First for the 3D printed models, I modified one from Thingiverse [ISS Model - https://www.thingiverse.com/thing:992074] to fit the small baby solar panels I would later use and then designed some arms to hold it and a box to hold the electronics. Lastly, I wanted to use an Earth Globe from Thingiverse [Globe - https://www.thingiverse.com/thing:2565357] that was clear to 'light up' when the LED inside fired for ISS passage. Colors used were from the Apollo series (Black, White, Clear, and Grey).
The guts of this project used the Particle Photon circuit board, an Adafruit LED, 30 mA Solar Panels, a Lipo battery, and a charger. I decided to put the components on a breadboard then use jumper cables to connect everything. Small amounts of soldering to connect new wires to the solar panels and to connect them to the battery charger circuit. There is also a capacitor hooked up to the positive end of the solar panels. Under relative bright conditions the panels do charge the Lipo battery. I did incorporate a plugin hole for the cable to attach for the micro-usb port on the charger circuit to recharge the battery as it is required. The last added piece was a battery port with a switch to turn the circuit on and off.
With all the components assembled, the coding and API linking is the most arduous part of this project so far. The code is meant keep battery usage minimal. This circuit is supposed to wake up, check the next ISS passage time via the Open Notify ISS from input Latitude/Longitude, then sleep until its almost time. Then the beacon would wake, notify you via IFTTT, and blink LEDs before going back to sleep and repeating the cycle.
Thingiverse 3D Model Files:
Making the solar panels functional is an absolutely awesome detail, I appreciate you putting in that extra effort.