LONG BEACH, Calif. — NASA is carrying out several studies that will support a decision in 2015 on what the U.S. space agency’s next major astrophysics mission should do, but officials cautioned that there may not be the budget or the political support to start a flagship mission immediately after the James Webb Space Telescope (JWST) clears development.
Paul Hertz, director of the Astrophysics Division of NASA’s Science Mission Directorate, told attendees of a NASA town hall meeting held during the meeting of the American Astronomical Society here Jan. 8 that the next opportunity to start a large astrophysics mission will begin in fiscal year 2017, when the budget for JWST ramps down as the $8 billion spacecraft nears completion ahead of its planned 2018 launch. To support a 2017 start date for the next astrophysics flagship, NASA will need to decide the mission’s parameters in 2015 in order to include funding in a 2017 budget proposal that will go to Congress in early 2016.
“The goal we’re working towards in the Astrophysics Division is to be prepared to start a strategic mission to follow the James Webb Space Telescope as soon as the funding becomes available,” Hertz said.
The National Research Council’s 2010 astrophysics decadal survey identified as its top-priority large, or flagship, mission a space observatory called the Wide-Field Infrared Survey Telescope (WFIRST). Hertz said NASA has completed studies on two different WFIRST concepts, one similar to the design described in the report and one that incorporates technology developments and a reduced mission lifetime to lower costs. A third study, looking at the use of one of two 2.4-meter telescopes donated to NASA by the National Reconnaissance Office last year to carry out the WFIRST mission, is scheduled to be completed by the end of April.
Hertz said WFIRST remained the agency’s top choice as the next major astrophysics mission, but warned that starting a large flagship mission immediately after JWST could encounter political resistance from the White House or Congress. “We can’t assume that we will be given permission to start a large mission immediately following JWST,” he said.
Since JWST was first proposed in 1996 as the Next Generation Space Telescope, its projected price tag was grown from $1.5 billion to the $8.8 billion sum NASA now expects to spend by the time the spacecraft has been on orbit five years.
To hedge its bets, NASA is also performing studies of several smaller “probe-class” missions, with budgets of no more than $1 billion, which could be started in 2017 instead in of WFIRST. On Jan. 4, NASA announced it was chartering two science and technology definition teams to examine concepts for probe-class missions devoted to studies of extrasolar planets. Those teams will file final reports by March 2015.
Complicating the long-term planning is uncertainty about near-term budgets, including the threat of across-the-board budget cuts from sequestration. NASA Associate Administrator for Science John Grunsfeld said at the town hall meeting that planning for sequestration started only the week before the original Jan. 2 deadline for the cuts to take effect. “We never got flow down of what the sequestration would have meant” before Congress passed legislation delaying those cuts by two months,” he said. “So we’re back to trying to work with the administration on an FY14 budget.”
While there has been no planning for what those cuts would do for NASA programs, Grunsfeld said he would seek to insulate JWST from any cuts that could further delay the mission. “My priority, and it is an agency priority, would be to try and protect the James Webb Space Telescope’s October 2018 launch,” he said.
At a Jan. 6 meeting of three NASA astrophysics program analysis groups here, Hertz offered similar guidance, although he cautioned it was not based on explicit guidance from NASA leadership but instead previous identification of JWST as one of three overall agency priorities.
“My interpretation of that is that even if we have sequestration, or flattening of the budget or reduction of the NASA bottom line, successfully executing JWST to its plan will remain a priority, which means JWST will not participate in the budget reduction,” he said.