Cos-B telescope assembly

Lowering the anti-coincidence shield over the spark chamber of Cos-B's gamma-ray detector package at MBB. ESA's Cos-B, launched 9 August 1975, provided the first complete galactic survey in high-energy gamma-rays. Before this, the gamma-ray Universe had largely been invisible to astronomers. Designed for a 1-2 year life, it operated successfully until April 1982. [Image Date: 1974/02] [74.03.053-019]