> different kind of cannon

How so? It's a cannon, just with a very long barrel and without the impractical "instant acceleration" issue. It's pretty much the only semi-realistic design.

> that affec any transportation method

Only that it doesn't. Rockets accelerate pretty slowly, at 1.5-2G, so they have no significant issues with crossing through atmosphere or with high-G loads during acceleration.

> if there’s a currently viable solution

Does SpinLaunch count or is it also "different kind of cannon"?