(Reuters) – Elon Musk’s SpaceX won a $149 million contract to build missile-tracking satellites for the Pentagon, the U.S. Space Development Agency (SDA) said on Monday, in the company’s first government contract to build satellites.

SpaceX, known for its reusable rockets and astronaut capsules, is ramping up satellite production for Starlink, a growing constellation of hundreds of internet-beaming satellites that chief executive Elon Musk hopes will generate enough revenue to help fund SpaceX’s interplanetary goals.

Under the SDA contract, SpaceX will use its Starlink assembly plant in Redmond, Washington, to build four satellites fitted with a wide-angle infrared missile-tracking sensor supplied by a subcontractor, an SDA official said.

Technology company L3 Harris Technologies Inc., formerly Harris Corporation, received $193 million to build another four satellites. Both companies are expected to deliver the satellites for launch by fall 2022.

The awards are part of the SDA’s first phase to procure satellites to detect and track missiles like intercontinental ballistic missiles (ICBMs), which can travel long distances and are challenging to track and intercept.

SpaceX in 2019 received $28 million from the Air Force to use the fledgling Starlink satellite network to test encrypted internet services with a number of military planes, though the Air Force has not ordered any Starlink satellites of its own.