Actuators for deployable space antennas operating under temperatures around the liquid helium point (~4.2 K) are in great demand since the number of space missions involving deployable mirrors is growing. We are suggesting a design of actuators to provide adjustment of mirrors with the active surface control system having in view the Millimetron observatory (Spektr-M space mission).

Having defined the reference precision, power consumption, and resistance to vacuum and cryogenic temperatures of such actuators, we have analyzed probable solutions, and accordingly created our own cryogenic models based on a well-proven motor previously used for similar but non-cryogenic applications. We are suggesting that these models could be used as the developmental prototypes for batch production thus cutting possible costs.

The cryogenic tests of our developmental prototypes have been conducted both in the boiling liquid nitrogen medium and under closest to open space conditions in the cryogenic vacuum chamber with the Cryomech closed-cycle cryorefrigerator PT-407 cooled down to the liquid helium point. The original test setups which were a challenge in itself, test algorithms, and the test results are being presented. The properties and electrical characteristics, and results of the tests of the actuators’ thermal behavior when adjusting a deployable mirror in emulated real-life situations mimicking the conditions of the Millimetron observatory are being discussed.

由于涉及可展开反射镜的空间任务数量不断增加，因此在液氦点 (~4.2 K) 附近的温度下运行的可展开空间天线的致动器需求量很大。我们建议设计一种执行器，以便通过有源表面控制系统对反射镜进行调整，并考虑毫米波天文台（Spektr-M 太空任务）。

在定义了此类执行器的参考精度、功耗以及对真空和低温的耐受性后，我们分析了可能的解决方案，并相应地基于先前用于类似但非低温应用的经过充分验证的电机创建了我们自己的低温模型。我们建议这些模型可以用作批量生产的开发原型，从而降低可能的成本。

我们的开发原型的低温测试已在沸腾的液氮介质中以及在低温真空室中最接近开放空间的条件下进行，其中 Cryomech 封闭循环低温冰箱 PT-407 冷却到液氦点。原始测试设置本身就是一个挑战，测试算法和测试结果正在呈现。正在讨论在模拟毫米波天文台条件的模拟现实情况中调整可展开反射镜时执行器热行为的特性和电气特性以及测试结果。