Planck has run dry
19 Jan 2012 by Evoluted New Media
The Planck telescope is about to run out of coolant
Since 2009, a mixture of helium-3 and helium-4 has been cooling the light detectors on the Planck telescope to a freezing -237.05°C. However, the helium-3 refrigerant has run dry and engineers say the High Frequency Instrument (HFI) on board is about to become defunct.
“We always knew we would eventually lose HFI and the helium has run down exactly when we thought it would – on the dot,” said Dr Jan Tauber, the European Space Agency’s (ESA) Planck project scientist.
The systems will start to warm up from their ultra-frigid state before blinding the instrument. However, it’s not all bad news: Planck still has use of its Low Frequency Instrument – which can operate at a slightly higher temperature – for another six to nine months. And thanks to its uninterrupted science operations since August 2009, it has acquired five full scans of the sky – it was only expected to do two.
“I think we lost just one day,” Tauber said. “Planck has been perfect, we’ve never had a serious issue with the satellite or the instruments.”
“It’s a bittersweet moment; the prime phases of Planck’s observing will very soon be over, which is of course sad,” said Professor Mark McCaughrean, head of ESA’s research and scientific support department.
“But we have far more data in the bag than expected and its excellent stuff. People analysing it are really excited about what we’re going to learn about the early Universe, soon after the Big Bang.”
Planck was launched to survey Cosmic Microwave Background (CMB) – the first light visible once the Universe had cooled after the Big Bang to form hydrogen atoms. CMB covers the whole sky, and scientists can measure tiny variations in temperatures to yield information about the age, content and shape of the cosmos. Once the HFI fails, it will not be able to visualise CMB across all its frequency range.
It is hoped Planck will find firm evidence on inflation – the faster-than-light expansion that cosmologists believe the Universe experienced it its first moments.
