The U.S. Space Force’s Space Development Agency (SDA) wants industry help to develop the agency’s Transport Layer Tranche 2 Demonstration and Experimentation System (T2DES) satellites for first launch in September 2026.

SDA “seeks U.S. corporation industry feedback on advanced tactical datalink and waveform maturity, on-going work with other U.S. Department of Defense (DOD) agencies on datalinks and waveforms, and integrating datalinks and waveforms on future tranches of the National Defense Space Architecture (NDSA),” SDA said on Nov. 14. “This would include risk reduction efforts to support command and control, sensor to shooter, and tactical satellite communication capabilities. [White paper] responses [by Dec. 15] to this RFI [Request for Information] will specifically inform SDA’s T2DES planning in FY2023 for subsequent contract award in FY2024.”

Last month, SDA said that it had awarded a firm-fixed price Other Transaction Authority prototype contract with a ceiling of about $200 million to Denver’s York Space Systems for 12 Tranche 1 Demonstration and Experimentation System (T1DES) satellites to demonstrate tactical satellite communications and Integrated Broadcast Service (IBS) from low Earth orbit (LEO) through 2031 (Defense Daily, Oct. 6).

The T1DES satellites and 28 Tranche 1 Tracking Layer satellites are to launch in fiscal 2025.

In May, SDA issued a draft solicitation for T1DES to explore future communications features for the NDSA’s Transport Layer (Defense Daily, May 24). Across several layers, the NDSA is to have 300 to 500 satellites.

The Transport Layer’s LEO satellites, which are to be optically linked, are to be the foundation for Pentagon Joint All Domain Command and Control.

For the T2DES satellites, SDA is soliciting input from companies that have “Direct Line of Sight (DLOS), Protected Tactical Waveform (PTW), Protected Forward Communications (PFC), Tactical Targeting Network Technology
(TTNT), or any other datalink/waveform that can integrate into existing, space-qualified radio or any other mature (TRL 5 or better) software defined radio.” SDA asks such companies to assess how their technologies are compatible with LEO operatins at 600 miles above the Earth.

In addition, SDA wants to hear from companies that are pursuing other advanced tactical datalinks and waveforms for DoD. SDA wants such companies to provide the estimated costs and schedule to demonstrate a capability of TRL- 7 from LEO.

In February, SDA announced nearly $1.8 billion in awards to Lockheed Martin [LMT], Northrop Grumman [NOC], and York Space Systems for 126 prototype satellites for the NDSA’s Tranche 1 Transport Layer–the SDA’s first stab at fielding operational satellites to provide resilient, high volume, minimal lag time communications for military missions (Defense Daily, Feb. 28). Each contractor is to build 42 satellites to be ready for launch by September 2024. Lockheed Martin won $700 million, Northrop Grumman $692 million, and York Space Systems won $382 million.

While the 126 Tranche 1 Transport Layer satellites are to use Ka-band radio frequency up and downlinks, optical up and downlinks, and existing L-band radios with Link 16 for the transmission of time sensitive targeting data to U.S. forces in the field, the T1DES satellites are to use new radios.

“For the T1DES satellites, they will utilize different radios that go down to special users in the field and special platforms utilizing the UHF and S-band frequencies that are not going directly down via Link 16, or Ka, or optical,” SDA Director Derek Tournear told reporters last month. “Those capabilities, especially, for example, the IBS, is typically handled by geosynchronous satellites today. Because of that, there are a lot of technical challenges that we need to [work through] to show that the technology can be applied moving it from geosynchronous down to LEO where you have Doppler shift differences and things like that.”