CubeSat appendices such as solar panels and antennas often need to be constrained by a release mechanism during launch. These appendices are then deployed once the desired orbit is reached. The usual constraint method used is a combination of an unpredictable/ unreliable fishing line and burning wire. If a proper release mechanism is used, it utilizes a considerable amount of CubeSat internal space, making the internal packaging of the satellite more difficult. These two methods have adverse effects on CubeSat performance.

The DANY mechanism provides a secure method to constrain these deployables without using any internal space due to its minimized thickness with dimensions of 1.250×2.875×0.188 in. (≈3.18×7.30×0.48 cm). DANY is fastened to the chassis and provides a secure interface for the items to be deployed. Two variations of the DANY mechanism exist with different interfaces for the deployable: threaded insert or pin puller. Both variations work the same way: two pins hold the deployable directly as a pin puller or hold a threaded block to provide a threaded interface. The two pins are preloaded with springs and held in place by a plastic piece. A printed circuit board that serves as a closeout panel contains a redundant set of wires to compromise the strength of the plastic piece by heating it. Once the strength is compromised, the springs will push the pins. The mechanism also contains a set of redundant switches to confirm proper operation of the release mechanism. Nominally, the mechanism utilizes 3 A current at 3.3 V for a total of 9.9 W for 0 to 4 s.

Several tests were conducted to characterize the mechanism such as thermal vacuum hot and cold deployments. The mechanism was tested to –20 °C and +55 °C. The mechanism is capable of withstanding 300 lb (≈1,334 N) of force while stowed and 3 lb (13.3 N) of force while being actuated. The mechanism can be refurbished/reset by replacing the plastic piece.

This work was done by Luis Santos Soto, Scott Hesh, and John Hudeck of NASA Wallops Flight Facility for Goddard Space Flight Center. GSC-16900-1


NASA Tech Briefs Magazine

This article first appeared in the May, 2015 issue of NASA Tech Briefs Magazine.

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