1. Resistivity measurements performed using the classical conductive electrode method obtained resistivity values of approximately 1E16 ohm-cm. After several months in vacuum, the same measurements were repeated and similar results were obtained.
2. In the second method, keV electrons in vacuum were applied directly to the exposed insulating surface of the samples. After injecting the electrons, the samples were then monitored for decay of the resulting surface voltage. The RC time constant of the decay indicated that the resistivity was greatly in excess of 6E18 ohm-cm. This method of measurement is more indicative of the charge leakage properties of the polyimides in space.
3. Two experimental apparatus were developed to generate and monitor surface voltages in the range 10 V to 10 kV. In one apparatus the voltage can be achieved by accumulating electrons that impact the surface with kinetic energies not exceeding 20 eV. The other apparatus causes electrons to impact the surface at greater than 2 keV. All measurements were performed on samples SI-001 and KA-001 provided by James Bockman and others of NASA Langley.

This work was performed at JPL under funding by NASA, RTOP 2.B.04.2.