HERSCHEL

The biggest, most powerful infrared telescope ever placed in space, designed to study the origin of stars and galaxies. Named after Sir William Herschel, the German-born British astronomer who discovered Uranus in 1781.

Dimensions: 7.5 metres high (24.3 feet) and four metres (13 feet) wide. Launch mass of 3.4 tonnes.

Instruments: Three cameras and spectrometers, cooled to nearly absolute zero (minus 273.15 degrees Celsius, minus 459 degrees Fahrenheit), and a primary mirror 3.5 metres (11.37 feet) across, able to collect almost 20 times more light than any previous infrared space telescope.

Operational life: At least three years for routine observations, but can continue for a fourth year until the liquid helium used to cool its instruments runs out.

Mission cost: 1.1 billion euros (1.49 billion dollars)

PLANCK

Microwave observatory designed to look at radiation remnants from the "Big Bang" that created the Universe some 14 billion years ago. Named after the 20th-century German physicist Max Planck, founder of the quantum theory.

Dimensions: 4.2 metres (13.65 feet) high and 4.2 metres (13.65 feet) wide. Launch mass of 1.9 tonnes.

Instruments: 1.5-metre (4.8-feet) telescope that will focus radiation onto two arrays of detectors designed to measure the temperature of Cosmic Microwave Background (CMB) emissions.

Operational life: Fifteen months, enough to survey the whole sky twice over. Mission extension of one year is possible.

Mission cost: About 700 million euros (952 million dollars)

Source: ESA (http://www.esa.int)

All rights reserved. copyright 2018 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.