Goddard Engineering and Technology Directorate

Goddard’s ElectroMagnetic Anechoic Chamber (GEMAC)

A room with blue-gray polyurethane spires covering the walls, ceiling and much of the floor. A center column supports a white antenna dish
A room with blue-gray polyurethane spires covering the walls, ceiling and much of the floor. A center column supports a white antenna dish

Testing the Silence: Perfecting Space Signals

GEMAC (Goddard’s ElectroMagnetic Anechoic Chamber) is a world-class testing facility that has been supporting flight antenna testing since the 1970s. It plays a crucial role in assessing antenna performance for space missions, troubleshooting microwave radiating and reflecting devices, designing custom antennas, and measuring microwave instruments.

Each day, NASA’s communications network connects with over 100 space missions, maintaining essential contact with astronauts in orbit or exploring distant regions of the universe. At the core of each mission’s communication system is an antenna—without which space exploration and data transmission would be impossible.

To ensure antennas can withstand the challenges of spaceflight, they must undergo rigorous testing in environments that closely simulate the conditions of space. For more than 50 years, the GEMAC facility at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has served as the critical proving ground for this vital testing.

Inside the chamber, rows of cobalt-blue spires create a striking environment that resembles a soundproof room. However, instead of absorbing sound, GEMAC blocks out radio signals and eliminates wave reflections, ensuring a completely noise-free testing environment—”anechoic” means no echoes. This precise control over the testing conditions allows engineers to verify that antennas are ready for the extreme challenges of space communications.

The Goddard’s ElectroMagnetic Anechoic Chamber (GEMAC) is managed by ETD’s Electrical Engineering Division (Code 560). Contact ETD for more information.