They're definitely advancing engineering. They're also significantly improving space transportation infrastructure, which is crucial to getting more space-related science (and that includes a lot of stuff that is of terrible importance to biotechnology, which is likely to be The Next Big Thing after IT). Apart from that, they're directly working towards making humans interplanetary species and - as we just learned - fixing communication infrastrucutre before that.
Add to that the amount of interest they generate among people - they're beginning to achieve what Star Trek did once, making space cool again. I personally know people who are dreaming (and some moving towards) aerospace career because of SpaceX, and with the amount of hype you see around the Internet, I'm pretty sure we'll soon have a generation of engineers inspired by Elon's companies.
Oh, and they do all that for dirt cheap.
I don't know how good they're on an absolute scale, or compared to the next best alternative, but they're definitely very cost-effective in terms of current and potential benefits to humanity.
Add to that the amount of interest they generate among people - they're beginning to achieve what Star Trek did once, making space cool again. I personally know people who are dreaming (and some moving towards) aerospace career because of SpaceX, and with the amount of hype you see around the Internet, I'm pretty sure we'll soon have a generation of engineers inspired by Elon's companies.
Oh, and they do all that for dirt cheap.
I don't know how good they're on an absolute scale, or compared to the next best alternative, but they're definitely very cost-effective in terms of current and potential benefits to humanity.