The first salvo of 800 missiles was fired at 50,000 kilometers. That may be within their range, but they would run out of fuel way before they arrived. As one reliable source says, it would take at least 6 hours for the missiles to even reach my formation, and that gives me enough time to move out of the way of the rockets that have no fuel to manuever to impact the ships.
Your source says that missiles only go 2.3 kilometers per second ?