The Herschel Planck mission

In spring 2009, Ariane 5 ECA will launch from the Guiana Space Centre and place two ESA scientific missions, Herschel and Planck, in orbit. These two independently-operated space telescopes are due to reach their final orbit around a virtual point located around 1.5 million kilometres from the Earth, the Second Lagrange Point (L2).  This spot is ideal for observing the Universe, being both stable and undisturbed by temperature variations caused by radiation from our planet, the Moon and the Sun.

Fitted with a 3.5m diameter mirror, Herschel will become the first space observatory to conduct photometric imaging and spectroscopy in the far infrared and submillimetre spectral range.

Meanwhile, Planck will help to provide answers to fundamental questions such as what caused the Big Bang, when precisely it occurred, and whether the observed expansion of the Universe will continue indefinitely, or on the contrary whether the Universe will collapse in on itself in a ‘Big Crunch’. [Source ESA]

7.5 m high, 4 m in diameter,

3.3 tonnes at launch

Herschel will study the formation of galaxies and stars, and the molecular chemistry of planets, comets and the atmospheres of satellites.

4.2 m high and in diameter,

1.9 tonnes at launch

Planck has been designed to measure, to the nearest thousandth of a degree, temperature fluctuations in relic radiation, also known as the Cosmic Microwave Background (CMB), which is found everywhere in the Universe and which constitutes a direct trace of the Big Bang.