Complex sentence: Bell returned a report stating that the missile could be upgraded to the required performance relatively easily, but the system would need extremely powerful radar systems in order to detect the warhead while it was still far enough away to give the missile time to launch.
Split into simpler sentences: Bell returned a report stating that the missile could be upgraded to the required performance relatively easily. But the system would need extremely powerful radar systems in order to detect the warhead while it was still far enough away to give the missile time to launch.