Non-Pyrotechnic Multi-Point Release Mechanisms for Spacecraft Release  Ambrosio Mejia*, John Sudick* and Geoff Kaczynski*  Abstract  The Non-Explosive Actuator (NEA) is an electrically initiated Hold-Down Release Mechanism (HDRM) that  has the ability to carry a very high tensile preload until commanded to release, with the additional advantage  of very low output shock. The NEA has been used for many different spacecraft hold-down applications  over the years, but has had limited use as a payload release mechanism due to the limited data regarding  its simultaneity capability. The objective of this paper is to expand on this simultaneity database by  describing and summarizing Phase I of the NEA Multi-Point Separation Testing that shows that the variation  in NEA actuation time can meet certain simultaneity requirements necessary for spacecraft payload  separation. The data collected shows NEA’s can meet simultaneity requirements of less than  5 ms.  Introduction  NEA Electronics manufactures both pyrotechnic and non-pyrotechnic release mechanisms. NEA  Electronics was recently involved in several opportunities that required the release of multiple spacecraft  using the multi-point hold down method. All the opportunities pursued elected to use our pyrotechnic  separation nuts instead of our low-shock Non-Explosive Actuator (NEA). At the time, the reason stated by  potential users for selecting the pyrotechnic device technology over the NEA centered on concerns with the  lack of simultaneity data between multiple NEA’s used in a time-critical application.  Pyrotechnic devices have been widely used for payload separation in the past, but with the increased need  for low-shock mechanisms, especially with smaller constellation payloads, this simultaneity data for NEA  release mechanisms will prove very useful to the aerospace mechanism community for alternative lowshock design solutions. This paper is an expansion of the data collected and presented in a poster  presentation for ESMATS 2017.  Background  Before diving into the testing, it is best to understand the basics of the NEA design, as well as the details  of what constitutes NEA actuation time, including the primary factors that affect the actuation time.   The NEA HDRM is an electrically initiated, one-shot release mechanism that has the ability to carry a very  high tensile preload until commanded to release. The preload is applied through a release rod held in place  by two separable spool halves which are in turn held together by a tightly wound restraining wire. The  restraint wire is held in place by redundant electrical fuse wires; actuation of either circuit allows release,  assuring maximum reliability. When sufficient electrical current is applied, the restraint wire unwinds  allowing the spool halves to separate, releasing the release rod and the associated preload.  The NEA actuation time is the time from application of current to the start of the release rod exiting from  the NEA (i.e., preload drop to zero). This actuation time can be split into two (2) independent segments per  Figure 1.  *NEA Electronics, Moorpark, CA (subsidiary of Ensign-Bickford Aerospace and Defense) Proceedings of the 44th Aerospace Mechanisms Symposium, NASA Glenn Research Center, May 16-18, 2018 NASA/CP—2018-219887 247