What happens to a dark energy dream deferred?

An ambitious $1.6 billion spacecraft that would investigate the mysterious force that is apparently accelerating the expansion of the universe  and search out planets around other stars, to boot  might have to be postponed for a decade, NASA says, because of cost overruns and mismanagement on a separate project, the James Webb Space Telescope. The news has dismayed many American astronomers, who worry they will wind up playing second fiddle to their European counterparts in what they say is the deepest mystery in the universe.

“How many things can we do in our lifetime that will excite a generation of scientists?” asked Saul Perlmutter, an astronomer at the University of California, Berkeley, who is one of dark energy’s discoverers. There is a sense, he said, “that we’re starting to give up leadership in these important areas in fundamental physics.”

Last summer, after 10 years of debate and interagency wrangling, a prestigious committee from the National Academy of Sciences gave highest priority among big space projects in the coming decade to a satellite telescope that would take precise measure of dark energy, as it is known, and also look for planets beyond our solar system. The proposed project goes by the slightly unwieldy acronym Wfirst, for Wide-Field Infrared Survey Telescope.

The Academy’s report was ambushed by NASA’s announcement in November that the successor to the Hubble, the James Webb Space Telescope, which had been scheduled for a 2014 launching, would require at least another $1.6 billion and several more years to finish, pushing the next big mission to 2022 at the very earliest. The Webb will search out the first stars and galaxies to have formed in the universe, but is not designed for dark energy.