SDA: Tranche 0 Link 16 Transmission In October, Second Launch In August

The U.S. Space Development Agency (SDA) has gotten authorization to broadcast the Link 16 datalink from recently launched satellites—but only over the open ocean, not in the national airspace.

SDA in April launched its first Tranche 0 data transport satellites, which will send the datalink to military cockpits and other receivers below. But the FAA had not signed off on the transmissions because it had not conducted electromagnetic certification tests, meaning the SDA could not meet its goal of beginning tests during large-scale exercises this summer. 

SDA Director Derek Tournear said July 18 that the FAA initially signed off on the open ocean transmissions but still has not provided the green light for transmissions in the national airspace. To begin tests, SDA now needs approval from the National Telecommunications and Information Administration. This is expected in time for tests to begin in October, he says. 

The agency had originally hoped for a temporary frequency evaluation from the FAA earlier this year to allow it to use a test stand it had built at Eglin AFB, Florida, for initial tests, but that has not happened yet. Tournear did not provide a timeline for anticipated FAA authorization for transmissions within the national airspace. 

Since SDA was not able to begin tests in time for major Northern Edge exercises in the Pacific, Tournear says the agency is targeting smaller, U.S. Marine Corps-led exercises in the region. 

A second launch of Tranche 0 satellites has been delayed, with the agency now expecting launch by the end of August. The delay has been because of crypto issues working with the National Security Agency, Tournear said during a Potomac Officer’s Association event outside Washington.

For Tranche 1 satellites, Tournear says the bulk of those have passed critical design review and are beginning to be produced. They will be ready for orbiting beginning in September 2024, with one launch per month for 11 months. Ground control stations for these are coming along as well, with operations centers at both Grand Forks AFB, North Dakota, and Redstone Arsenal, Alabama, being built and tests scheduled to begin next spring. Tranche 2 is in acquisition right now, broken into three phases known as Alpha, Beta and Gamma, based on different transmission frequencies.