Vulnerability of spacecraft electric equipment to hypervelocity impacts

Paper number

IAC-05-B6.4.02

Author

Mr. Robin Putzar, Fraunhofer-Institute for High-Speed Dynamics, Germany

Coauthor

Dr. Frank K. Schaefer, Fraunhofer, Institute for High-Speed Dynamics, Germany

Coauthor

Dr. Hedley Stokes, United Kingdom

Coauthor

Mr. Richard Chant, Qinetiq Ltd., United Kingdom

Coauthor

Mr. Michel Lambert, European Space Agency (ESA)/ESTEC, The Netherlands

Year

2005

Abstract

To investigate the vulnerability of spacecraft (S/C) equipment to space debris and meteoroid impacts, hypervelocity impact (HVI) tests are performed on NiCd battery cells, electronics boxes and harnesses, arranged in representative S/C configurations. The tests are part of an ongoing ESA contract. Four HVI tests have been performed on battery cells, 25 on electronics boxes and ten on harnesses with planned impact velocities ranging from 6~km/s to 8~km/s. Projectiles are aluminium spheres with diameters ranging from 1.5~mm to 5~mm. This paper reports on the observed failure modes and impact conditions leading to failure of the equipment currently under investigation. The results of the test campaign are presented and the findings are compared to previously published damage equations.

The battery cells are single space-qualified NiCd prismatic cells. They are tested behind an Al honeycomb (H/C) sandwich panel (SP). Two configurations with different spacing between battery cells and H/C SP are investigated.

The electronics boxes are Al boxes with varied casing thicknesses. The boxes basically contain a field programmable gate array (FPGA) and random access memory on a printed circuit board. The FPGA is programmed to perform simple operations: counting and read~/ write memory access. The electronics boxes are tested in five configurations: three configurations behind an Al H/C SP, and two configurations behind multi-layer insulation (MLI). The different set-ups vary in spacing between electronics boxes and H/C SP or MLI respectively.

The harnesses consist of three different types of space-qualified cables: power cable, data cable and coaxial cable. The harnesses are tested in different configurations: behind MLI, and behind an Al H/C SP.

All tests are performed while the equipment is in operation: The batteries are discharged at 0.1~C rate (4~A). The FPGA inside the electronics boxes are operating. The harness cables are connected to a 40~V power source, a data signal source and a fixed 9.35~GHz source.  During HVI, all signals are monitored to determine type and severity of the perturbation induced on the equipment's operation.

Abstract document

IAC-05-B6.4.02.pdf

Manuscript document

IAC-05-B6.4.02.pdf (🔒 authorized access only).

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