Virgin Orbit — one of the Virgin Group’s three primary space companies — has scored a deal with the Department of Defense, agreeing to launch experimental satellites for the agency on the company’s future LauncherOne rocket. The mission, slated for 2019, marks the first national security agreement for the private spaceflight company.

While its sister company Virgin Galactic is focused on space tourism, Virgin Orbit’s goal is to launch small satellites with its LauncherOne. The rocket is designed to take off from the air, after riding to an altitude of 35,000 feet under the wing of a Boeing 747-41R aircraft called Cosmic Girl. After dropping from the wing, Launcher One will fire its engine, carrying its payloads into orbit. Ultimately, the rocket can carry up to 1,100 pounds, perfect for small- to medium-sized satellites.

The mission is slated for 2019

Virgin Orbit already has a number of customers lined up to fly on LauncherOne, from commercial small satellite operators to NASA. But the venture is also interested in launching national security satellites. That’s why it recently formed a subsidiary known as VOX Space, aimed at setting up deals with the defense and intelligence community. “Anything where the payload itself needs to be handled in a secure facility, they will be involved in mission planning,” Will Pomerantz, vice president for special projects at Virgin Orbit, tells The Verge of VOX Space. “They’re there to keep both the physical stuff and data safe and secure.”

But first, Virgin Orbit needs to finish testing its rocket. The first complete LauncherOne test vehicle was recently transported from the company’s Long Beach factory to its testing facility in Mojave. “We’re really excited our first rocket has left the building,” says Pomerantz. “It puts us another step closer to our first flight.”

In Mojave, the vehicle will only be tested on the ground. Ultimately, the company plans to build around five LauncherOnes for testing over the next few months, Pomerantz says. In the meantime, the company has built most of its first orbital vehicle, which could launch for the first time early next year. If that launch is a success, Virgin Orbit will start putting customers on the next flights, according to Pomerantz.

Virgin Orbit’s LauncherOne program may also soon benefit from the Virgin Group’s recent deal with Saudi Arabia, which agreed to invest $1 billion in the company’s space ventures. The deal is still waiting approval by the US government, and it’s unclear how much of the investment Virgin Orbit will receive. But that much money could really help speed up the LauncherOne program — and make the vehicle active sooner than later.