York Space Systems (NYSE: YSS) is expanding into Geosynchronous Earth Orbit (GEO) as prime contractor on the U.S. Space Force's Tetra 3 and 4 missions, which the Denver-based company refers to internally as Nemesis.

The missions, focused on Space Domain Awareness (SDA), involve Resident Space Object tracking and Rendezvous and Proximity Operations demonstrations. York said the missions have cleared their Delta Critical Design Review, a formal customer approval to proceed to build, and remain on track for spacecraft delivery in the fourth quarter of this year.

As prime contractor, York is responsible for spacecraft design, sensor integration, and mission execution. Integrated payloads include a Long Wave Infrared camera, a LiDAR sensor capable of ranging resident space objects at 20 kilometers, and a GEO-qualified GPS Side Lobe Receiver.

The design review covered the addition of a new propulsion system. York said the change was incorporated without structural, thermal, or power impacts to the space vehicle and with no effect on launch vehicle integration.

"Absorbing a late-stage design change of this scope without cascading impacts is a defining requirement for prime integrators supporting national security missions," said Marc Cordova, VP of Programs at York.

York describes Nemesis as a ninth unique mission set within its national defense portfolio, which also includes assured communications, Synthetic Aperture Radar, and tactical warfighter support missions across multiple orbital regimes.

"Nemesis shows York can prime, integrate, and deliver against any mission our customers put in front of us, at any orbit," said Michael Lajczok, CTO of York.