Tag Archives: Vivek Dwivedi

NASA, super-black nanotechnology, and an International Space Station livestreamed event

Leave a reply

A super-black nanotechnology-enabled coating (first mentioned here in a July 18, 2013 posting featuring work by John Hagopian, an optics engineer at the US National Aeronautics and Space Administration [NASA’s] Goddard Space Flight Center on this project) is about to be tested in outer space. From an Oct. 23, 2014 news item on Nanowerk,

An emerging super-black nanotechnology that is to be tested for the first time this fall on the International Space Station will be applied to a complex, 3-D component critical for suppressing stray light in a new, smaller, less-expensive solar coronagraph designed to ultimately fly on the orbiting outpost or as a hosted payload on a commercial satellite.

The super-black carbon-nanotube coating, whose development is six years in the making, is a thin, highly uniform coating of multi-walled nanotubes made of pure carbon about 10,000 times thinner than a strand of human hair. Recently delivered to the International Space Station for testing, the coating is considered especially promising as a technology to reduce stray light, which can overwhelm faint signals that sensitive detectors are supposed to retrieve.

An Oct. 24, 2014 NASA news release by Lori Keesey, which originated the news item, further describes the work being done on the ground simultaneous to the tests on the International Space Station,

While the coating undergoes testing to determine its robustness in space, a team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, will apply the carbon-nanotube coating to a complex, cylindrically shaped baffle — a component that helps reduce stray light in telescopes.

Goddard optical engineer Qian Gong designed the baffle for a compact solar coronagraph that Principal Investigator Nat Gopalswamy is now developing. The goal is [to] build a solar coronagraph that could deploy on the International Space Station or as a hosted payload on a commercial satellite — a much-needed capability that could guarantee the continuation of important space weather-related measurements.

The effort will help determine whether the carbon nanotubes are as effective as black paint, the current state-of-the-art technology, for absorbing stray light in complex space instruments and components.

Preventing errant light is an especially tricky challenge for Gopalswamy’s team. “We have to have the right optical system and the best baffles going,” said Doug Rabin, a Goddard heliophysicist who studies diffraction and stray light in coronagraphs.

The new compact coronagraph — designed to reduce the mass, volume, and cost of traditional coronagraphs by about 50 percent — will use a single set of lenses, rather than a conventional three-stage system, to image the solar corona, and more particularly, coronal mass ejections (CMEs). These powerful bursts of solar material erupt and hurdle across the solar system, sometimes colliding with Earth’s protective magnetosphere and posing significant hazards to spacecraft and astronauts.

“Compact coronagraphs make greater demands on controlling stray light and diffraction,” Rabin explained, adding that the corona is a million times fainter than the sun’s photosphere. Coating the baffle or occulter with the carbon-nanotube material should improve the component’s overall performance by preventing stray light from reaching the focal plane and contaminating measurements.

The project is well timed and much needed, Rabin added.

Currently, the heliophysics community receives coronagraphic measurements from the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO).

“SOHO, which we launched in 1995, is one of our Great Observatories,” Rabin said. “But it won’t last forever.” Although somewhat newer, STEREO has operated in space since 2006. “If one of these systems fails, it will affect a lot of people inside and outside NASA, who study the sun and forecast space weather. Right now, we have no scheduled mission that will carry a solar coronagraph. We would like to get a compact coronagraph up there as soon as possible,” Rabin added.

Ground-based laboratory testing indicates it could be a good fit. Testing has proven that the coating absorbs 99.5 percent of the light in the ultraviolet and visible and 99.8 percent in the longer infrared bands due to the fact that the carbon atoms occupying the tiny nested tubes absorb the light and prevent it from reflecting off surfaces, said Goddard optics engineer John Hagopian, who is leading the technology’s advancement. Because only a tiny fraction of light reflects off the coating, the human eye and sensitive detectors see the material as black — in this case, extremely black.

“We’ve made great progress on the coating,” Hagopian said. “The fact the coatings have survived the trip to the space station already has raised the maturity of the technology to a level that qualifies them for flight use. In many ways the external exposure of the samples on the space station subjects them to a much harsher environment than components will ever see inside of an instrument.”

