Research progress of space non-pyrotechnic low-shock connection and separation technology(SNLT):A review

Space missions have become diversified in recent years, where connection and separation devices play a crucial role as key components of various spacecraft. Traditional pyrotechnic devices have the advantages of large carrying capacity, rapid motion and functional reliability. However,their shortcomings such as great release shock, poor safety, unrepeatability and other prominent defects make them unsuitable for new generation spacecraft such as microsatellites to separate at low shock or lock repeatedly, etc. Therefore, it is necessary to develop space non-pyrotechnic low-shock connection and separation devices(SNLD) which are required for advanced aerospace missions. In this paper, the progress of the research on space non-pyrotechnic low-shock connection and separation technology(SNLT) is summarized and reviewed. Proceed from the principle of reducing shock for non-pyrotechnic devices, present studies are classified from the perspective of actuating technology and systematic designing methods. For non-pyrotechnic actuating techniques,according to different driving sources, the separation devices are classified into several main categories: electric, magnetic, gas and thermal actuating devices. The actuation principle and application prospect of separation techniques are introduced and the working process, dimension and mechanical properties of typical devices are compared and evaluated. For the systematic designing method, the common mechanism types of SNLDs are summarized according to the designing concept of reducing shock. Then connection configurations are classified according to the structural forms of connection devices, of which the principles, bearing capacities and general applications are discussed. This paper systematically summarizes the key problems, puts forward the future development trend of SNLT, and points out the breakthrough direction for related scholars.

A reusable SMA actuated non-explosive lockrelease mechanism for space application

After the satellite is launched with the carrier rocket,it is necessary to separate the satellite from the rocket at an appropriate time to ensure that the satellite enters the intended orbit.In this process,it is vital to ensure a reliable connection and accurate separation.With the increasing use of microsatellite in orbit,the contradiction between the shock of separation and the requirement of the platform’s dynamic environment is becoming increasingly prominent.Therefore,the traditional pyrotechnic separation device can no longer meet the requirements.This paper presents a reusable non-explosive release actuator using shape memory alloy(SMA)wire for high load and low shock.The system is based on the Fast Acting Shock-less Separation Nut(FASSN)technology.Using the shape memory effect of SMA,a biased SMA wire trigger has been developed,which is used as the driver source of the actuator.At the moment of receiving the electrical signal,the SMA wire generates stress and deformation.The trigger set free the constraints on the mechanical components,and the target is released.Experimental results indicate that the trigger device can unlock successfully and well meet the technical objectives.