In May, 2009 European Sapce Agency (ESA) successfully launched two of its most ambitious astronomy missions to unveil the sercrets of the darkest, coldest and oldest parts of the universe. Name the two most complex science satellites ever built in Europe used in this mission.

On May 14, 2009, the European Space Agency (ESA) successfully launched the Herschel Space Observatory and the Planck satellite together on a single Ariane 5 rocket from Kourou, French Guiana [t1][t3]. These missions were designed to explore the 'darkest, coldest, and oldest' parts of the universe. Herschel, featuring the largest mirror ever launched into space at 3.5 meters, was built to observe the 'cold' universe in far-infrared and submillimeter wavelengths, focusing on star and galaxy formation [t2][t3]. Planck was designed to map the Cosmic Microwave Background (CMB) radiation to study the 'oldest' light and the origins of the universe [t3][t4]. Both satellites utilized advanced cooling systems to maintain their detectors at temperatures near absolute zero, making them some of the most complex science satellites ever built in Europe [t3][t10].

Sources

1. [1] https://science.nasa.gov/mission/herschel-space-observatory/