The Northrop Grumman Aerospace Corporation is working with Elon Musk’s SpaceX on a network of spy satellites. Anonymous sources claim that prototype satellites have already been launched into orbit and are providing test intelligence to the National Reconnaissance Office, Reuters reports.

The program aims to enhance the U.S. government’s ability to track military and intelligence targets from low Earth orbit by providing high-resolution imagery that was previously obtained primarily through drones and reconnaissance aircraft.

Previously only SpaceX was working on this project. The involvement of Northrop Grumman reflects the government’s desire to avoid excessive control of the program in the hands of a single contractor, four people familiar with the project told Reuters.

Northrop Grumman is providing sensors for some SpaceX satellites. According to two sources, Northrop Grumman will test these satellites at its facilities before launch. In the coming years, at least 50 SpaceX satellites are expected to be tested and installed at Northrop Grumman facilities.

When only SpaceX was involved in the program, the contract was already worth $1.8 billion.

Northrop Grumman has a long history as a defense and intelligence contractor. It already provides the US government with products and services, including military satellites, spacecraft and space communications.

Once the new satellite spy network is fully deployed, it will be equipped with a variety of sensors, including optical and radar. The system will also include relay satellites that will be able to transmit images and other data through the network.