Usually satellites do not communicate with each other, they transmit data to Earth via radio signals, where they then receive data from other satellites. However, recently two military satellites were able to exchange data directly, transmitting more than 200 gigabits over a distance of about 100 kilometers. On Thursday this was reported by CACI International, a company that develops optical terminals for space lasers.

Optical terminals are considered the fastest and most secure way to transmit data. With their help, two satellites called Able and Baker successfully communicated with each other during a 40-minute experiment. Infrared lasers transmitted data, encoding messages into optical signals, which were then transmitted to the receiver.

Both satellites were launched last summer by the US Advanced Defense Research Projects Agency (DARPA). The agency aims to set up a group of small satellites in low orbit to support military operations. As part of the Blackjack project, they first plan to launch a batch of 20 satellites that will communicate with each other, forming a space network.

Satellites will not compete with private projects like SpaceX’s Starlink. The goal of Blackjack is to create a constellation of state-owned satellites that can be used by the military to connect its bases, sensors, and weapons around the world.

20 satellites are planned to launch this fall, and another 125 units will be added by 2024. The full constellation will have 300 to 500 satellites in low orbit. They are being developed by Lockheed Martin, Northrop Grumman and York Space.