Rocket fuel: US Army expanding ammonium perchlorate sources for artill…

Aerojet Rocketdyne provides solid rocket motor boosters and other products for ‘hypersonic' weapons. (Aerojet Rocketdyne artist concept)

The US Army is in the midst of a massive effort to ramp up its production capacity for artillery, but will still have to contend with supply chains for the fuel that powers the in-demand rockets. Ammonium perchlorate (AP) – an oxidiser used in solid rocket fuels – is a crucial ingredient but can be difficult to source.

The number of approved sources for AP increased in recent years, US Office of the Secretary of Defense (OSD) spokesperson Jeff Jurgensen told Janes on 17 May. This comes as the demand for rockets in Ukraine has increased, and concerns about the supply chains for energetics materials have risen, experts said.

Earlier there was only one Department of Defense (DoD)-approved source of grade 1 AP (AP1) in the US, according to a report from the DoD Office of Inspector General (DoD IG) published in July 2020. AP1 is used in weapons employed by the army's Guided Multiple Launch Rocket System (GMLRS), for example. DoD IG said AP1 is used in 16 weapons in total across the DoD.

The tier-one rocket suppliers, ATK Launch Systems – which has since been acquired by Northrop Grumman – and Aerojet Rocketdyne, subcontracted AP1 from the American Pacific Corporation (AMPAC), previously the only DoD-approved domestic source of AP. When asked if the company subcontracted AP1 from AMPAC, Aerojet Rocketdyne referred Janes to the Pentagon.

Each programme in the DoD qualifies its own vendors to meet the requirements, Jurgensen said. Northrop Grumman Space Systems was qualified by a laboratory in 2021 to provide AP1, giving the US two domestic sources for AP.