WASHINGTON — Lockheed Martin is planning to double its most advanced Patriot missile’s production in the coming years to deal with exploding orders of the weapon from the U.S. Army and its allies, according to a company executive.

The U.S. Army has dramatically increased its Patriot Advanced Capability-3 Missile Segment Enhancement, or PAC-3 MSE, orders to not just account for full-rate production of the missile but to increase the stockpile on hand as operations overseas continue to eat up the inventory.

The MSE version has a larger, dual-pulse solid-rocket motor and larger control fins that double the missile’s reach and improve performance against evolving ballistic and cruise missiles.

Meanwhile, several new customers abroad have joined the ranks of Patriot air and missile defense owners to include Poland, Romania and Sweden this year. This includes the purchase of a number of the MSE missiles as part of the initial order.

For example, Lockheed would build 576 PAC-3 MSEs just for the three European countries that recently signed on to buy Patriot.

Romania plans to buy 168 PAC-3 MSEs for its Patriot system as part of its order. Poland wants to buy 208 of them. Sweden intends to buy 200.

The reason for such an explosion in PAC-3 MSE buys is due to the proliferating threat both in the Middle East and in Europe as the U.S. and its allies remain embroiled in conflict in the Gulf region, and as European countries work to build up robust air defenses to deter Russia.

A comparison of the U.S. Army’s fiscal 2018 and fiscal 2019 budget justification documents show the service drastically increased its planned buys — in some cases more than doubling — across FY18 through FY22.

The Army had planned to buy roughly 95 missiles per year from FY18 through FY22, but a year later the service increased the 2018 order from 93 to 240 to include those bought with overseas contingency operations funds. In FY19, the Army asked for 240 missiles again. And the base orders for the missile in FY21 and FY22 total 160 each year.

The Army’s plans to dramatically increase its PAC-3 MSE production going forward has seen unanimous congressional approval, although the final FY19 defense appropriations bill has yet to become law. House and Senate appropriators are fully funding the production of 179 MSE missiles in FY19 in the base budget.

Lockheed is no longer selling its original PAC-3 missiles, but it is still producing them for one customer, according to Bob Delgado, director of international business development for integrated air and missile defense at Lockheed Martin, who spoke to Defense News in a recent interview at the defense conference Eurosatory in Paris.

This means Lockheed can make room for PAC-3 MSE production, which received the go-ahead to move into full-rate production by the U.S. Army in April.

“There is a lot of interest in [PAC-3 MSE], so much so we are doubling our capacity,” which equates to up to 500 of the missiles per year, Delgado said. This will likely mean adding an extra production line, he added.

Lockheed is currently meeting the demand, Delgado said, “however, it is getting more difficult as more orders come in, and that is why we are foreseeing, along with the U.S. government, a point where we need to increase our capacity.”

Lockheed expects to reach this capacity level within the next few years, he said, and the company could always build out to an even higher production capacity.

It also believed, according to a hint during a Raytheon earnings call earlier this year, that at least one more country that is not yet a Patriot customer will be taking steps to buy the system sometime this year, which could mean even more PAC-3 MSE orders for Lockheed.