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June 29, 2004 – At the end of 2003, NASA scientists were “going big guns” on a project that would have launched what they called the first applied nanotechnology in space: a cooling system for the Hubble Space Telescope that used a layer of carbon nanotubes.
The nanolayer, an excellent conductor for extracting heat, would have helped keep the telescope’s imaging spectrometer cool and steady, and therefore provide clearer images.
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“The Space Telescope Imaging Spectrometer (STIS) is a pretty key instrument on the Hubble,” said Dan Powell, lead nanotechnologist at NASA’s Goddard Space Flight Center.
“The hotter things get, the more violently they wiggle and shake back and forth. … As the heat rejection capabilities of the STIS degraded, the quality of the images was also degrading,” said Powell.
Cancelled early this year, the effort that was to be part of a larger servicing mission in 2006 to extend Hubble’s life. NASA officials said they were complying with the safety recommendations of the Columbia Accident Investigation Board, formed after the Space Shuttle Coumbia accident.
But the cancellation also followed President Bush’s announcement to send astronauts to the moon and Mars, and NASA’s response that it would realign its priorities and programs to support the initiative.
Powell said he doesn’t question the wisdom of the decision, but admitted the timing was disappointing for nanotech’s literal and figurative launch. The project could have allowed the fledgling field to connect with the public, which has questioned nanotechnology’s safety, effectiveness and very existence.
“I would like to have been able to demonstrate real-world applicability sooner,” he said. “It’s difficult to convince a macro-oriented person, which is the common person in society, that nothing so small could be applicable or relevant to their everyday life.”
He said NASA now must work harder to develop nano’s next-best opportunity: nanotube-based chemical sensors developed at NASA’s Ames Center for Nanotechnology.
The sensors, which will be demonstrated on a U.S. Naval Academy flight in a couple of years, could help capture and characterize compounds in the atmosphere or on the ground on Mars, the moon or other planets.
The Naval Academy demonstration is just as valuable but “less sexy” than the thermal interface for the Hubble, which has been described as the most productive scientific enterprise in the agency’s history. Still, Powell believes hard work on the Hubble cooling system will pay off.
“Having a better way to extract heat out of instruments in space is always useful. We have hundreds of other instruments flying, all dealing with similar issues,” he explained.
Meyya Meyyappan, director of Ames’ Nanotechnology Center, has instructed his team to keep working on the heat dissipation problem. Potential uses in space and the ground have kept him from scrapping it.
“There’s also the broader impact of that: chip cooling for IC manufacturing,” Meyyappan said. “I just got an e-mail from a guy (with a company) on the East Coast. He found out we’re working on high-thermal conductivity. … He said, ‘Is it possible to have a conversation with you?’ That tells you there’s a much broader impact above and beyond the Hubble.”
Meyyappan believes nano will have its day, regardless of Washington. The current goals are still requiring lighter, stronger and smaller components. Nano is critical to the construction of spacecraft with materials that offer improved protection from radiation and miniaturized power systems with far longer life.
“The priorities of U.S. government can change; that’s part of the system,” Meyyappan said.
“In spite of that, actually, in a free country like this things have worked well for 200 years. There have been a couple of heartbreakers, as far as scientists are concerned … but people remember the cumulative advances these agencies have made,” he continued.
“We move on, based on good faith.”