The European Space Agency (ESA) has announced it is to extend the lifetimes of seven key missions until 2014. The ESA-led probes, including the Planck microwave observatory and the Mars Express orbiter, will now take measurements for a further two years beyond 2012 – the previous end date for the missions.

The decision to operate the missions until 2014 was taken by ESA's Science Programme Committee (SPC) at a meeting in Paris last week. Five other ESA-led missions will be extended, including the Cluster probe studying the Earth's magnetosphere, the International Gamma-Ray Astrophysics Laboratory, the Venus Express orbiter, the X-ray observatory XMM-Newton and the Proba-2 satellite, which tests new types of space technology.

Waiting for the Sun

ESA’s contribution to four international projects, including the Cassini–Huygens mission to Saturn and the Hubble Space Telescope, will also continue until at least 2014. The other missions are Hinode, which was launched in 2006 by the Japanese Space Agency (JAXA), and NASA’s SOHO mission. The extension will allow the two probes to study the Sun during its next peak of magnetic activity, which is expected in 2013.

"It is a good day for European space science," says David Southwood, ESA’s director of science and robotic exploration. "It is not an easy time to make such commitments but we should not doubt the wisdom of the SPC in squeezing even more return from the big investments of the past."

Mapping the cosmos

ESA’s Planck probe, which was launched in April 2009, will map the cosmic microwave background (CMB) – a remnant of the Big Bang – in the finest detail yet. Planck carries two instruments: the high-frequency instrument (HFI) and the low-frequency instrument (LFI). The HFI will not operate beyond 2011, when it will run out of the liquid coolant needed to cool the instrument to a temperature of about 0.1 K.

However, the two-year extension will allow Planck to make further use of the LFI, which operates at about 20 K and measures the microwave sky with high sensitivity between 27 and 77 GHz. This will enable it to make better measurements of the CMB polarization. Nazzareno Mandolesi, principal investigator for the LFI told physicsworld.com that "This [extension] will improve the sensitivity of the LFI greatly, giving us the possibility to choose a region of the sky that we can more deeply observe."

However, some researchers warn of the need to maintain a balance between keeping operational satellites going and spending the money to build new ones instead."It is very difficult to argue against extending their operation to keep up the flow of excellent scientific data," says Matt Griffin of the University of Wales, Cardiff, and principal investigator of the Spire instrument on ESA's Herschel probe that was launched together with Planck. "Eventually though, some of them are going to have to be retired to make financial room for the next generation of missions."