Musk owns 42% of SpaceX's total equity and 79% of the voting equity.
The non-Musk shareholders range from low-level SpaceX employees (equity compensation) through to Alphabet/Google, Fidelity, Founders Fund.
There are actually hundreds of investors. If you are ultra-wealthy, it isn't hard to invest in SpaceX. If you are the average person, they don't want to deal with you, the money you can bring to the table isn't worth the hassle–and the regulatory risk you represent is a lot higher
> How much of their balance sheet is debt vs equity?
I believe it is almost all equity, not debt.
There is such a huge demand to invest in them, they are able to attract all the investment they need through equity. Given the choice between them, like most companies, they prefer equity over debt. Plus, they have other mechanisms to avoid excessive dilution of Elon Musk's voting control (non-voting stock, they give him more stock as equity compensation)
> Given the choice between them, like most companies, they prefer equity over debt.
What do you mean by 'most companies'? Many companies use debt on their balance sheet just fine, and even prefer it. Banks, famously, have to be restrained from making their balance sheet almost all debt.
