May 8, 2009
ESA Prepares For Launch Of Herschel And Planck Telescopes
The European Space Agency is gearing up for this month's launch of two of the most sophisticated astronomical spacecraft ever built, the Herschel and Planck telescopes.
The instruments will orbit deep space around a special observation point beyond the Moon's orbit in a revolutionary campaign that will help scientists better understand the history of the Universe.
The two missions are among the most ambitious ever carried out by Europe.
Herschel, considered the largest far-infrared space telescope ever launched, is designed to study some of the coldest and most unexplored objects in space such as newborn stars and galaxies, asteroids and clouds of dust and gas, while the Planck telescope mission will accurately map the fossil light of the Universe, otherwise known as light from the Big Bang.
Each telescope is due to be launched aboard a shared Ariane 5 to begin their journey to the same area of space.
Both crafts will separate after launch and head independently towards the L2 Lagrangian point of the Sun-Earth system"”a gravitational stability point suspended in space some 1 million miles from Earth in the opposite direction to the Sun.
The telescopes also represent major technological achievements, as they are constructed of innovative materials. The primary detectors of the instruments on Herschel and Planck have to be kept as cold as possible to obtain high-resolution data through the background noise whilst making observations.
The ESA opted to build Herschel's primary mirror in twelve large segments of a ceramic material called Silicon Carbide (SiC).
The segments of the mirror were 'baked' like pottery in an oven as opposed to being traditionally cast before the segments were brazed together, creating the largest ceramic object ever built.
The material selected to build Planck's mirror includes carbon fiber reinforced plastic (CFRP), a lightweight composite more often used to manufacture satellite radio antennas and terrestrial boats.
Operating at unprecedented low temperatures, Planck will deliver unrivalled sensitivity and resolution to measure temperature variations in the very early Universe.
The satellite will take some 500 thousand million raw samples to produce a set of multi-million-pixel sky maps that will also help scientists to better understand the Universe's structure.
Planck will be able to infer the total density of dark matter and even shed new light on the nature of the mysterious dark energy by determining the total amount of atoms in the Universe.
The ESA has mobilized more than 100 industrial partners and institutes in Europe, the United States and elsewhere in the creation of Herschel and Planck.
The ten-year Herschel-Planck program will enable European industry to maintain and extend its skills in space-borne cryogenics, as originally built up during the agency's Infrared Space Observatory (ISO) program in the 1990s.
Image Caption: An Ariane 5 will carry Herschel and Planck into space. About 30 minutes after launch. The launcher's solid rocket boosters will separate from the upper stage approximately 2.5 minutes after launch, and the fairing will come off about 4 minutes after launch. Following this first Herschel, and then Planck, will separate from the upper stage. (ESA "“ D. Ducros 2009)
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