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+=====  Project Description  =====
+In order to simulate the conditions of high altitude flight we must either buy or build our own thermal-vac chamber. Since commercial ones cost more than $10k, we will be designing, and building our own low cost thermal-vac chamber.
+=====  Design  =====
+====  Concept Overview  ====
+----
+**Step 1**
+{{:concept_1.jpg}}
+  * Place electronic parts into the chamber, minimize thermal conduction (possibly hang parts with fishing strings)
+  * Close the chamber
+  * Purge the chamber with dry nitrogen, allow air inside to exit
+  * Allow the chamber to consist of mostly dry nitrogen
+**Step 2**
+{{:concept_2.jpg}}
+  * Close off all values to the chamber
+  * Place dry ice around the chamber to cool the dry nitrogen and electronic parts through thermal convection
+  * Measure temperature inside the chamber and the temperature of the electronic parts
+  * Allow it to achieve -60C
+**Step 3**
+{{:concept_3.jpg}}
+  * Open the value leading to the refrigerator pump
+  * Pump the -60C dry nitrogen until the pressure is at 1010 Pa (pascals)  or 0.01atm (1% of pressure at sea level)  (estimate pressure at 100,000ft)
+  * The chamber is now simulating the environment of 100,000 ft  (-60C and 1010 Pa)
+====  Mechanical Overview  ====
+----
+The Thermal Vacuum Chamber concept consists of single 1/4" thick aluminum tube with a 7.5" ID and 8.0" OD. We then place a 1/4" aluminum plate on one end and 1/2" acrylic on the other end. We will also add a hole on the bottom aluminum plate to allow wires to pass. All joints are sealed with low temperature liquid gasket.
+Tubes available here: [[https://www.speedymetals.com/pc-4661-8371-8-od-x-250-wall-tube-6061-t6-aluminum.aspx|https://www.speedymetals.com/pc-4661-8371-8-od-x-250-wall-tube-6061-t6-aluminum.aspx]]
+Conceptual drawings of the environmental test chamber:
+{{:assm cyl.png?800}}
+====  Mechanical Stress Analysis  ====
+----
+The following is a stress analysis of one of the walls. It's fixed by the corners and a 14psi pressure load is applied to the wall (at room temperature). Results conclude that deflection is minimal, however more materials should be looked into.
+**Full analysis report:**
+Cylinder:  {{:cylinder-simulationxpress study-1.docx}}
+Bottom Plate:  {{:bottom-simulationxpress study-1.docx}}
+{{:displacement cylinder.png?800}}
+=====  Electronics  =====
+  * 6 Low Temperature Thermocouples
+  * Pump Controller
+  * Pressure Sensor
+=====  Software  =====
+  * None