Uploaded December 2025 | Updated September 2026, 1 week ago
When we hear about space rockets, we already know one thing for sure: they are extremely hard to build.
But what most people don’t realize is this — the engine is by far the hardest and most expensive part of the entire rocket.
In many launch vehicles, the engines alone can account for up to 70 percent of the total cost.
Think about that for a moment.
If a rocket costs 100 million dollars, the engines alone can cost 70 million dollars.
And even after spending that much money, there is still a high chance the engine fails during development.
That’s exactly why many space companies avoid building engines altogether.
Instead, they buy engines from other companies that already went through years of failure, testing, and massive losses.
This is why United Launch Alliance buys engines.
This is why smaller launch companies rely on outside suppliers.
Building engines from scratch is risky, slow, and brutally expensive.
But SpaceX chose a completely different path.
When we hear about space rockets, we already know one thing for sure: they are extremely hard to build.
But what most people don’t realize is this — the engine is by far the hardest and most expensive part of the entire rocket.
In many launch vehicles, the engines alone can account for up to 70 percent of the total cost.
Think about that for a moment.
If a rocket costs 100 million dollars, the engines alone can cost 70 million dollars.
And even after spending that much money, there is still a high chance the engine fails during development.
That’s exactly why many space companies avoid building engines altogether.
Instead, they buy engines from other companies that already went through years of failure, testing, and massive losses.
This is why United Launch Alliance buys engines.
This is why smaller launch companies rely on outside suppliers.
Building engines from scratch is risky, slow, and brutally expensive.
But SpaceX chose a completely different path.
