For thermal mathematical models, the heat sources of nodes representing payload elements are usually modelled in the form of time-dependent bivariate input data arrays. Each node night represent an experiment or a package consisting of a number of small experiments, which can be lumped together considering location, thermal mass, heat rejection mode, thermal dissipation timeline and anticipated temperature levels.
The electrical power consumption of the individual experiments is usually given in the form of an electrical power timeline indicating identification, switch times and power levels provided by the planning authorities.
The electrical energy consumption of the equipment, however, is converted to a certain degree into thermal dissipation to be rejected to the environment at a certain rate and time.
For thermal modelling and analysis purposes, the individual power levels of small units must therefore be combined and modified with time lag factors and conversion coefficients to yield the lumped equipment load profiles for individual experiments or groups thereof. Based on the lumped power profile, the time slices with worst case conditions (e.g. max. load, min. heat rejection resources, etc.) can be identified from the mission power timeline for thermal analyses of individual payload elements or the total system.
For the time consuming task of dissipation profile generation, the interface software SETIS was developed in support of the D-2 S/L mission thermal system analysis to read timeline data from a data file, to screen, select and combine power profiles of equipment and provide interface data for graphical output of dissipation profiles and the associated bivariate data arrays in SINDA format.