Build a satellite internet network

Your mission

Design, build and defend a model network for an island school, a mountain clinic or a ship. Encode a message and measure what reliability costs. Derive the speed your relay needs and calculate how long it stays in view. Close an energy budget across an eclipse. Then break your own design on purpose, measure what happens, and state precisely which claims your evidence supports.

This is an independent enrichment class with no grade-course prerequisites, but it is quantitative throughout. You will need ratio and percentage, substitution into a formula, and a calculator. The Run the numbers section in every lesson is split in two: the core tasks need arithmetic and rearrangement, and the deeper tasks assume Grade 9–12 tools — trigonometry, logarithms and a little Newtonian mechanics. Doing only the core tasks is a complete course.

Choose your course length

One 90-minute session each week. Eight weeks gives time to measure, calculate and redesign; four weeks keeps the same eight lessons and the same physics, with the quantitative work concentrated into fewer, longer blocks.

Eight lessons, one growing project

What you will learn

• Measure information in bits, and calculate what an error-detecting or error-correcting code costs in rate.
• Use c = fλ to place a channel on the electromagnetic spectrum, and explain why bandwidth and signal-to-noise set a hard ceiling on data rate.
• Derive orbital speed and period from gravity, and show that an orbit is free fall with enough sideways speed.
• Use the elevation-angle relation cos(ε + γ) = (R / r)·cos ε to calculate a satellite's footprint, pass duration and slant range.
• Close an energy budget across an eclipse using the solar constant, the cosine law and depth of discharge.
• Separate propagation delay, queuing delay and throughput, and predict when a vacuum laser relay beats a fibre route.
• Judge a design against a measurable target under a named failure condition, and state what the measurement cannot support.

Gather your materials

• Paper or graph paper, pencils, coloured markers and a ruler
• A scientific calculator, or a phone calculator with sin, cos and log₂
• A protractor and a length of non-stretch string
• Reused cardboard, tape and scissors
• A flashlight, a sheet of opaque card and a stopwatch
• 20 index cards, 8 counters and a notebook
• Optional: a rated educational solar-cell kit with a matching load, a multimeter and a lamp

The core class runs on paper, string and a calculator. The solar kit is optional and its lesson has a complete paper pathway. Use scissors with appropriate supervision, keep flashlights out of eyes, and use only correctly rated educational electronics.

How the class works

Each lesson opens with something to try, explains the physics, puts you through a build and a set of matched measurements, then asks you to run the numbers properly — core tasks first, deeper ones after. Every lesson also carries a worked example, a common mistake with its cause, an independent checkpoint and teacher notes. Keep a mission notebook: prediction → method → observations → calculation → evidence → revision.

Classroom models simplify the world, and every lesson says where its own model stops. A result from one is a bounded claim about the model, never a prediction of real service.