What do you mean? SpaceX didn't invent the reusable rocket, and my understanding is that Falcon 9 is still not significantly more economical than disposable rockets, and that the main reason it's attractive is that it's not Soyuz-2.

Your understanding is wrong; see page 2 of https://ntrs.nasa.gov/api/citations/20200001093/downloads/20.... That’s a log plot!

The backing table is on page 8. Falcon 9 is (was, in 2018! It’s only cheaper now.) at $2700/kg to LEO. No one else is below $4k, except… Falcon Heavy.

> SpaceX didn't invent the reusable rocket

There isn’t a single inventor and reusable rockets emerged through decades of research.

But: SpaceX was the first to make orbital-class reuse routine and economically viable.

I found that surprising, so I looked on Wikipedia.

Soyuz-2 capacity to LEO: 8,600KG

Falcon 9 capacity to LEO: 22,800KG when expended, 17,500KG when not.

Soyuz-2 Cost to Launch: $35 Million

New Falcon 9 Cost to Launch: $70 Million

Used Falcon 9 Cost to Launch: $50 Million (cost to SpaceX: ~$25 Million)

Soyuz-2 cost per KG: $4000 (data from 2018)

New Falcon 9 cost per KG: $964 when expended, $1250 when not.

Use Falcon 9 coster per KG to Customer: $893 when expended, $690 when not

So realistically, Falcon 9 is roughly 20-30% the price per KG when new, and dropping to a minimum of 17.25% of the price when used.

Plus you get a larger diameter payload fairing and the ability to launch a payload up to 4X the size.

I'm pretty sure that even used as an expendable rocket, 1/4 the price per KG (if you need the capacity) is a pretty significant improvement. Now I understand why satellite ride-shares are so popular!

Space is basically half the cost of it's competitors on a per kg basis. And while previous experiments like the DC-X existed, SpaceX absolutely gets credit for the first operational reusable rocket stage.

And I say that as someone that despises Elon and the way he casts his companies as due to his personal technical genius.