Defense spending as a whole is north of $700 billion a year. But the Space launch market is obviously much smaller, but it is expected to increase at a pretty fast pace.

> The Global Space Launch Services Market size was estimated at USD 12.86 Billion in 2020 and expected to reach USD 14.92 Billion in 2021, at a Compound Annual Growth Rate (CAGR) 16.29% from 2020 to 2026 to reach USD 31.84 Billion by 2026.

https://www.yahoo.com/lifestyle/space-launch-services-market...

Including basically everything invested in space, not just launch, the pie is about $330B/yr now according to this:

https://www.airspacemag.com/daily-planet/cislunar-space-next...

Who knows what growth would be like with much cheaper launch but I'm hoping high.

Something that isn't well covered is the rocket motor supply chain. Prior to SpaceX there hadn't been a US manufacturer for heavy lift booster engines since the 90s. Undoubtedly SpaceX is the recipient of DoD funds to build that supply chain and research pipeline for both missile and lifting purposes.

Thomas Watson thought there was a market for maybe five computers in the whole world. Now computing devices outnumber humans. There's no guarantee that there will be a similar explosion in the size of the orbital (and eventually deep space) markets but it's not a large leap to believe that lower cost of access to space will open up many new opportunities that we haven't even imagined yet.