UPDATE: NRC Says Stick to Decadal Survey; Don't Commit to Joint Dark Energy Mission with ESA Yet

UPDATE: A link to a New York Times story on this subject that ran two days after we posted our story is provided at the end of this article.

NASA should not commit to a joint dark energy mission with the European Space Agency (ESA) quite yet according to a new report from the National Research Council (NRC).

Just three months after issuing its latest Decadal Survey for astronomy and astrophysics, the NRC convened a workshop, at White House request, to discuss how to implement those recommendations. The need for such a workshop so soon after the report’s release was fueled by the starkly changed fiscal circumstances at NASA’s astrophysics division mostly as a result of cost growth in the James Webb Space Telescope (JWST) program.

The NRC’s New Worlds New Horizons (NWNH) report, or Astro2010, prioritized ground- and space-based astronomy and astrophysics research for the next 10 years at NASA, the National Science Foundation (NSF) and the Department of Energy (DOE). The study committee created a set of missions for the next decade to fit within budget guidance provided by the three agencies, with its recommended missions segregated into large, medium and small categories. No cross-cutting set of priorities was made.

At NASA, however, funding expectations changed considerably during and after the study. Most recently, significant cost overruns on JWST and a slip in its launch date could have a dramatic impact on how much money is available to proceed with the NWNH recommendations.

The top NWNH recommendation for large space-based missions – the Wide Field Infrared Survey Telescope (WFIRST) – has become the poster child for figuring out how to deal with the problem. WFIRST has three goals: studying dark energy, conducting an infrared sky survey, and searching for exoplanets. Meanwhile, ESA is considering a dark energy mission, Euclid, for one of its upcoming M-class (medium-class) space science missions. Euclid is one of three missions vying for two slots. A decision is expected this summer.

NASA is proposing to the U.S. astrophysics community that the United States participate in Euclid at a 20 percent level in part because the outlook for proceeding with WFIRST on the time scale envisioned in NWNH is in doubt. Meanwhile, NASA says it would initiate planning for WFIRST and ESA would contribute a like amount to fly WFIRST at a later date.

NASA’s proposal has been very controversial in the U.S. astrophysics community. The White House Office of Science and Technology Policy (OSTP) asked the NRC to convene a panel to look at whether it is consistent with the NWNH recommendations. The NRC held a one-day workshop on November 7, 2010 to consider the issues and options.

The workshop report concluded that a joint WFIRST/Euclid mission could be consistent with NWNH if the United States plays a “leading role” and the science program recommended in NWNH “is preserved and overall cost savings result.” However, deciding to participate at a 20 percent level before ESA decides whether Euclid will win one of the M-class mission slots “is not consistent with the program, strategy, and intent of the decadal survey” because it would “deplete resources” needed for other NWNH priorities. Instead, the workshop report recommends waiting until the ESA decision is made. That will also provide time for the NRC to establish a Decadal Survey Implementation Advisory Committee (DSIAC) to provide further guidance on the matter. Creating DSIAC was one of the NWNH recommendations.

More broadly, however, the NRC workshop report stresses that NWNH did not say that large missions should have priority over medium missions, or medium missions over small missions, or that the top priority large mission “is the top overall priority of the program.” Rather, a central principle of NWNH “is the need for a balanced program….” Thus they do not want NASA to fund WFIRST at the expense of the medium and small missions also recommended in the report.

In fact, a final option identified in the workshop report is to not fund any space-based infrared telescope if the needed funds are not going to be provided and agreement cannot be reached on a joint WFIRST/Euclid mission that conforms with the NWNH advice. “Although an extremely unfortunate outcome with severely negative consequences,” such an option “would seem consistent with NWNH. However, such a major change of plan should first be reviewed by the DSIAC.”

The rapidly changing fiscal environment in NASA’s astrophysics division makes providing strategic advice to NASA today “extremely challenging,” the report says. Nonetheless, it continues, the Decadal Survey’s advice was “explicitly designed to be robust for the entire decade” and “The NWNH recommendations remain scientifically compelling, and this [workshop] panel believes that the decadal survey process remains the most effective way to provide community consensus to the federal government” on astrophysics research priorities.

Editor’s note: The New York Times ran a story on this topic on January 4, 2010, two days after ours. It has really good quotes from some of the most prominent scientists involved in the debate as well as Jon Morse, head of NASA’s astrophysics division. Well worth reading.