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- CADed a chassis for the payload
- 7.5x7x8' Cube-ish
- 2 layers split by a divider plate
- Balloon's 4 point harness attached to base plate, no top plate. Initially planned on mounting to a roof fixture, but changed to floor fixture because: a) it'd be redundant to have both a roof for the chassis and a roof of foam, and b) it'd make it hard to move things around and physically insert things with a roof in the way.
- Foam was made out of insulation foam board, selected at 3/4" to protect the sensors.
- 3/4" was chosen based on this guide for styrofoam: High Altitude Ballooning, From The Ground Up (and back again) – Dave Akerman
Improvements to be made
- Fix up timing next time and make sure to properly train everyone in CADing so a last minute grind doesn't need to be done again, and so that we have time to test, and play around with the physical model prior to launch
- Get a better visual idea of how to budget space (i.e. allocating better clearance)
- Account for battery drain during setup
- Determine heat emitted of active components
- Important Factors
- Dedicating enough space and surface area for all components. This determined the size of the cube and how many layers
- The size of the biggest components, including the spectrometer and the muon detector; primary determiners in layout and setup
- Weight - comply with regulations, minimize the size of spectrometer as it was being designed and built. We considered changing the
- Weight distribution - minimize spin as HAB ascended
- Screw embedment length - impacted our decision for wall thickness
- Thermodynamic regulation - foam was used to insulate the payload from high altitude temperatures. We concluded thermal emission from batteries weren't a problem.
- NOTE for later - Why were the batteries' thermal emissions not a problem anymore
- Sensor Accessibility - some components needed to have access to the outside. The Go-Pro was integrated completely outside of the box. The spectrometer was part inside so sensitive electronics could be safe, and we led a fiber optic cable to the outside of the chassis by cutting a tiny hole in the foam.
- Other Ideas
- Solid wall box
- 3 Layers
- Cut Foam for temperature insulation
- Everything was measured precisely and cut out in accordance
HAB Chassis Design Report
Task: Design a chassis for a high-altitude balloon test. The design must protect the interior components from temperature fluctuations and environmental exposure. Some sensors had their own individual requirements when implemented in the chassis:
- The spectrometer's sensor must be exposed through one of the sides of the chassis, pointing upwards exposed to the sun.
- The Go-Pro must be secured on the outside of the chassis, pointed to the horizon.
- The second live camera must be exposed through one of the sides, pointing just under the horizon.
Additionally, the chassis must not exceed a total weight of 6 lbs (excluding the balloon) due to §101.1(a)(4)(ii) (Hard Limit 6 lbs/package - Hard per-package weight cap)