A SpaceX Falcon 9 rocket launched the T1TL-E mission from Space Launch Complex 4 East (SLC-4E), Vandenberg Space Force Base at 2032 UTC on Thursday (July 16) carrying 21 satellites for the U.S. military's Tranche 1 Transport Layer (T1TL) constellation.
The Falcon 9 first stage booster B1103, making its fourth flight, successfully landed on the droneship "Of Course I Still Love You" approximately 8.5 minutes after liftoff, according to SpaceX. The rocket's upper stage continued upwards, hauling the 21 satellites to low earth orbit (LEO).
The T1TL is a critical component of the Space Development Agency's (SDA) Proliferated Warfighter Space Architecture (PWSA), designed to provide global communications access and persistent regional encrypted connectivity for warfighters. It aims to deliver assured, resilient, and low-latency data to warfighter platforms worldwide.
The T1TL "will provide global communications access and deliver persistent regional encrypted connectivity in support of warfighter missions around the globe," SDA officials wrote.
The satellites are interconnected via optical crosslinks, offering significantly increased performance over existing radio frequency systems, including stereo coverage and greater bandwidth. The T1TL constellation is intended to be dynamically networked for simpler hand-offs and enhanced fault tolerance, supporting a wide range of military operations.
The PWSA is "a proliferated constellation of hundreds of optically linked small satellites, in low-Earth orbit (LEO), delivering capability at speed to the warfighter," SDA officials wrote in a Tranche 1 fact sheet. "SDA leverages spiral development to deploy and proliferate new capability into a new generation of the PWSA every two years, called a 'tranche,' to continually increase capability used by the warfighter."
This specific batch of 21 satellites, manufactured by York Space Systems, joins the constellation to help build out the planned 126-satellite network in LEO. The T1TL operates over the Ka band to ensure low-latency, resilient military data connectivity.
The T1TL will be built by York Space Systems, Lockheed Martin and Northrop Grumman. Sixty-three of the spacecraft have now launched to date, on three Falcon 9 launches from Vandenberg — one last September, another last October and today.