WASHINGTON, Sept 12 (Reuters) - Apex Space, a rapidly growing American startup focused on manufacturing spacecraft platforms at scale, has secured $200 million in new funding, valuing the company at $1 billion. This move comes as the U.S. Department of Defense ramps up interest in space-based defense systems.

Based in Los Angeles, Apex completed its Series D funding round with support from Interlagos, a venture capital firm created by former financial executives of SpaceX. Previous backers such as Andreessen Horowitz, Point72 Ventures, and 8VC also participated in the round.

Founded in 2022, Apex produces satellite buses that support both government and commercial payloads, including Earth observation tools and missile detection sensors. The latest investment will help the company increase its production rate by 50% and more than double the size of its manufacturing operations.

The recently announced $175 billion Golden Dome missile defense program under the previous administration has intensified private sector investment in low-Earth orbit defense technologies, a domain long led by SpaceX and its Starlink constellation.

Numerous American defense firms have expressed a desire to contribute to the Golden Dome initiative. However, the complete framework and schedule for the program are still being shaped.

The Golden Dome plan envisions missile interceptors based in space to neutralize incoming threats—an ambitious and controversial undertaking from both political and engineering standpoints.

In a statement, Apex indicated that its spacecraft systems could potentially support initiatives like Golden Dome, although the specific nature of their involvement remains undefined.

Rising geopolitical tensions among the U.S., China, and Russia have triggered increased Pentagon spending in space defense. China, for instance, has invested heavily in expanding its own satellite systems for military purposes.

For U.S. space firms, accelerating the delivery of satellites is now a strategic priority. This marks a significant shift from the traditional approach, where large, complex satellites could take several years to develop and deploy.