David Senra

It's written by my friend Eric Jorgensen.

It'll be out in a few weeks.

So back to the essay, another subheading, rethink from first principle.

Start with the actual product.

If you accept existing solutions, you accept their cost structure.

So rebuild from physics instead.

Don't ask, what do rockets cost?

Ask, what should rockets cost?

Elon eventually named this the Idiot Index, the ratio of the actual cost of a part to the cost of its raw materials.

If the ratio is high, he says, you're an idiot.

Consider the Falcon 1 actuator.

A vendor quoted $120,000 in 18 months of development.

SpaceX's engineers built it for $3,900.

When founding engineer Tom Mueller's team asked about a critical engine valve, the supplier kind of smirked and left after hearing SpaceX's timeline and budget.

Mueller's team made the valve themselves.

This pattern repeated across the vehicle.

The Dragon's capsule docking mechanism was reinvented from off-the-shelf bike shocks and catalog parts instead of adopting NASA's existing design.

There are probably a hundred examples like this, most not discussed in public.

The philosophy extended to fundamental architecture, SpaceX uses one propellant pair, liquid oxygen and RP-1 kerosene, across all stages.

The vacuum Merlin engine uses a fixed nozzle extension instead of a deployable one,