Soft launch (missile)

Soft launching is the method of launching a missile (such as an anti-tank guided missile) in such a way that the rocket motor ignites outside of the launch tube; the missile is ejected non-explosively. The point is to minimize the risk of damage to the launcher by maintaining a safe distance. Contrast this with hard launching.

A similar concept called cold launch was pioneered by the Soviets for application in vertical launch system clusters on board ships.

...
Wikipedia