The European Space Agency’s (ESA) Planck mission, which will study the conditions present in our Universe shortly after the Big Bang, is reaching an important milestone with the integration of instruments into the satellite at Alcatel Alenia Space in Cannes, France.
Professor Keith Mason, Chief Executive Officer of the Particle Physics and Astronomy Research Council (PPARC), who fund the UK involvement in the mission, said, “Planck presents a tremendous opportunity to further our knowledge and understanding of the parameters that control the functioning of our Universe. The integration of the instruments into the spacecraft is a significant milestone that marks a major step towards launch next year.”
Planck will travel back to the dawn of time to investigate with the highest precision ever the cosmic microwave background (CMB) – the remnants of the radiation that filled the Universe immediately after the Big Bang some 14 billion years ago. Planck will be sensitive to temperature variations of a few millionths of a degree and will map the full sky in nine wavelengths. The tiny differences in the CMB are like the marks in a fossil, revealing details about the organism they come from – in this case, the physical processes at the beginning of the Universe.
The mission will address a number of fundamental questions, such as the initial conditions for the evolution of our Universe’s structure, the nature and amount of dark matter and the nature of dark energy and the expansion of the Universe itself.
Planck involves an international collaboration of scientists and industrialists from around the World. UK scientists from the University of Cambridge, Cardiff University, Imperial College London, University of Manchester, Jodrell Bank and Rutherford Appleton Laboratory have key roles – with involvement in the planning of the mission as well as building hardware for the sensitive instruments onboard, the data analysis and the science operations after launch.
Professor George Efstathiou, a member of the Planck science team and co-investigator on the High Frequency instrument (HFI) on Planck, from the University of Cambridge said, “The accuracy of the instruments on board Planck will allow us to measure the temperature variations across the cosmic microwave background with much better sensitivity than ever before providing astronomers with an unprecedented view of our Universe when it was extremely young – just 300,000 years old.”
Planck carries a 1.5 metre diameter telescope that feeds the microwave radiation to two instruments which will image the sky at different frequencies:- the Low Frequency Instrument (LFI) consisting of an array of ultra sensitive radiometers and the High Frequency Instrument (HFI), an array of highly sensitive microwave detectors known as bolometers.
The conditions that Planck will be studying present real challenges when it comes to the technological requirements of the instruments onboard. In order to achieve its science objectives, Planck’s detectors have to operate at very low and stable temperatures. The spacecraft is equipped with a sophisticated cryogenic cooling system which cools the instruments to levels close to absolute zero (-273.15 degrees C), ranging from -253 degrees Celsius to only a tenth of a degree above absolute zero.
Dr Tom Bradshaw from CCLRC’s Rutherford Appleton Laboratory works on the cooling system developed for the High Frequency Instrument. He comments, “Planck presents real technological challenges with regard to the temperatures that the instruments need to operate at. The spacecraft has a layered cooling system, akin to a Russian doll, which keeps the instruments cooled so that their own heat does not interfere with the science measurements.”
After integration which is due to be completed by the end of February, Planck will move to Liege in Belgium to undergo a series of tests to measure the performance of the instruments at extreme temperatures. Planck is scheduled to be launched on 31st July 2008 on an Ariane 5 rocket from Kourou in French Guiana. It will be launched in a dual configuration with Herschel, ESA’s mission to study the formation of galaxies, stars and planetary systems in the infrared. Once operational both missions will study different aspects of the “cold” cosmos providing complimentary information on previously unknown regions of the Universe.
Planck will build on the heritage of previous NASA CMB missions – Cosmic Background Explorer (COBE) and Wilkinson Map Anisotropy Probe (WMAP) – the latter of which is still operating. Professor George Smoot, lead scientist for COBE, who was awarded the 2006 Nobel Prize for Physics for his work on cosmic microwave background, is a co-investigator on Planck.
Contacts
Gill Ormrod – PPARC Press Office
Tel: 01793 442012. Mobile: 0781 8013509
Email: gill.ormrod@pparc.ac.uk
Franco Bonacina – ESA Media Relations Office
Tel: +33 1 53 69 7155.
Email: franco.bonacina1@esa.int
UK Science Contacts
Science team and High Frequency Instrument
Professor George Efstathiou, HFI Survey Scientist, University of Cambridge
Tel: 01223-337530 Email: gpe@ast.cam.ac.uk
High Frequency Instrument
Peter Ade, Cardiff University
Tel: 02920 8774643. Email: Peter.Ade@astro.cf.ac.uk
Andrew Jaffe, Imperial College London
Tel: 0207 5947526.
Email: a.jaffe@imperial.ac.uk
Professor Anthony Lasenby, Mullard Radio Astronomy Observatory, University of Cambridge
Tel: 01223 335573.
Email: a.n.lasenby@mrao.cam.ac.uk
Dr Tom Bradshaw, CCLRC Rutherford Appleton Laboratory
Tel: 01235 446149.
Email: Tom.Bradshaw@rl.ac.uk
Low Frequency Instrument
Dr Richard Davis, University of Manchester, Jodrell Bank
Tel: 01477 571321.
Email: rjd@jb.man.ac.uk
Notes to Editors
Images and information
PPARC – http://www.pparc.ac.uk/Nw/planck_images.asp
ESA – http://www.esa.int/esaSC/120398_index_0_m.html
Science Objectives of Planck
Planck’s maps will allow a number of specific investigations to take place:
- The determination of the Universe’s fundamental charcteristics such as the overall geometry of space, the density of normal matter and the rate at which the Universe is expanding.
- A test of whether the Universe passed through a period of rapidly accelerated expansion just after the Big Bang. This period is known as inflation.
- The search for “defects” in space, for example cosmic strings, that could indicate that the Universe fundamentally changed state early in its existence.
- Accurate measurement of the variations in the microwave background that grew into the largest structures today: filaments of galaxies and voids.
- A survey of the distorting effects of modern galaxy clusters on the microwave cosmic background radiation, giving the internal conditions of the gas in the galaxy clusters.
The Planck spacecraft was built by AAS Cannes, the prime contractor, leading a consortium of industrial partners with the AAS industry branch in Turin, Italy, responsible for the satellite’s service module. ESA and the Danish Space Centre are responsible for the hardware provision of Planck’s telescope mirrors, manufactured by EADS Astrium (Friedrichshafen, Germany).
AAS Cannes is also responsible for the payload module, the platform that hosts the telescope and the two onboard instruments, HFI and LFI. The instruments themselves are being supplied by a consortium of scientists and institutes led by the Institut’ d’Astrophysique Spatiale at Orsay (France) and in the case of HFI, and by the Instituto di’ Astrofiscia Spaziale e Fisica Cosmica (IASF) in Bologna (Italy) in the case of LFI).
The Particle Physics and Astronomy Research Council (PPARC) is the UK’s strategic science investment agency. It funds research, education and public understanding in four areas of science – particle physics, astronomy, cosmology and space science.
PPARC is government funded and provides research grants and studentships to scientists in British universities, gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Laboratory for Particle Physics (CERN), and the European Space Agency. It also contributes money for the UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility, which includes the Lovell Telescope at Jodrell Bank observatory.
PPARC is a partner in the British National Space Centre [BNSC] which coordinates the UK’s civil space activities.