Satellites in orbit are at risk from collisions from more than 20,000 trackable micro-meteoroid and orbital debris (MMOD) as well as hundreds of thousands of particles too small to be catalogued, all of which can cause major to catastrophic damage to satellites. While mission planning takes into account catalogued MMOD, the vast majority of un-trackable debris still poses a major risk. Today, satellites employ Whipple shields to protect against smaller MMOD. Drawing from NASA’s Stardust mission, where particles travelling at hypervelocity were captured using aerogels of varying densities, the authors looked to research the effectiveness of aerogels as a material to augment existing shielding technology as well as mitigating the Kessler syndrome by capturing smaller particles. Testing began at the Planetary Impact Lab at Johns Hopkins University Applied Physics Lab after acquiring different types of aerogels: silica aerogels with a density of 0.095 g/cm3 and polyimide aerogels, also known as airloys, with densities ranging from 0.1 – 0.55g/cm3. Testing was done to characterize the shielding properties of aerogels at lower velocities, around 300 m/s, and provide an initial proof of concept to determine if aerogels could protect against and capture particles. Results showed that for 6mm alumina pellets travelling at around 300 m/s, gradient airloys can be used in conjunction with Kevlar to protect against and capture projectiles. Testing also showed that airloys can survive multiple impacts, potentially improving robustness in future shielding designs. With the initial success, steps were taken to build a material model of polyimide aerogels and inform the designs for higher velocity testing. The Eulerian hydrocode package, CTH, was used to model the impact physics. The updated model was then used to test velocities in the range of 1 – 5 km/s. The Hypervelocity Facility for Impact Research Experiments (HyFire) at Johns Hopkins University was used to conduct impact tests at 5 km/s. Three tests were conducted and it was found that even without Kevlar, a 1.5 cm thick airloy tile with a density of 0.55 g/cm3 completely stops a 3 mm aluminum pellet travelling at 5.1 km/s. At these velocities capture was not quantified due to the disintegration of the pellet. These test results have also been used to further mature the material model in CTH. Initial tests indicate that airloys may be designed to protect against particles travelling at velocities greater than 5 km/s. Whipple shields employ aluminum bumpers followed by multiple layers of Kevlar and Nextel epoxied together. Between the bumper and each Kevlar/Nextel layer, there is a standoff distance which increases the overall volume of the shield. By adding airloy layers, the standoff distance could be reduced by allowing the airloys to capture smaller particles from the bumper fragmentation, and absorb the energy of larger particles for subsequent capture by the Kevlar/Nextel mesh. Excess Kevlar and Nextel can then be removed, reducing weight. Future work is planned to determine specific characteristics needed in the airloys, with the goal of providing similar, if not enhanced, protection for reduced volume and overall weight.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Hypervelocity Impact Properties of Polyimide Aerogels for Space Debris Shielding and Capture


    Contributors:


    Publication date :

    2024-03-02


    Size :

    16934296 byte




    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English



    SIMULATION OF HYPERVELOCITY DEBRIS IMPACT AND SPACECRAFT SHIELDING PERFORMANCE

    Lukyanov, A. A. / Reveles, J. R. / Vignjevic, R. et al. | British Library Conference Proceedings | 2005


    Hypervelocity space debris testing

    Roybal, Robert / Tlomak, Pawel | AIAA | 1997


    Numerical Simulation of Hypervelocity Space Debris Impact

    Erzincanli, Belkis / Eken, Ali / Eken, Seher | IEEE | 2023


    Development of Improved Aerogels for Spacecraft Hypervelocity Capture

    Lisse, C.M. / Cheng, A.F. / Chabot, N.L. et al. | British Library Conference Proceedings | 2008


    POSS-polyimide nanocomposite films: Simulated hypervelocity space debris and atomic oxygen effects

    Verker, R. / Grossman, E. / Gouzman, I. et al. | Tema Archive | 2008