Universities are insane places that promote violence, but it does absolutely no good to completely misdiagnose the problem. Universities are problematic because they pander to the students who scream in the middle of class and threaten the professor with violence. But sending a probe to the sun tells us what is happening at and above the surface of the sun, but nuclear fusion happens at the core. To try figure out what happens at the core, we need to make stellar models that are consistent with the data from the sun and other stars. In particular, we need a source of energy that can power the sun for billions of years. But we have plenty of fusion experiments including nuclear weapons tests and small amounts of fusion that we get when we propel atoms at very high speeds and subject them to very high temperatures.

Regards,

-Joseph Van Name Ph.D.

P.S. I got my degree in Mathematics, so nuclear fusion is only marginally related to what I have studied.