For nearly a decade, officials at NASA and the European Space Agency (ESA) have discussed a shared mission to study dark energy. But any substantive collaboration on Europe's dark energy mission, Euclid, now appears to be dead.
Last month, ESA green-lighted Euclid as a medium-class mission to be launched in 2019. After the decision was announced, NASA officials met with their ESA counterparts to discuss how NASA could contribute to the project. Such a partnership was seen as advantageous for U.S. astronomy, especially in light of an impending budget squeeze that could delay NASA's own dark energy mission until 2025 or later. Although no formal agreement was reached, the two sides agreed that NASA would contribute a piece of hardware such as detectors or reaction wheels—which help turn a space observatory in a desired direction—and, in turn, gain a seat on Euclid's 12-member science team.
That contribution is likely to be $20 million or less, said Geoffrey Yoder, acting director of NASA's astrophysics division, at a 21 November telecom of a NASA advisory panel. The figure represents a little over 3% of the $600 million project cost.