Security company Northrop Grumman (NYSE:NOC) saw shares spike at market open on Monday, after announcing a deal to buy rocket maker Orbital ATK (NYSE:OA).

The company confirmed the agreement would be worth about $7.8 billion in cash, with an offer price of $134.50 a share. This is around 22 percent higher than Orbital’s closing price on Friday.

The deal is one of Northrop’s biggest in several years, and signifies a deepening in their commitment to this market; last month Northrop won a $328 million contract to develop a intercontinental ballistic missile system for the US Air Force.

Orbital itself holds several contracts with US Army and NASA, and focuses on the building on both rockets and missiles. North Korea’s missile testing of late has renewed the US’s focus on this area and has renewed interest in the sector.

Northrop Grumman is currently trading up 1.44 percent at 270.88, with Orbital ATK shares shooting up 20.80 percent to 132.93 (1615GMT).