Low vibration microminiature split Stirling cryogenic cooler for infrared aerospace applications

Abstract

The space-borne infrared instrumentation is known to be inherently susceptible to cryocooler induced vibration, the attenuation of which usually relies on active multi-tonal momentum cancellation under supervision of a dedicated controller. In this approach, the typical single-piston expander is actively counterbalanced by a motorized counterbalancer and the typical dual-piston compressor is counterbalanced by actively synchronizing the motion of the opposing moving piston assembly. The feedback signals are usually provided by external vibration sensors (force transducers or accelerometers). Although compliant with the most stringent space requirements, like 0.2N rms over the frequency range 0-1kHz, such a conservative vibration control approach can result in using outdated, oversized, overweight and overpriced cryogenic coolers for some applications. Such a "space heritage" practice becomes increasingly unacceptable for space agencies now operating within tough monetary and time constraints. The authors are advocating the purely passive approach to a vibration control relying on the combined principle of tuned dynamic absorber and low frequency vibration isolator having a potential to outperform the systems of active vibration cancellation with respect to overall system effectiveness. This approach warrants particularly strong consideration for cost-sensitive missions.

Performance evaluation of spaceborne cryocooler micro-vibration isolation system employing pseudoelastic SMA mesh washer

“…In space applications, spaceborne pulse-tube-type cryocoolers are widely used to cool down the focal plane of an infrared (IR) imaging sensor to low cryogenic temperatures, on account of their advantages of simplicity, low cost, and high reliability [2,3]. The major advantage of such cryocoolers in comparison with stirling-type coolers [4] is the absence of any moving part in the cold head, which results in a considerably longer mean time to failure (MTFF).…”

Performance Enhancement of Spaceborne Cooler Passive Launch and On-Orbit Vibration Isolation System

“…To meet the strict microvibration requirement for highresolution observation satellites, mounting an isolator is a solution, as this attenuates the transmitted microvibration to the microvibration sensitive payload. Passive vibration isolation systems, which are attractive vibration isolation methods, have the advantages of simplicity, robustness, and reliability [5][6][7][8][9][10][11][12]. Several types of passive vibration isolation systems were proposed in previous studies.…”

“…The effectiveness of this isolation system was investigated by incorporating an analytical model and performing an experiment. Veprik et al [8] proposed a vibration protection system for infrared applications employing a K527 split-Stirling linear cryogenic cooler manufactured by the RICOR company. This system consists of a stiffened and heavily damped vibration isolator with a tuned dynamic absorber using an Oxford-type flexural element to suppress the self-induced force by a large factor of 20 times at the driving frequency of the cooler.…”