XMM STM assembly and testing at ESTEC

The upper and lower modules of the XMM's Structural and Thermal Model (STM) are mated in one of ESTEC's cleanrooms in preparation for alignment, vibration and acoustic testing. ESA's X-ray Multi-Mirror (XMM) high-throughput X-ray spectroscopy mission will be launched by Ariane-5 in 1999. [Image Date: 1998/02] [98.03.005-003]