The relay satellites, which the SDA calls the transport layer, are also equipped with Ka-band and laser communication terminals for higher bandwidth connectivity.
“What the transport layer does is it extends beyond the line of sight,” Sandhoo said. “Now, you’re able to talk not only to within couple of miles with your Link 16 radios, (but) we can use space to, let’s say, go from Hawaii out to Guam using those tactical radios, using a space layer.”
The Space Development Agency’s “Tranche 1” architecture includes 154 operational satellites, 126 for data relay and 28 for missile tracking. With this illustration, the SDA does its best to show how the complex architecture is supposed to work.
Credit:
Space Development Agency
Another batch of SDA relay satellites will launch next month, and more will head to space in November. In all, it will take 10 launches to fully deploy the SDA’s Tranche 1 constellation. Six of those missions will carry data relay satellites, and four will carry satellites with sensors to detect and track missile launches. The Pentagon selected several contractors to build the satellites, so the military is not reliant on a single company. The builders of the SDA’s operational satellites include York, Lockheed Martin, Northrop Grumman, and L3Harris.
“We will increase coverage as we get the rest of those launches on orbit,” said Michael Eppolito, the SDA’s acting deputy director.
The satellites will connect with one another using inter-satellite laser links, creating a mesh network with sufficient range to provide regional communications, missile warning, and targeting coverage over the Western Pacific beginning in 2027. US Indo-Pacific Command, which oversees military operations in this region, is slated to become the first combatant command to take up use of the SDA’s satellite constellation.
This is not incidental. US officials see China as the nation’s primary strategic threat, and Indo-Pacific Command would be on the front lines of any future conflict between Chinese and US forces. The SDA has contracts in place for more than 270 second-generation, or Tranche 2 satellites, to further expand the network’s reach. There’s also a third generation in the works, but the Pentagon has paused part of the SDA’s Tranche 3 program to evaluate other architectures, including one offered by SpaceX.
Teaching tactical operators to use the new capabilities offered by the SDA’s satellite fleet could be just as challenging as building the network itself. To do this, the Pentagon plans to put soldiers, sailors, airmen, and marines through “warfighter immersion” training beginning next year. This training will allow US forces to “get used to using space from this construct,” Sandhoo said.