a. Where analysis through computer modelling is part of the acceptance procedure, the analysis shall include the following effects:
1. primary electron and ion currents,
2. secondary emission,
3. photo-emission and back-scattered particle currents, and
4. conductivity.
b. An analysis shall be performed to assess the secondary yield characteristics during the operational life, to be used in the design for the overall charge control of the spacecraft.
c. A spacecraft design shall not be validated by simulation alone but by the continuity and control of surface materials described in clause 6.3.3.
NOTE This is due to unmonitored changes to material characteristics that can occur in flight.
d. The simulation and testing to be used as part of the validation procedure for non compliant materials and assembly to demonstrate the requirements on charging, shall be agreed with the customer.
e. If assessment of the electric fields and space charge density in a large volume is performed, the 3-D spacecraft charging codes to be used shall be defined.
NOTE These 3-D spacecraft charging codes can consider the detailed geometry of the spacecraft. Various charging codes with different complexity are available for performing the assessment (see Annex C).