ESA Panel Defers Decision on Japan-led Astronomy Mission

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PARIS Europe’s top space-science decision-making body has suspended a decision on whether to participate in a Japanese-led infrared space telescope pending further discussions with Japanese authorities on Tokyo’s commitment to the project and its proposed launch date, according to European Space Agency (ESA) officials.

Meeting Feb. 17-18 at ESA headquarters here, the Science Program Committee (SPC) endorsed a lower body’s recommendation that three space science mission proposals be selected for 18-month definition studies as the next phase in a competition that will end with only one or two of them being developed to launch around 2017.

The SPC warned that, given current budget restrictions, it is not certain that two of the three can be funded.

“What we are saying is that up to two [of the three] can make it,” SPC Chairman LennartNordh said in a Feb. 19 interview. “It depends on their final costs. Costs rarely go down when you start studying missions like these, and if you add in collaboration on a mission with the Japanese, we have very little financial flexibility.”

The SPC agreed to send three missions on to the next round of definition studies: The Euclid satellite to study dark energy; the Solar Orbiter spacecraft to be developed with NASA; and the Plato probe to search for Earth-like planets around nearby stars. All will be given closer examination to determine whether they can be kept within their development schedule and budget.

But the SPC stopped short of endorsing the Japan-led Space Infrared Telescope for Cosmology and Astrophysics. Nordh said the committee values the science potential from the mission but remains unclear about whether the Japanese space agency, JAXA, has confirmed a clear development schedule.

A JAXA official had appealed for European support for the joint project in a December meeting that led to the final SPC selection of the three missions, saying Europe’s participation is “essential to realize the mission.”

Nordh said the SPC asked ESA managers to confirm with JAXA exactly what the Japanese agency has in mind for the mission, for which Europe has been asked to provide the principal telescope. ESA officials have estimated that Europe’s minority stake in the telescope mission would cost around 160 million euros ($217.3 million).

One of the goals of the 18-month study phase for the three principal missions vying for the one or two places in ESA’s budget is to confirm that they can be built and launched within or at least not far from the cost ceiling of 475 million euros. All three are estimated by ESA to cost near or slightly above that figure.

Nordh said Euclid and Plato, for example, both will face challenges in keeping their total launch weight to within the limits of what can be carried into orbit by the European version of Russia’s Soyuz rocket, to be operated from Europe’s Guiana Space Center spaceport starting in late 2010 or 2011.