Given the need for a compact solar coronagraph, Hagopian said he’s especially excited about working with the instrument team. “This is an important instrument-development effort, and, of course, one that could showcase the effectiveness of our technology on 3-D parts,” he said, adding that the lion’s share of his work so far has concentrated on 2-D applications.

By teaming with Goddard technologist Vivek Dwivedi, Hagopian believes the baffle project now is within reach. Dwivedi is advancing a technique called atomic layer deposition (ALD) that lays down a catalyst layer necessary for carbon-nanotube growth on complex, 3-D parts. “Previous ALD chambers could only hold objects a few millimeters high, while the chamber Vivek has developed for us can accommodate objects 20 times bigger; a necessary step for baffles of this type,” Hagopian said.

Other NASA researchers have flown carbon nanotubes on the space station, but their samples were designed for structural applications, not stray-light suppression — a completely different use requiring that the material demonstrate greater absorption properties, Hagopian said.

“We have extreme stray light requirements. Let’s see how this turns out,” Rabin said.

The researchers from NASA have kindly made available an image of a baffle prior to receiving its super-black coating,

This is a close-up view of a baffle that will be coated with a carbon-nanotube coating. Image Credit: NASA Goddard/Paul Nikulla

This is a close-up view of a baffle that will be coated with a carbon-nanotube coating.
Image Credit: NASA Goddard/Paul Nikulla

There’s more information about the project in this August 12, 2014 NASA news release first announcing the upcoming test.

Serendipitously or not, NASA is hosting an interactive Space Technology Forum on Oct. 27, 2014 (this coming Monday) focusing on technologies being demonstrated on the International Space Station (ISS) according to an Oct. 20, 2014 NASA media advisory,

Media are invited to interact with NASA experts who will answer questions about technologies being demonstrated on the International Space Station (ISS) during “Destination Station: ISS Technology Forum” from 10 to 11 a.m. EDT (9 to 10 a.m. CDT [7 to 8 am PDT]) Monday, Oct. 27, at the U.S. Space & Rocket Center in Huntsville, Alabama.

The forum will be broadcast live on NASA Television and the agency’s website.

The Destination Station forums are a series of live, interactive panel discussions about the space station. This is the second in the series, and it will feature a discussion on how technologies are tested aboard the orbiting laboratory. Thousands of investigations have been performed on the space station, and although they provide benefits to people on Earth, they also prepare NASA to send humans farther into the solar system than ever before.

…

Forum panelists and exhibits will focus on space station environmental and life support systems; 3-D printing; Space Communications and Navigation (SCaN) systems; and Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES).

The forum’s panelists are:
– Jeffrey Sheehy, senior technologist in NASA’s Space Technology Mission Directorate
– Robyn Gatens, manager for space station System and Technology Demonstration, and Environmental Control Life Support System expert
– Jose Benavides, SPHERES chief engineer
– Rich Reinhart, principal investigator for the SCaN Testbed
– Niki Werkeiser, project manager for the space station 3-D printer

During the forum, questions will be taken from the audience, including media, students and social media participants. Online followers may submit questions via social media using the hashtag, #asknasa. [emphasis mine] …

The “Destination Station: ISS Technology Forum” coincides with the 7th Annual Von Braun Memorial Symposium at the University of Alabama in Huntsville Oct. 27-29. Media can attend the three-day symposium, which features NASA officials, including NASA Administrator Charles Bolden, Associate Administrator for Human Exploration and Operation William Gerstenmaier and Assistant Deputy Associate Administrator for Exploration Systems Development Bill Hill. Jean-Jacques Dordain, director general of the European Space Agency, will be a special guest speaker. Representatives from industry and academia also will be participating.

For NASA TV streaming video, scheduling and downlink information, visit:

http://www.nasa.gov/nasatv

For more information on the International Space Station and its crews, visit:

http://www.nasa.gov/station

I have checked out the livestreaming/tv site and it appears that registration is not required for access. Sadly, I don’t see any the ‘super-black’ coating team members mentioned in the news release on the list of forum participants.

ETA Oct. 27, 2014: You can check out Dexter Johnson’s Oct. 24, 2014 posting on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website for a little more information

Super-black nanotechnology, space exploration, and carbon nanotubes grown by atomic layer deposition (ALD)

Leave a reply

Super-black in this context means that very little light is reflected by the carbon nanotubes that a team at the US National Aeronautics and Space Administration (NASA) have produced. From a July 17, 2013 NASA news release (also here on EurekAlert),

A NASA engineer has achieved yet another milestone in his quest to advance an emerging super-black nanotechnology that promises to make spacecraft instruments more sensitive without enlarging their size.

