As astronomers gathered at the Space Telescope Science Institute here for three days of talks about the big missions they would like to tackle from

2020 onward

, NASA’s astrophysics chief warned them not to get stars in their eyes as they envision future budgets.

“I would encourage folks to think about the future optimistically, but we do have to live within realistic funding levels,” Jon Morse, the director of NASA’s astrophysics division, said Nov. 14 at the Astrophysics 2020 meeting.

NASA currently spends $1.5 billion, or about 9 percent of its total budget, on astronomy and astrophysics. But as the James Webb Space Telescope, the division’s largest project, begins to come down off its peak

funding years and five smaller spacecraft leave the launch pad over the course of the next two years, NASA’s current projections show the division’s annual budget

dipping to below $1.3 billion before starting to increase again about


“I want to make sure the community is fired up because astrophysics is a tremendous place to be working right now because of the discovery potential,” Morse said. “Nevertheless, we have to live within our means.”

Morse said the community should plan on only inflationary increases for astrophysics and astronomy in the decade ahead. Astronomers risk disappointment, he said, if they assume their share of the NASA budget will grow much beyond what it is today.

2020 might seem like a long way off for a space agency that writes and rewrites a new five-year budget plan every year. But the investments needed to enable the big flagship-class missions, such as the 20-meter aperture telescopes some astronomers were talking about here, will have to be made in the decade immediately ahead.

Morse said NASA’s future budget decisions will be guided by the recommendations of the next so-called decadal survey for astrophysics and astronomy, a 10-year plan to be developed by the National Academy of Sciences.


any of the scientists attending the meeting here will have a hand in shaping those recommendations.

The next decadal survey, which is expected to get under way in late 2009, will not only set the mission priorities for 2010-2020, but

also will recommend the other investments NASA needs to make during that period to lay the foundation for the missions that will take place in the following decade


If the panel the National Academy of Sciences charters to conduct the decadal survey assumes a budget trajectory “much more optimistic than anything like inflation, then I think we are going to have trouble delivering on the portfolio the community would like,” Morse said.

For an example of the consequences of a mismatch between priorities and budget, scientists need look no further than the 2000 decadal survey, Morse said.

“The Academy could come back and say, ‘

OK NASA, what’s your grade this decade for making progress on the decadal survey? How many missions did you launch that were on our list?’ The answer? One. GLAST,” Morse said, referring to the Gamma-ray Large Area Space Telescope, which is slated to launch in early 2008 from Florida aboard a Delta 2 rocket.

In all, the last decadal survey recommended nine space-based astronomy missions for NASA to tackle between 2000 and 2010, including the Solar Dynamics Observatory, an $800 million mission funded by NASA’s heliophysics division, that

also is slated to launch in 2008.

But besides GLAST and the Solar Dynamics Observatory, the only other mission from the 2000 decadal survey anywhere close to being accomplished is the James Webb Space Telescope (JWST), slated for launch in 2013.

Morse said the 2000 decadal survey did a commendable job of planning and prioritizing the science. Where it fell short, he said, was in estimating what the missions actually would cost. NASA, he said, shares the blame.

“What we collectively got wrong was the cost, and this has slammed shut the progress we’ve been able to make because the cost were much higher in reality,” Morse said.

The decadal survey put the total price tag for JWST, Constellation-X, Terrestrial Planet Finder and the Single Aperture Far-infrared Observatory at $2.1 billion.

JWST alone – the survey’s highest priority – now is expected to cost $4.5 billion by the time it completes its nominal

five-year mission around 2018. Constellation-X, an X-ray observatory designed to watch matter get sucked into super massive black holes, would cost around $2 billion should NASA decide to tackle it, according to a new estimate prepared for the National Academy earlier this year.

While some of the differences between estimated and actual cost can be explained by NASA’s transition in 2004 to full cost accounting, Morse said the earlier estimates

still were dramatically off base – something the agency learned as it got going on ambitious projects like Terrestrial Planet Finder only to shove them off into the indefinite future.

Not wanting to repeat the mistakes of the past, NASA and the National Academy are planning to inject more rigorous cost estimating procedures into the next decadal survey, Morse said, with NASA planning to foot the bill for independent assessments.


also is funding some advance work in the form of mission concept studies that will help scientists and their corporate sponsors flesh out their ideas for medium- and large-class missions ahead of the next decadal survey. Proposals are due Nov. 20 with awards expected early next year.

Better cost estimates alone will not guarantee that NASA can deliver on the recommendations of the next decadal survey, Morse said.

“We need to make sure we have better management and that mean’s controlling cost,” he said, citing the Kepler space telescope as an example where NASA’s Science Mission Directorate stepped in this year to rein in costs on the over budget mission, making management changes, cutting expenses

and forcing concessions from the contractor.

“We are going to try to make sure we exercise cost control because we want to value the future [mission] queue and not just throw tons of unanticipated resources into the projects that are in plan,” Morse said. “It just brings everything to a screeching halt.”

Whether Morse’s audience got the message remains to be seen. One astronomer questioned whether the community should just accept that their share of the budget will remain static, or whether they should fight for a bigger piece of the pie.