WASHINGTON — NASA’s Astrophysics Division should emulate the planetary science division and fund a line of competitively selected missions costing roughly $1 billion, the agency’s top astrophysics official told astronomers Oct. 21.

“I’m a big fan of an Astrophysics Probe line that’s analogous to the planetary science New Frontiers line,” NASA Astrophysics Director Paul Hertz said at the Goddard Space Flight Center in Greenbelt, Maryland, during a presentation to the agency-chartered NASA Advisory Council’s astrophysics subcommittee.

Like New Frontiers missions, the Astrophysics Probe line should be managed by a single principle investigator who would be responsible for keeping the mission on time and on budget, Hertz said.

NASA’s Astrophysics Division has a roughly $645 million annual budget. Some of that money funds the division’s Explorer line of competitively selected missions, the largest of which are capped at $200 million plus launch costs.

For an Astrophysics Probe line to become reality, the White House will have to request annual funding from Congress. This is likelier to happen if astronomers throw their weight behind Hertz’s proposal, which they could do in the next astrophysics decadal survey, which is due in 2020.

“I would love it if the decadal survey committee said, ‘Here are a handful of really compelling science ideas, science concepts, that ought to be doable in a medium-sized mission,’” said Hertz.

Decadal surveys are 10-year science roadmaps for the four major NASA science divisions published periodically by the National Academies. The last astrophysics decadal came out in 2010.

The next astrophysics decadal looms large because the nearly $9 billion James Webb Space Telescope (JWST) will — if all goes according to the plan NASA worked out in 2011 to get the program back on track after billions of dollars in cost growth — finally exit NASA’s development pipeline.

JWST, which has been managed separately from the Astrophysics Division since its 2011 program replan, accounts for more than $600 million in annual NASA spending. Astronomers are hopeful that money will return to the astrophysics budget after JWST launches in 2018.

Around that time, the astronomy community will start considering which flagship-class missions it should prioritize in the 2020 decadal survey. The 2010 decadal survey prioritized the Wide Field Infrared Survey Telescope as the post-JWST flagship, and the next decadal will anoint the flagship-class mission to follow that.

If Hertz can rally support for the Astrophysics Probe line, the 2020 decadal might also contain a prioritized list of missions astronomers deem worthy doing for $1 billion or less. If the Probe line follows the blueprint set by the New Frontiers program managed by NASA’s Planetary Science Division, only missions on the list would be allowed to compete for funding.

Current NASA spacecraft that would be considered Astrophysics Probe-class include the Fermi Gamma-ray Space Telescope launched in 2008 and the Kepler Space Telescope that launched in 2009, Hertz said.

Some lightly studied concept missions also fit the bill, said Hertz.

A 2013 report published by scientists at Goddard said an exoplanet-hunting telescope known as Exo-C could be built and launched for $950 million.

Likewise, a 2012 report produced at Goddard, the X-Ray Mission Concepts Study, detailed three X-ray telescope concepts scientists and engineers believe can be built for about $1 billion, Hertz said.

Hertz did not say how frequently he thought Astrophysics Probes missions might launch. New Frontiers has managed one mission every five years since the program started in 2002.

NASA’s Planetary Science Division has a roughly $1.5 billion annual budget. Astrophysics would have a comparable budget if the funds set aside each year for JWST are folded back into the Astrophysics Division after the telescope launches.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.