With the trip coming up in less than a week, we’ve finalized our designs for the diagnostics that we are bringing on the trip and are just finishing up the assembly. One of our core missions is to deploy a grid of allsky cameras with the aim of gathering enough information to make a 3D reconstruction of auroral structure over the course of a night (similar to how stereographic imaging works!). Each unit now has a standardized structure, pulling elements from the designs that were put together by high school students under the Nord Anglia program. Below we give a breakdown of the design and some comments on students’ designs and where they came into play in the final version.
First, a reminder regarding some of our design constraints:
- Temperature: The unit must last for ~3 days at approximately -20 degrees Fahrenheit
- Internal support: The unit must provide support for the internal electronics (keeping in mind that it has to be able to survive shipping, handling during the trip, and/or the occasional fumble by a teammate 😊 )
- Visibility: The unit must be visible from a far distance in the dark (with a flashlight)
- Size: The unit must have an outer diameter of no more than 6 inches
A lot of the designs put forward by the Nord Anglia teams did an excellent job of hitting these constraints. We’ve done our best to pull from all of the designs what they did best!
Breaking it down by design constraint:
- Temperature: Groups made use of several types of insulation, including different forms of foam, a type of bubble wrap, and mylar reflective material. The first two are excellent at blocking conduction, while the latter is most effective at blocking radiative heat loss. We’ve incorporated all of these into the final design. The gap between the inner and outer PVC tubes is filled with foam. The outside of the camera is protected by a layer of reflective insulation, the support for which is a bubble wrap material.
- Internal support: Several groups designed structures that would provide a rigid internal support structure for the electronics. Teams on the build day made use of 3D printed parts and laser cut wood structures. We’ve opted to go for laser-cut MDF, a hardy and cheap option for building a large number of cameras. In our early tests of some of the designs we found that both for ease of use and for the greatest protection of the electronics, it was important for the internal structure to be coupled to the top plate of the unit (where the camera is mounted). This way all of the internals can be removed without straining any of the internal cables. One key function of the internal support is to protect against the different components harming each other as the unit is moved around. The battery in particular is heavy enough to seriously damage other electronics if it were to come loose. With this in mind, we appreciated designs that established multiple compartments for components within the camera. While we want the components to be protected, we also need them to be accessible.
- Visibility: We’ve emulated the groups that chose to put a full shiny outer layer on the camera units, making them very visible from the outside. We’ve recreated the logos on the outside to identify them each as well!
- Size: We’ve focused on keeping the insulation internal for the most part, with the exception of the reflective outer layer. This makes them easier to ship out to Alaska and handle while there.
Check out a schematic of the design below! Thanks everyone who helped us work through the design process!!!
