Accession Number:



Keeping COMMx Cool: Design and Analysis of the Thermal Control System for the TacSat-4 Spacecraft COMMx Payload

Descriptive Note:

Corporate Author:

Report Date:


Pagination or Media Count:



The thermal requirements for the TacSat-4 payload electronics COMMx were difficult to meet with traditional methods of spacecraft thermal design. TacSat-4 is a U.S. Navy satellite intended to be launched into an elliptical orbit to provide relevant capabilities for communications, data exfiltration, and tracking. In a conventional passive thermal design, the electronics boxes are distributed around the spacecraft at suitable locations where heat rejection to space is available. This technique, while simple, can be inefficient with satellite real estate and so posed a real threat to COMMx payload implementation. Specifically, the spacecraft would become large and heavy due to inefficient packaging, requiring a larger and more expensive launch vehicle. The result of a trade study indicated that a Central Thermal Bus design, a concept first proposed by the U.S. Naval Research Laboratory in 1994 and the subject of a funded study in 1999, would yield the most efficient thermal control system for the TacSat-4 payload in terms of performance, ease of integration, and more importantly, massvolume. The challenge facing NRL thermal engineers was to design the payload thermal control system to fit within the multitude of program constraints without limiting payload performance or mission goals.

Subject Categories:

  • Unmanned Spacecraft

Distribution Statement: