Heat pipes efficiency for space thermal engineering is widely recognized and illustrated. Among majority of heat transfer tasks the heat pipe employment for high precision optical devices' thermal control is interesting and challenging. The main heat pipe functions are associated with a) heat removal tasks in the wide temperature range (90 ÷ 300 K), b) heat transfer and redistribution inside/outside of system, c) providing of isothermality of mounting plate (seats) of devices; d) regulating of temperature in selected device or group of devices. The brief description of technical realization example of heat pipe application in peculiarities of small satellite design is subject of this report.Heat pipe assignment in thermal design of BIRD' small satellite program is discussed as illustration of heat pipe implementation in design of mounting plate with sizes 0.5 × 0.5 m for group of optical devices which require dimension stability of optical systems in the temperature range −20 ÷ +50 °C. Main heat pipe qualification tests sequence is presented as well. They include: full performance testing - definition of thermal resistance of heat pipes, maximum heat transfer ability over exploitation temperature range, temperature distribution over the length of heat pipe; start-up capability, priming test; long-life/aging tests, thermal cycling/thermal shocks.One of discussed questions is choice of thermal sensors' locations at heat pipe tests and the analysis of influence of external associated units on formation of boundary condition in thermal interfaces.