This section presents the thermal specifications relative to Firebird’s Payload systems. These specifications are generally applicable to the initial Geo-transfer orbit and elliptical orbit phase of the mission. It is recognized that the re-entry portion of the mission will exceed these specifications as it burns up in the atmosphere.
 

1. General Electronics

In general for the electronic sub-systems, with the exception of sub-systems described specifically, rely on temperature range specifications of -25° C to + 50° C. This temperature range is used since this is a sub-set within a typial standard electronics temperature range.
 

2. Spectrometers

There are three spectrometers aboard Firebird, the Vacuum Ultra Violet spectrometer (VUV), the Ultra Violet spectrometer (UV), and the Mass spectrometer. The detectors on these spectrometers are sensitive to ambient temperature (background noise concerns) and are limited in the maximum upper temperature, thus, it is desired to both minimize the temperature excursion of the spectrometer over an orbit and to minimize the maximum operating temperature of the detector. The following temperature specifications apply for the spectrometers as a whole:

It should be noted that the A/D converters and the Logic devices could be mounted away from the forward bulkhead. The Detectors however are mounted forward near the center of the dome.
 

1. Optical Coefficients

To understand the data upon analysis, errors in the beginning of life optical coefficients (a ,e ) shall be taken into account along with expected degradation of the optical coefficients due to atomic oxygen and aerodynamic heating effects.