Space Force AEHF-6 Satellite Completes On-Orbit Testing

Illustration of AEHF in orbit. Credit: Lockheed Martin

Earlier this year, ULA launched their first major payload for the U.S. Space Force with the sixth and final member of the Advanced Extremely High Frequency (AEHF) constellation of military communications satellites.

Built by Lockheed Martin and with a “protected communications payload” furnished by Northrop Grumman, AEHF-6 is the capstone of a fleet which will connect civilian leaders with their warfighters all around the world, and late last month the satellite completed on-orbit testing (OOT).

Credit: Jeff Seibert /

“Successful OOT demonstrates that all space vehicle performance requirements have been met and that we are on track for satellite control authority handover to Space Operations Command before the end of the year,” said Erik Daehler, director of Lockheed Martin’s Protected Communications mission area. “This is a great accomplishment for the industry-government team, bringing incredible capability for our warfighters.”

The network is intended to replace the outdated Milstar communications satellites and—as the name implies—it operates at extremely high frequencies (44 GHz uplink) and super-high frequencies (20 GHz downlink), with the capacity to relay communications directly without passing through ground stations. The AEHF phased-array antennas also aid with the elimination of potential radio-jamming and each satellite can support data rates as high as 8.192 Mbits/sec.

Overview of AEHF constellation and mission

The system incorporates advanced encryption, low probability of intercept and detection and an ability to penetrate the electromagnetic interference caused by nuclear weapons to route communications, real-time video, maps and targeting data to users on land, sea or in the air. The AEHF constellation provides complete surface coverage from 65 degrees North to 65 degrees South latitude.

Besides U.S. forces, the AEHF system also serves international partners Australia, Canada, the Netherlands and the United Kingdom.

written by Ben Evans and Mike Killian