[skybrian]

Sure, SpaceX has good business plan. That's the point. Building rockets only for a future Mars voyage and not making any money along the way would be a bad way to do it.

By contrast, fusion will only be a scientific research project for many years and many billions.

[inteleng]

That's just the way it works. It cost a lot of money to develop rockets in the first place. Your comparison is simply not very meaningful.

[skybrian]

My point is there is a big difference in how much money gets tied up for how long. (Capex.)