOR LIGHTING SUCH AS EARTHSHINE AND MOONLIGHT HAS BEEN MODELED A FULL-UP SYSTEM PERFORMANCE NEEDS TO BE VERIFIED. LIGHT FILTERS AND POLARIZERS WILL ALSO BE TESTED SO THE INSTRUMENT CAN MEASURE POLARIZED THOMSON-SCATTERED LIGHT. THE SYSTEM WILL BE APPROPRIATELY TESTED ON THE GROUND AT NIGHT FOR LIGHT THROUGHPUT AND BRIGHT STAR SATURATION AND IN THE LABORATORY TO TEST ITS VIBRATION TOLERANCE AND THERMAL PROPERTIES. THIS APPROPRIATE COMBINATION OF TESTS WHEN SUCCESSFULLY COMPLETE WILL RAISE ASHI'S TECHNOLOGY READINESS LEVEL (TRL). THE FULL-UP SYSTEM WILL BE BUILT AND SUBCONTRACTED PRIMARILY IN HOUSE BUT WITH SOME DESIGN AND HARDWARE IMPLEMENTATION COMING FROM OUR UK COLLEAGUES AT THE RUTHERFORD APPLETON LABORATORY.DUE TO THE BACKGROUND ATMOSPHERIC BRIGHTNESS THE ASHI INSTRUMENT ON THE GROUND HAS INSUFFICIENT SENSITIVITY TO VIEW HELIOSPHERIC STRUCTURES FAR FROM THE SUN. IT IS TOO LARGE TO TEST ITS FULL-SKY HELIOSPHERIC CAPABILITY EFFECTIVELY ON A CUBESAT. WE THUS PROPOSE TO MAKE THIS FULL-UP SYSTEM FOR IN-SPACE USE ON EITHER A FUTURE LCAS INITIATIVE THAT WILL TEST ITS SPACE APPLICABILITY TO VIEW FAINT AURORA FROM A ROCKET LAUNCH OR ON A LOW EARTH ORBITER MINI-SAT IN AN EQUATORIAL OR HIGH SUN-SYNCHRONOUS ORBIT AND THEN ULTIMATELY ON A MISSION TO DEEP SPACE