In brief:

In a Jan. 31 draft solicitation, the agency seeks input from vendors interested in bidding for 72 satellites and supporting ground systems. Responses are due March 1. 

WASHINGTON — The Space Development Agency is planning a new procurement of 72 satellites to continue to build out a military constellation in low Earth orbit.

In a Jan. 31 draft solicitation, the agency seeks input from vendors interested in bidding for 72 satellites and supporting ground systems that will make up a portion of a planned 216-satellite Tranche 2 Transport Layer. Responses are due March 1. 

The Space Development Agency (SDA), an organization under the U.S. Space Force, is building a layered network of military satellites. The Transport Layer will serve as a tactical network to move data to users around the world, communicating classified data such as early warnings of missile launches.

The agency already has acquired satellites for Tranche 0 and Tranche 1 of the Transport Layer. The new solicitation is for 72 Tranche 2 Beta satellites. 

The first launch of Tranche 0 satellites is scheduled for March. Tranche 1 would launch in 2024 and Tranche 2 in 2026.

The proliferated constellation is made up of relatively small, mass-producible satellites supplied by multiple vendors, all interconnected in orbit via optical laser links.

SDA said the Tranche 2 Transport Layer satellites will be similar to those currently being developed by York Space, Lockheed Martin and Northrop Grumman for the Tranche 1 Transport Layer 

The Beta version of the Tranche 2 satellites will have three optical communications terminals, a Ka-band communications payload, a data routing payload, a navigation payload, an S-band backup control system, and will support two military classified communications networks: the Integrated Broadcast Service and TACSATCOM.

The 72 Beta satellites will be divided into six orbital planes, to be awarded to multiple vendors, said SDA. It asks vendors to submit proposals for two of the orbital planes, with the associated ground operations support.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...