Mars Supplies Calculator

Every mission plan eventually collides with the same arithmetic: people consume mass, mass has to be launched, and launching mass is the expensive part. Talking about it in the abstract makes it sound solvable. Putting real numbers in a spreadsheet and turning the dials makes the shape of the problem obvious in about thirty seconds.

That’s what this is. Set the crew size, set the mission duration, adjust the per-person consumption assumptions, and the model tells you what has to go on the rocket.

Why it’s a spreadsheet and not an app

Because a spreadsheet is the right tool. Anyone can open it, everyone can see every assumption, and if you disagree with one of my numbers you can change it in the cell rather than filing an issue. Nothing is hidden behind code.

That transparency is the point. The output of a supply model is entirely a function of its inputs, and a model that hides its inputs is just an opinion with decimal places.

What it’s for

It’s the companion to the life-support material on the channel. When an episode says “closing the loop matters,” this is where you go to see by how much — because the difference between recycling eighty percent of your water and ninety-five percent is not a rounding error, it’s whether the mission fits on the vehicle.

Check this description against what the calculator actually models before launch, and add the Google Sheet link as the link: field so people can open it without going through GitHub.