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This paper presents a simplified orbit analysis program developed to calculate orbital parameters for the thermal analysis of spacecraft and space-flight instruments. The program calculates orbit data for inclined and sunsynchronous earth orbits. Traditional orbit analyses require extensive knowledge of orbital mechanics to produce a simplified set of data for thermal engineers. This program was created to perform orbital analyses with minimal input and provides the necessary output for thermal analysis codes. Engineers will find the program to be a valuable analysis tool for fast and simple orbit calculations. A description of the program inputs and outputs is included. An overview of orbital mechanics for inclined and Sun-synchronous orbits is also presented. Finally, several sample cases are presented to illustrate the thermal analysis applications of the program.

This paper describes the thermal design and analysis of the Clouds and the Earth's Radiant Energy System (CERES) instrument with emphasis on the detector thermal design. CERES has been selected as a payload on the Earth Observing System (EOS-AM-1) spacecraft which is the principle component of NASA's Mission to Planet Earth. Several broadband scanning radiometers will measure emitted and reflected energy from the surface of the Earth and the atmosphere to provide a long-term consistent database of the Earth's radiation balance and ultimately the effect of clouds on the Earth's climate. CERES requires precise active thermal control of the thermistor bolometer detectors to measure extremely small temperature changes induced by incident radiation. A detailed thermal design and analysis of the CERES detectors was completed to ensure minimal thermal disturbances from environmental heating and instrument temperature variations.

This paper describes the analysis and performance testing of a uniquely designed external heat exchanger. The heat exchanger is attached externally to an aircraft and is used to cool a laser system within the fuselage. Estimates showed insufficient cooling capacity with a conventional staggered tube array in the limited space available. Thus, a non-conventional design was developed with larger tube and fin area exposed to the ram air to increase the heat transfer performance. The basic design consists of 28 circular finned aluminum tubes arranged in two parallel banks. Wind tunnel tests were performed to simulate air and liquid flight conditions for the non-conventional parallel bank arrangement and the conventional staggered tube arrangement. Performance comparisons of each of the two designs are presented. Test results are used in a computer model of the heat exchanger to predict the operating performance for the entire flight profile.

A method for thermally analyzing convectively cooled flight experiments is presented in this paper. A three-dimensional fluid flow analysis code was used to optimize air circulation patterns and predict air velocities in thermally critical areas. A comparison between a fan flow analysis using this code and the performance characteristics of a typical isothermal free jet was made. The velocity profiles and radial distribution agree well for downstream mixing of the flow. Predicted air velocities from the fluid analysis were used to calculate forced convection coefficients for the flight experiment. These convection coefficients were used in a finite difference thermal analysis code to describe the response of air temperature and heat loss for the LIDAR Atmospheric Sensing Experiment (LASE) during transient flight profiles. The performance of the existing thermal design is described and the analytical techniques used to arrive at this design are presented.