The U.S. House Power is including three dozen spacecraft to its rising constellation designed to detect and monitor incoming missiles from orbit. The House Growth Company (SDA) introduced the agreements, price a mixed $1.75 billion, on July 14, naming L3Harris Applied sciences and Sierra House because the recipients.
Every firm will present 18 Accelerated Missile Protection Tranche 3 (AMDT3) spacecraft, for a complete of 36 satellites that may develop the SDA Proliferated Warfighter House Structure’s Tranche 3 Monitoring Layer constellation, a part of the Trump Administration’s Golden Dome initiative. All 36 are anticipated to be prepared for launch by the top of 2028, based on an SDA assertion.
SDA’s contracts with every firm differ barely. One requires “18 missile warning and missile monitoring variant house automobiles” from Sierra House, whereas the opposite requests “18 missile protection variant house automobiles” from L3Harris, all outfitted with infrared sensors so as to add to the constellation’s international community.
L3Harris will obtain as much as $955 million for its 18 satellites, which the House Power describes as “Hypersonic and Ballistic Monitoring House Sensor-like” (HBTSS) spacecraft. Sierra House’s settlement has the potential to succeed in $798 million for its 18-satellite contribution. Altogether, the 36 spacecraft can be distributed throughout 4 orbital planes as a part of a hybrid missile-defense structure designed to offer “international stereo protection” of next-generation missile threats.
The Monitoring Layer makes use of infrared imaging in low Earth orbit to detect and monitor missiles, and it transfers that information in actual time via a low-latency communications community to army forces on the bottom. In keeping with the company, the brand new satellites will improve the constellation’s protection and combine into the spacecraft of SDA’s first three Tranches.
“AMDT3 expands upon SDA’s earlier and present Monitoring Layer generations — Tranches 1, 2 and three,” mentioned SDA Director G.P. Sandhoo, “marking one other milestone in delivering a resilient, international missile warning, missile monitoring, and missile protection functionality.”
Sierra House will base its satellites on the Horizon car, from the corporate’s Eclipse satellite tv for pc collection, which it additionally used within the design of the spacecraft it supplied for the Tranche 2 Monitoring Layer program, based on a Sierra House launch.
L3Harris plans to construct on the success of the HBTSS satellites the corporate developed for the Army Protection Company, based on an L3Harris launch. The corporate “has greater than 70 missile monitoring and protection satellites on order, together with 5 on orbit, between MDA’s HBTSS program and SDA’s Monitoring Layer throughout Tranche 0, 1, 2 and three,” the corporate mentioned.
The 36 satellites from L3Harris and Sierra House are along with the 72 Tranche 3 Monitoring Layer spacecraft SDA ordered in December 2025, through contracts price $3.5 billion. L3Harris was included in these agreements as effectively, together with Lockheed Martin, Rocket Lab and Northrop Grumman. In whole, the 2 rounds of awards convey the Tranche 3 constellation to a deliberate 108 satellites, price about $5.25 billion. If all goes to plan, all of them can be accessible to launch by the top of 2029.
The newly contracted satellites from L3Harris and Sierra House might start heading to house ahead of that, nonetheless. SDA describes the brand new contracts as “accelerated,” although a launch timeline has not been established to the general group. As soon as in orbit, the House Power will assume accountability for the satellites’ operation and integration “in assist of joint power operations and delivering warfighting capabilities,” the SDA assertion mentioned.
