A group of five people wearing cleanroom suits, hairnets, and masks watch a small gold and silver box suspended by a small crane in a laboratory. In the background, slightly out of focus, two more people watch through a window. Next to the window is a large decal of the COSI mission patch.UC Berkeley/Alan Toth UC Berkeley engineers and managers watch as the COSI (Compton Spectrometer and Imager) detector assembly is slowly raised from a table in this July 8, 2026, image. The four pieces of silver material on the top of the detector box cover the flex circuits, which carry signals from the detectors to the readout electronics.

COSI is a wide-field gamma-ray telescope that will study energetic phenomena in the Milky Way and beyond, including the creation and destruction of matter and antimatter and the final stages of the lives of stars. The mission is a collaboration between the University of California, Berkeley’s Space Sciences Laboratory; the University of California, San Diego; the Naval Research Laboratory; NASA’s Goddard Space Flight Center; Northrop Grumman; Space Dynamics Laboratory; the Italian Space Agency; and a number of research institutions.

Image credit: UC Berkeley/Alan Toth

COSI Telescope Comes Together