Design Verification of Whipple Bumper Shields for Protecting Small Spacecraft from Hypervelocity Impacts During Fast Fly-Bys to Dusty Objects

Abstract JAXA provides a 24U-class daughtership “B1” to ESA’s Comet Interceptor (CI) mission for fast flyby observation of a long-period comet or an interstellar object. The spacecraft must survive in the dusty environment with a lightweight impact bumper shield at an encountering velocity of up to 70 km/s, which is too fast to be reproduced by ground experimental facilities. We designed a three-layered Whipple bumper with hydrocode simulations that were confirmed to reproduce the successful survival of Giotto’s bumper shield for the Comet Halley flyby in 1986. The ballistic limit curve (BLC) calculations showed that the impact damage could be stopped on the second layer at the maximum mass and velocity for the mission with a maximum mass of 34 mg and maximum velocity of 70 km/s, based on the EDCM 4.1 dust model. Our hydrocode calculations were consistent with the protection performance of real-scale impact experiments at 1.0-6.5 km/s by employing Japanese AFRP as intermediate layers. This result will open a new era for fast flyby exploration of small spacecraft to dusty objects. This is a summary of the refereed paper of the same title in preparation for submission [1].