Experimental Investigation of the Vulnerability of Spacecraft Equipment

Consequently, measures to protect
spacecraft against space debris are being
investigated all over the world. Most of
the studies concentrate on reducing the
vulnerability of spacecraft by introducing
external shielding. These studies
ignore the intrinsic impact protection
capability of the equipment under consideration.
To overcome this shortcoming,
ESA funded work to investigate
the vulnerability of satellite equipment
to hypervelocity impacts and the corresponding
equipment failure modes (ESA
contract 16483, Michel Lambert). The
considered equipment was fuel and heat
pipes, pressure vessels, electronics
boxes, harness, and batteries. All equipment
was placed behind aluminium honeycomb
sandwich panels (Al H/C SP),
representing the typical satellite structure
wall. The impact experiments were
performed at Fraunhofer Institute for
High-Speed Dynamics - Ernst-Mach-
Institut - in Freiburg, Germany, under
the supervision of Robin Putzar, using
their powerful two-stage light gas gun
accelerators to simulate experimentally
hypervelocity impacts of Space Debris
particles in a laboratory environment.
Cooperating partners were QinetiQ of
Farnborough, UK (Hedley Stokes), and
OHB-System AG in Bremen (Rolf
Janovsky, Oliver Romberg). One novel
aspect of this project was that the equipment
was evaluated in its normal operating
mode, thus being highly representative
of actual spacecraft operation. In
the following sections, some results of
impact tests on operating harnesses and
computers placed behind typical satellite
structure walls are provided and discussed.