WASHINGTON — A pair of Hubble-sized telescopes given to NASA by the National Reconnaissance Office (NRO) could shave a quarter-billion dollars and years of development time off of the next big NASA astrophysics mission, agency officials said.

However, NASA will still have to find the money to develop a mission around NRO’s gifts, and to build the instruments necessary to turn the NRO hardware into working space telescopes, NASA Astrophysics Division Director Paul Hertz said during a June 4 press briefing. Much of the funding NASA could use for that is tied up with the $8.8 billion James Webb Space Telescope, a long-delayed budget-busting astrophysics flagship that is not scheduled to launch until 2018.

For now, NASA is studying whether to use one of the NRO telescopes — Hertz said he does not anticipate NASA “ever being rich enough to use both” — as a foundation for building the  Wide Field Infrared Survey Telescope (WFIRST). That dark energy mapping mission was recently identified as the astrophysics community’s top science priority after the Webb telescope.

Michael Moore, acting deputy director of NASA’s Astrophysics Division, said incorporating the NRO telescope into a future WFIRST design could save NASA about $250 million. WFIRST was conceived as a $1.6 billion mission. The mission’s steep price tag, combined with broader budget woes, prompted NASA to shelve WFIRST development earlier this year.

The NRO telescopes provide NASA with an optical system, including an advanced 2.4-meter-diameter primary mirror, that would take the space agency years to design and build itself. Former NASA astrophysics chief Jon Morse, now associate vice president for research at the Rensselaer Polytechnic Institute in Troy, N.Y., said the hardware could speed up the WFIRST development cycle by years.

“This could really accelerate WFIRST develop from the decadal survey-estimated seven years, starting from scratch, to something more like four years,” Morse said in an interview.

NRO contacted NASA in January 2011 about taking the telescopes off of the spy agency’s hands. NASA then had a team of six scientists evaluate the Earth observing telescopes’ suitability for astronomy missions, said one of the scientists who participated.

“We had about a month or so to ask optical design people about this,” said Alan Dressler, an astronomer at the Carnegie Institution for Science here. “We have reported back today in a very preliminary way. A month is not nearly enough time to study this, but we reported back that we thought the goals of the WFIRST mission could be done as well, if not better, with this obviously larger and more powerful telescope.”

Even with the gift of NRO hardware, Hertz doubts that WFIRST, or any mission like it would launch before 2024, given current budget projections.

“Our current budget planning doesn’t actually allow us to start a mission in the near future,” Hertz said. “So we will be looking at studies, whether these telescopes would be good in WFIRST and what such a mission would be like. But we’re also making all of our other mission study teams aware of the existence of these telescopes so they can ask questions to themselves for other missions.”

WFIRST was one of the casualties of James Webb’s cost overruns. The White House, in its 2013 budget request, sought no money for WFIRST, effectively signaling that the project would be on hold until the agency could find some other way to accomplish the science objectives for which the mission had been created.

The telescopes transferred to NASA by the NRO are currently in storage at ITT Exelis’ spacecraft optics facility in Rochester, N.Y.. NASA will pay between $75,000 and $100,000 a year for upkeep and storage, Moore said.

Any mission built around these telescopes will probably need to launch on a United Launch Alliance Atlas 5 rocket, Moore said.

“Certainly we need a fairly large fairing,” Moore said. “Today, yeah, you probably would need a small Atlas. In the future, whether Falcon 9s are available or other vehicles might show up that might have an equivalent shroud is really hard to predict right now.”

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.