I don't know how to purchase these shares, but the last time I checked there were two ways to buy SpaceX.
1. Buy Google - they owned a large stake in SpaceX. I don't know if this is true today.
2. Individual HNW investment, aka $500,000+ for private equity. Obviously not an option for most people (or myself).
I share your sentiment on very long-term prospects. Though of course there is a ton of risk that comes with these timeframes. E.g. see "NetScape" post - we don't know if competitors will emerge. We also still don't know the viability of asteroid mining and any true ability to get resources from the moon/Mars. Nor do we know if there are any filters that we haven't hit because we simply haven't done any commercial space travel.
