I think it's important to be distinct here... These "Space DC" companies are not showing up on some Techy-Shark-Tank (or walking into VC meetings) with a promise to investors that they have an established strategy which will pay off.
IMO, they are just answering the question: "If we pour 100B into R&D, could it have a reasonable chance at succeeding?".
For Nvidia (or these other massive companies) the investment is chump change.