You'd still need to get your spaceship pair into an orbit (or at least a sharp sub-orbital hop) in order to excecute your plan though. the spaceship pair wouldn't just hang there in space. Also, it's simply not possible to mechanically push the two ships away from each other with sufficient velocity, and I imagine the explosives needed to blast your two ships apart would be better used in a smaller slower controlled explosion, often called a rocket engine.

There isn't a 'hack' for defeating orbital mechanics sadly. It takes expenditure of energy, and significant amounts of it.