Science Key to Tech Funding at NASA

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  Space News Business

Science Key to Tech Funding at NASA

By BRIAN BERGER
Space News Staff Writer
posted: 19 December 2007
03:10 pm ET





WASHINGTON





When it comes to investing in new technology for space science missions, NASA’s philosophy is that science is in the driver’s seat.

“We’ve decided we’re not investing in technology for technology’s sake and we need to make sure that these technologies we invest in [support] our mission set,” said Jim Green, director of NASA’s planetary science division.

Green manages a $1.3 billion annual




budget




that funds the development, launch and operation of orbiting observers and robotic landers sent to investigate the planets, moons, asteroids and comets of our solar system.

Within that




portfolio, only about $70 million is carved out solely and explicitly for the development of new technologies. And the technologies that pot of money goes toward




have some of the broadest applications to the planetary science division’s mission set.



The




division’s technology program is focused primarily on




advanced propulsion and new radioisotope




systems that can generate power in the absence of the sun’s rays. In the area of propulsion, a good example is a




next-generation version of the ion thrusters currently propelling NASA’s




Dawn spacecraft on its lengthy voyage to two of the solar system’s oldest surviving protoplanets, Vesta and Ceres.





Radioisotope power systems – long-lasting spacecraft batteries that convert heat from decaying plutonium-238 into electricity –




likely will






remain a major focus of NASA’s space science technology development efforts in the years ahead.

Today’s radioisotope power systems, such as the




radioisotope thermoelectric generator being built to supply power to the 2009 Mars Science Laboratory, are only about 4 percent efficient, according to Green. But a so-called Stirling-cycle system that Lockheed Martin has been working on for years in Valley Forge, Pa




., with NASA’s help is expected to be closer to 32 percent efficient and is




considered just about ready for prime time.

NASA put out a call for Discovery- and Mars Scout-class mission concepts this fall that would take advantage of recent breakthroughs in radioisotope power to explore




hard-to-reach solar system destinations previously considered off limits to all but the most complex




spacecraft




. Green said he expected at least 40 proposals to come in by the Nov. 30 deadline.

He hopes to select between eight and 10 of the mission concepts for




further study




and take the results to his boss, NASA Associate Administrator for Science Alan Stern, to make the case that the next Discovery solicitation – still more than a year away – should invite scientists to propose missions that would be powered by NASA-provided Stirling engines.



By making radioisotope power more affordable, Stirling-cycle engines have the potential to open up “new vistas




” for a budget-minded program that some scientists would say already has “picked all the low-hanging fruit,” Green said.

“If the Stirling engine works out for us, now we’ve got some new low-hanging fruit,” he said. “You are able to go to some places where the sun don’t shine. And there’s a ton of those.”





Green also said quite a bit of technology development occurs within the planetary science division’s various mission-focused programs and as part of its roughly $300 million




annual investment in research. The latter is




a broad category that pays for everything from extended mission operations and grant-based research and analysis to some of the early design




work on new classes of instruments.

Green cited the Planetary Instrument Definition and Development Program, or PIDDP, as a “fantastic workhorse” for taking immature instrument technologies and bringing them




to a higher level of




readiness.

“A number of instruments we’ve flown have grown up through the PIDDP,” Green said. “Unfortunately in the past we haven’t put much money into it. And I am bound and determined to put more money into it. It’s oversubscribed and there’s so many good ideas out there that indeed starting this year we will be investing more money in basic instrument technologies like that.” Green said.

Green also wants to invest




more in




instrument




technologies considered too mature for PIDDP funding




but still not ready to be assigned to a mission.





“We’ve done that in the Mars program already. The Mars instrument development program has allowed these higher [technology readiness-level] instruments in and much to its credit it’s really seen some positive results,” he said.

Astronomers, whose focus often is far beyond the reaches of our solar system, also




are




thinking about the technology investments




needed to




enable the big missions of the future.

During a recent conference in Baltimore focused on




future




space telescope missions, Jon Morse, who manages




NASA’s $1.5 billion-per-year




astrophysics program




, spoke about the importance of letting science drive technology development rather than the other way around.

For at least some of the technologists present, that approach is just fine, since nearly all astronomers can agree that when it comes to space telescopes: bigger is better.

Ron Polidan,




former chief technologist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and now




chief architect for civil space at Northrop Grumman Space Technology, said during the conference and in a subsequent interview that 20-meter-aperture space telescopes are feasible




by 2020 with the right investments.



The James Webb Space Telescope, which Northrop Grumman Space Technology of Redondo Beach, Calif., is building for NASA, will deploy a 6.5-meter segmented mirror after




it is launched in 2013.





Webb’s basic design was locked down several years ago but




Northrop Grumman has continued to invest




in




deployable optics research in order to make the most of any given rocket’s




payload shroud, Polidan said. Some of the




new approaches being studied, he said, would enable NASA’s planned




Ares 5 heavy-lift rocket to launch observatories




with primary mirrors nearly 10 times larger than the Hubble Space Telescope’s powerful main optic.

Polidan said he favors one approach called hexagonal stacking, in which six-sided segments are stacked for launch and then unfolded once in space. If it wants to demonstrate the technology on a smaller telescope before committing to a 20-meter behemoth, NASA could use the same hexagonal stacking approach to put a fairly substantial telescope on a rocket as small as a Delta 2, he said.





Harold Reitsema, director for space science




advanced programs at Ball Aerospace & Technologies Corp. of




Boulder, Colo.,




agreed that Ares 5’s huge 10-meter fairing is a potential bonanza for astronomers, with 20-meter apertures probably representing the upper limit of what is doable in the next 15 to 20 years.

“The problem with really large launch vehicles is it takes a tremendous amount of money to fill it with the best technology,” Reitsema said in an interview. He noted that




investments would be needed in new sensors and data-handling capabilities to take full advantage of the light-gathering potential of the very-large-aperture telescopes now being studied.