422 Dozens of tests were carried out on the burner circuit in the presence of air and at room temperature, and  the result was always the same: the resistance bu rned the 0.25-mm nylon thr ead in roughly 2 seconds.  Tests were also carried out in a climate chamber to simulate the temperature variations experienced in orbit, and the mechanism has shown the same efficacy  as at room temperature, having worked at both  the minimum and the maximum temperature. 

Panel Deployment Mechanism (PDM)  CubeSat missions run into the problem of obtaining more power but having little space allowable to locate  solar cells. So starts the look for more power, a nd to achieve that, more solar panels are needed, and  thus small deployment systems. The design of a solar panel deployment mechanism for Xatcobeo is  mainly based upon the following goals:  • To ensure a packed maximum envelope of 6.5 mm from the structure in stowed configuration.  • To allow an easy integration in the structure of  Xatcobeo. It is intended to pack with the lateral  shear panel of Xatcobeo to integrate it as a single unit.  • To minimize mass of deployable parts.  The toughest requirement for solar array deployment in  Xatcobeo mission is the necessity to fit all the  system in an envelope of 6.5 mm from lateral plate of satellite to  avoid interference with the satellite  deployer. With this limitation it is possible to fit:  • One lateral aluminum shear panel, one board fixed to that panel holding solar cells, and one  movable panel with cells in both faces over a 1.6-mm board.  • One lateral aluminum shear panel, one board fixed to that panel holding solar cells, and two  movable panels with cells in both faces over 0.8-mm boards.  Both options have been used in Xatcobeo PDM design.   Solar Array Deployment for Xatcobeo  PDM is a mechanism consisting of two sets of deployable solar panels. In the first one, only one panel is deployed (PDM1) and the second is a double unfolding (PDM2).  Both share the first deployment system, and in the double an extra mechanism is added to allow the unfolding of an extra panel. Due to mass restrictions (to allow higher life span to this satellite mission is  necessary to give extra protection against radiation environment and increase the lateral shielding plates) the double deployment system is only used to validate the mechanism concept and instead of boards with solar arrays, two aluminum frames are used.  The primary mechanism (Figure 11 and Figure 12), invo lves a two-spring system in one axis with a travel  limit. The deployable board is fixed to an aluminum hinge by three bolts. This hinge is mounted in the lateral shear plate of stru cture of Xatcobeo by a system composed  by two lugs and shaft. The lugs are  mechanized in an enlarged area of that aluminum  shear panel. At both ends of the shaft, two steel  springs are located. Those springs are the actuator s of the rotation movement. There are two mechanical  limits (physically stops the opening rotation); first one fixed to the shear plate ensuring the correct maximum angle during deployment (90º), second one is a steel flat spring which fixes the panel in the final position reducing vibration problems (the rotating shaft has a slot on its end, during the rotation the  folded part of the spring slips over the shaft till it matches with the slot and the movement stops).  NASA/CP-2010-216272