WASHINGTON — While NASA is stepping up plans to request concepts for its Discovery-class of planetary science missions later this year, it will miss by up to several months a congressional deadline for releasing that call for proposals, agency officials said Jan. 22 .

In the report accompanying the Consolidated Appropriations Act for 2014 that President Barack Obama signed into law Jan. 17, Congress called on NASA to “increase the tempo” of its Discovery program of missions, with specific language regarding the next announcement of opportunity (AO) for that program. “NASA is encouraged to initiate a new Discovery AO no later than May 1, 2014,” the report stated, with a selection of one or more missions by September 2015.

At a Jan. 22 meeting of the Planetary Science Subcommittee of the NASA Advisory Council here, however, James Green, director of NASA’s Planetary Science Division, said that schedule was not feasible. “They gave us the date of May 1st, and that’s not realistic,” Green said of the congressional language about the Discovery AO. Releasing the call for proposals so quickly, he said, “would catch everyone by surprise.”

Green said NASA will “maintain a rather brisk pace” preparing the next Discovery AO, with a goal of releasing it before the end of this fiscal year. A draft version of the AO is currently under development, he said, and will be released for public comment in advance of the final version. “We will soon establish a more realistic schedule” for the upcoming AO, he said. “We’ll certainly take into account the desires by Congress to get it out sooner rather than later.” 

Green did not indicate what he expected the schedule for selecting a mission would be once the AO was released later this year. NASA released the last Discovery AO in June 2010, choosing three mission concepts for further study in May 2011. NASA selected one of those three, the InSight Mars lander, in August 2012 for launch in 2016.

Green told the committee he appreciated Congress’ support for both the Discovery program and NASA’s planetary science program in general in the 2014 appropriations bill. “The budget is great news,” he said. “It provides adequate funding for our current ongoing missions and our extended missions, along with providing adequate funding to support our missions in development.”

The 2014 appropriations bill allocated $1.345 billion for NASA’s planetary science program, $127 million more than the administration’s request. However, $80 million is specifically set aside in the bill for studies of a proposed Europa mission that was not in the administration’s request, the same amount earmarked by Congress for that mission concept in 2013. Green told the committee Jan. 22 that NASA is “continuing to work with the administration to formulate our plans on how we would spend the $80 million” this fiscal year — meaning by the end of September — to support development of a mission.

While NASA is laying the groundwork for future missions, it is also making preparations for an upcoming “senior review” of ongoing planetary science missions. William Knopf, lead program executive for mission operations in NASA’s Planetary Science Division, told the committee that guidelines for preparing proposals for the senior review should be released at the end of January. Those guidelines, he said, will not include budget information, which will await the release of the 2015 budget proposal in February. Proposals will be due to NASA in April, with the agency making decisions on what missions to continue, and at what funding levels, in June.

That review has been a source of trepidation in the planetary science community, given projected flat budgets and the inclusion, for the first time, of two flagship-class missions: the Curiosity Mars rover and the Cassini Saturn orbiter. Some have worried there may not be sufficient funding to support both missions, with Cassini — slated to end its mission in September 2017 regardless of the outcome of the senior review — perceived to be in greater jeopardy of termination than Curiosity.

In presentations this month, however, Green said he would seek to keep all current missions operating, but perhaps with decreased budgets. “Each and every one of those missions may not be funded at the level that are funded at right now,” he told a meeting of the Outer Planets Assessment Group in Tucson, Ariz., Jan. 13. “Some may be at a lower level.”

Jeff Foust has more than a decade of experience writing about space policy, entrepreneurial ventures and regulatory affairs. In 2001, he established spacetoday.net to aggregate and summarize the day's space-related news stories. In 2003, he started The...