442 Table 4. List of Materials  Mechanism Component Material Dimensions  Chassis Panel 7075 Aluminum Plate 1.27 mm (0.05 in)  Posts 6061 Aluminum Bar Stock 7.87 x 7.87 mm   Release Mechanism Panel 5052 Aluminum Plate 1.27 mm (0.05 in)  Deployment Panel Quasi-iso Carbon Fiber Plate 2mm plate  Scissor Arms Unidirectional Carbon Fiber Bar 1.47 x 4.50 mm  Locking Latch 304 Stainless Steel Shim Stock 0.254 mm (0.01in) Hinge Low Carbon Steel n/a 

Figure 10. Assembled Release Panel Cutter Strand   Metal film resistors and Dyneema wire are used in the design of the XSAS release cutter mechanism. ¼  watt 10 Ω resistors were chosen. With such a low power rating each resistor is designed to handle only  28 mA with a 9-V power source. Instead, because of t he low resistance, when the circuit is shorted, the  resistor draws 900 mA, more than 32 times the rated val ue. This overload heats the resistors in excess of  150°C, the melting point of Dyneema wire, in 1 second. Aside from the low melting temperature, Dyneema was chosen because of its superior tensile strength, which is 15 times that of steel §. This allows  the wire to be drawn tightly through the release panels while stowed, which has two benefits. First, it creates a snug and reliable fit between the panels and power bus; second, it produces a tight connection with the surface of the resistors.  To ensure and intensify this co nnection, the resistors are mounted  slightly below the level of the release panel mountin g points. Figures 9b and 10 display the positioning of  the resistors and threading of the Dyneema wire. 

The spring hinges are COTS components manufactured by Guden. To make each hinge compatible with  a locking latch, a 0.30-mm (0.012-in) jeweler’s saw wa s used to cut slots in the barrel of the hinge. The  locking latch is created from water- jet cut 0.254-mm (0.010-in) stainless steel shim stock. Multipurpose  stainless steel 304 was used because of its good formability properties and excellent corrosion resistance. The 0.0508-mm (0.002-in) excess tole rance on the slot ensured the latch tooth would  successfully fall into the slot on each test. Once th e latch is mated with the hinge, the entire system  requires only 3.1 mm of vertical space. As a result, 16 stacked panels require 95 mm satisfying the volume and power requirement.  The scissor components are completely constructe d from COTS materials and hardware. They were  discovered as a design necessity through early prototypes. As a result, the structure and joint needed to be integrated into the design late in the process.  To minimize its impact on the existing design the  structure needed to be isol ated to one side of XSAS. Unidirectional carbon fiber/epoxy rod, produced by a  hobby supplier, presented an ideal solution for the st ructure. The carbon scissor arms are joined together  and at the solar panels with stainless steel 2-56 mach ine screws and nuts. Brass washers are place in  between the hardware and carbon surfaces to minimi ze fatigue on the composite. The scissor joint                                                                § http://www.dsm.com/en_US/html/hpf/home_dyneema.htm  Dyneema  Wire  Release Panel  Mount   Resistor   NASA/CP-2010-216272