A team led by John Hagopian, an optics engineer at NASA’s Goddard Space Flight Center in Greenbelt, Md., has demonstrated that it can grow a uniform layer of carbon nanotubes through the use of another emerging technology called atomic layer deposition or ALD. The marriage of the two technologies now means that NASA can grow nanotubes on three-dimensional components, such as complex baffles and tubes commonly used in optical instruments.

“The significance of this is that we have new tools that can make NASA instruments more sensitive without making our telescopes bigger and bigger,” Hagopian said. “This demonstrates the power of nanoscale technology, which is particularly applicable to a new class of less-expensive tiny satellites called Cubesats that NASA is developing to reduce the cost of space missions.”

(It’s the first time I’ve seen atomic layer deposition (ALD) described as an emerging technology; I’ve always thought of it as well established.)  Here’s a 2010 NASA video, which  provides a good explanation of this team’s work,

With the basic problem being less data due to light reflection from the instruments used to make the observations in space, the researchers determined that ALD might provide carbon nanotubes suitable for super-black instrumentation for space exploration. From the NASA news release,

To determine the viability of using ALD to create the catalyst layer, while Dwivedi [NASA Goddard co-investigator Vivek Dwivedi, University of Maryland] was building his new ALD reactor, Hagopian engaged through the Science Exchange the services of the Melbourne Centre for Nanofabrication (MCN), Australia’s largest nanofabrication research center. The Science Exchange is an online community marketplace where scientific service providers can offer their services. The NASA team delivered a number of components, including an intricately shaped occulter used in a new NASA-developed instrument for observing planets around other stars.

Through this collaboration, the Australian team fine-tuned the recipe for laying down the catalyst layer — in other words, the precise instructions detailing the type of precursor gas, the reactor temperature and pressure needed to deposit a uniform foundation. “The iron films that we deposited initially were not as uniform as other coatings we have worked with, so we needed a methodical development process to achieve the outcomes that NASA needed for the next step,” said Lachlan Hyde, MCN’s expert in ALD.

The Australian team succeeded, Hagopian said. “We have successfully grown carbon nanotubes on the samples we provided to MCN and they demonstrate properties very similar to those we’ve grown using other techniques for applying the catalyst layer. This has really opened up the possibilities for us. Our goal of ultimately applying a carbon-nanotube coating to complex instrument parts is nearly realized.”

For anyone who’d like a little more information about the Science Exchange, I posted about this scientific markeplace both on Sept. 2, 2011 after it was launched in August of that year and later on Dec. 19, 2011 in a followup about a specific nano project.

Getting back to super-black nanotechnology, here’s what the NASA team produced, from the news release,

During the research, Hagopian tuned the nano-based super-black material, making it ideal for this application, absorbing on average more than 99 percent of the ultraviolet, visible, infrared and far-infrared light that strikes it — a never-before-achieved milestone that now promises to open new frontiers in scientific discovery. The material consists of a thin coating of multi-walled carbon nanotubes about 10,000 times thinner than a strand of human hair.

Once a laboratory novelty grown only on silicon, the NASA team now grows these forests of vertical carbon tubes on commonly used spacecraft materials, such as titanium, copper and stainless steel. Tiny gaps between the tubes collect and trap light, while the carbon absorbs the photons, preventing them from reflecting off surfaces. Because only a small fraction of light reflects off the coating, the human eye and sensitive detectors see the material as black.

Before growing this forest of nanotubes on instrument parts, however, materials scientists must first deposit a highly uniform foundation or catalyst layer of iron oxide that supports the nanotube growth. For ALD, technicians do this by placing a component or some other substrate material inside a reactor chamber and sequentially pulsing different types of gases to create an ultra-thin film whose layers are literally no thicker than a single atom. Once applied, scientists then are ready to actually grow the carbon nanotubes. They place the component in another oven and heat the part to about 1,832  F (750 C). While it heats, the component is bathed in carbon-containing feedstock gas.

Congratulations to the team, I gather they’ve been working on this light absorption project for quite a while.