My first AERO-LITE design was wrong. Not slightly wrong. Fundamentally wrong. And I did not realize it until I ran the numbers.
The Original Plan
I thought: cabin air goes in, compressor squeezes it, concentrated CO₂ comes out. Simple, right? One stage instead of four. Less complexity. Fewer parts.
I even started sketching the compressor placement in my 3D model. I was proud of how "elegant" it was.
The Math
Cabin air is roughly:
- 78% nitrogen
- 21% oxygen
- 0.04% CO₂ (can rise to 1,000+ ppm in a sealed habitat, but still ~0.1%)
- Trace gases
If I compress 100 liters of cabin air to feed the Sabatier reactor, 99% of the energy goes into compressing nitrogen and oxygen. Only ~0.1% of the molecules I am compressing are actually CO₂.
I stared at the calculation for a long time. Then I felt stupid. Then I felt excited — because I had found the real problem.
The Redesign
I threw out the single-stage design and built the four-stage system:
- Dry: Remove moisture (silica gel)
- Trap: Capture CO₂ selectively (zeolite 13X)
- Release: Heat to drive off concentrated CO₂
- Compress: Now you are only compressing CO₂, not 99% nitrogen
The insight: capture first, compress later. Concentrate the useful stuff before you spend energy moving it.
Why This Matters Beyond AERO-LITE
Every engineering decision is a trade-off. My original design traded simplicity for efficiency. The new design trades complexity for mass and power savings — which is the right trade when every pound to the Moon costs thousands.
I learned that the first idea is rarely the best idea. The best idea comes after you do the math, feel stupid, and fix it.