The Space Development Agency (SDA) on Oct. 5 awarded contracts worth $342.8 million for the development of the Wide Field of View (WFOV) program to help in the warning and tracking of advanced missile threats, including hypersonic missiles.

L3Harris Technologies [LHX] in Melbourne, Fla., received an almost $193.6 million contract, while California-based SpaceX received a nearly $149.2 million contract. Each company will build four space vehicles.

“These awards represent the next major step toward fielding the National Defense Space Architecture,” Derek Tournear, the SDA director, said in a statement. “The SDA tracking layer is an integral part of the department’s overall overhead persistent infrared (OPIR) strategy to detect, track, and defeat advanced missile threats. We are confident these fixed-price awards will help us deliver the initial tranche of the tracking layer on schedule.”

Tranche 0 of SDA’s tracking layer–the “warfighter immersion” tranche-consists of WFOV technologies contained within a proliferated low Earth orbit (LEO) satellite constellation.

SDA is to field the 28 Tranche 0 satellites in low earth orbit by the end of fiscal 2022. A much larger constellation with hundreds of satellites will follow by 2024.

The Missile Defense Agency’s (MDA) Hypersonic and Ballistic Tracking Space Sensor (HBTSS) Medium-Field-of-View (MFOV) space vehicles are to supplement the WFOV satellites, per SDA. MDA requested no funding for HBTSS in fiscal 2021.

In August, SDA awarded $281.5 million in firm, fixed-price contracts to Lockheed Martin [LMT] and York Space Systems to build 10 satellites each for Tranche 0 (Defense Daily, Sept. 1).

Lockheed Martin received a $187.5 million contract and York Space Systems a $94 million contract for the first generation of the National Defense Space Architecture’s Transport Layer.

The architecture will effectively be an optically-connected Internet in space to provide tactical data–low latency communications and targeting information–to military forces in the field.

The first layer of the National Defense Space Architecture to be fielded is a backbone data communications transport layer, with cross-linked space-based systems issuing communications directly to weapon systems and operators. The goal is to upgrade the layer’s capabilities every two years, with the satellites themselves being replaced every five years (Defense Daily, Sept. 20, 2019).

The satellites are to be the foundation of DoD’s Joint All-Domain Command and Control (JADC2) architecture to transfer tactical data from space to operating military units.