Development of a dust impact detector at low-mid velocity ranges for a rendezvous mission to small bodies
Abstract
Since the dawn of solar system exploration, cosmic dust measurement by spacecraft has been mainly focused on hypervelocity impacts in cruising phases, fast flybys to target bodies and incoming sporadic dust flux to orbits around planets/satellites. Recently mission opportunities are expanding to rendezvous to small bodies like comets and activated asteroids and other celestial bodies emitting local dust components such as icy plumes of Ceres, Europa, and Enceladus. In such rendezvous missions including Rosetta/Philae to a comet nucleus, spacecraft receives impacts by local dust at much lower velocities than the hypervelocity regime, i.e., well below 1 km/s order. In order to detect impact signals and to derive physical properties of these local dust grains, we must develop a new type of dust detector sensitive enough to lower momentum (i.e., smaller and slower impacting particles) than previous hypervelocity dust detectors. In this study, we started to develop such a new detector by redesigning electronics and data processing programs of the ALADDIN Poly-vinylidene Fluoride (PVDF) film sensor array onboard the solar sail spacecraft IKAROS launched in 2010. The IKAROS-ALADDIN was originally designed for detecting hypervelocity impact signals of as large meteoroids as 10 microns order during the interplanetary cruising between the Earth and Venus orbits. We first added an amplifier circuit just after the IKAROS/ALADDIN data processing unit and conducted single particle impact experiments of 10 to 50 micron glass beads, 20 micron aluminum particles, 30 micron iron particles, 100 micron alumina particles onto the IKAROS-type PVDF film sensors at low to medium velocity ranges, namely 1 to 600 m/s. With the 4 cm ^{2} effective area of the PVDF sensor, we obtained an empirical relationship between impact momentum and signal profiles. The second step of our development is to distinguish the amplified signals of lower momentum cases from integrated noise signals by reducing multiple noises generated from the sensors, the electronics, and the impact experiment apparatus and by re-arranging an array of amplifiers and noise filters for the data processing unit in order to allow the PVDF sensors to have larger effective areas like the IKAROS-ALADDIN.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E1565I