They’re on the launch pad right now. See here.
So, what are the missions and objectives of these fine spacecraft, I hear you ask.
Well, from the Planck site:
Planck will help provide answers to one of the most important sets of questions asked in modern science – how did the Universe begin, how did it evolve to the state we observe today, and how will it continue to evolve in the future? Planck’s objective is to analyse, with the highest accuracy ever achieved, the remnants of the radiation that filled the Universe immediately after the Big Bang, which we observe today as the Cosmic Microwave Background.
* Mapping of Cosmic Microwave Background anisotropies with improved sensitivity and angular resolution
* Determination of Hubble constant
* Testing inflationary models of the early Universe
* Measuring amplitude of structures in Cosmic Microwave Background
From the Herschel site:
The European Space Agency’s Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) has the largest single mirror ever built for a space telescope. At 3.5-metres in diameter the mirror will collect long-wavelength radiation from some of the coldest and most distant objects in the Universe. In addition, Herschel will be the only space observatory to cover a spectral range from the far infrared to sub-millimetre.
* Study the formation of galaxies in the early universe and their subsequent evolution
* Investigate the creation of stars and their interaction with the interstellar medium
* Observe the chemical composition of the atmospheres and surfaces of comets, planets and satellites
* Examine the molecular chemistry of the universe