My Space Balloon Project!!
I'm a 13 year old making a project I call "Project Blue Sandwich". It involves launching a high altitude weather balloon to carry a payload (the Blue Sandwich) to 80,000+ feet to capture images and video of the Earth and its curvature, along with a photo of a Lego lab inside the payload.
Payload Structure
The payload uses a compression based hull to make sure that it can withstand violent shaking during the balloon burst. The chassis is a cylinder made from a blue translucent 2L soda bottle sandwiched between two 1 inch XPS foam endcaps, hence the name Blue Sandwich.
At the top end cap will be all of the computers. At the bottom endcap, the battery and further insulation will be buried deep inside the foam.
Three nylon threaded rods and nuts will be used to squish both endcaps and the soda bottle "window" (both ends are cut off of the bottle), which creates an extremely strong frame.
The Lego lab (minifigures on a small baseplate with tables and levers and cool hinging things) will be suspended in the middle of the payload with fishing line.
There will be a pinhole pressure vent that is poked in the foam to allow air to escape, avoiding explosion as changes in pressure occur.
Onboard Systems and Managing
Three electronic components will be inside of the payload; A GoPro Hero 5 for external video recording of the Earth with the internal battery removed to reduce weight and avoid "Battery Cold" errors; a XIAO ESP32S3 Sense to take photos and videos of inside the payload; and a Lilygo T-Beam for GPS, altitude, and speed monitoring.
The XIAO Sense camera's lens will have to be modified for the project to work. It will be twisted counter-clockwise to change the focusing distance of the camera from infinity focus to be macro to focus on the Lego lab.
To prevent frost on the window at -60F, the inside of the bottle will be coated with a thin layer of dish soap or shaving cream, and the payload will have multiple silica gel packets inside to reduce moisture.
Power and Thermal Management
A 10,000 mAh power bank will be at the bottom endcap of the payload with USB cables connected to power all onboard computing.
As mentioned previously, the GoPro's internal battery will be removed to save weight and prevent cold battery errors. It will run on external battery from the power bank.
The power bank will be wrapped in chemical hand warmers and be buried deep in the foam to prevent cold temperatures, preventing the battery from shutting down.
The XIAO and T-Beam do not require extra warmers, as they generate enough heat to be able to function by themselves.
Budget and Logistics
The estimated total cost is $365.
A "Sponsor Sticker" plan will be used, where people can pay or donate to the project to have their name be printed out and stuck to the window inside of the payload, where images will be captured by the XIAO.
A 36-inch Spherachute will be attached to the 550g payload to ensure a safe landing back to earth. The parachute will launch by air flowing up onto the payload after the balloon bursts, making the parachute catch air. Once the balloon has landed, the Meshtatic capabilities of the T-Beam will be utilized to find the exact coordinates of the payload.
The most I've done so far is write this, plan with AI, and build the little Lego lab. If you have ANY ideas or suggestions, I would be happy to take them and improve my project. Thank you!