Solid-fuel rockets are the dream weapons of military rocketeers. They have no pumps or valves to go wrong and are always ready to fire. Their big trouble is that they are harder to control than ...

The news outlets said the purported shipment could be transformed into enough ammonium perchlorate — a key solid fuel propellant component — to produce 260 midrange Iranian missiles.

Some designs do not require solid fuel, which eliminates the need for manufacturing and disposing of it. In recent years, growing interest in this technology has led to renewed development activities.

Axios reported in October that Israel had struck 12 “planetary mixers,” which Reuters said were “used to produce solid fuel for long-range ballistic missiles.” Iranian Armed Forces Chief ...