Tag Archives: HyperSpectral Imager for Climate Science (HySICS)

Ballooning with carbon nanotubes on behalf of climate science

What a gorgeous picture!

Scientific balloon launched from New Mexico in September 2013 carrying an experimental instrument designed to collect and measure the energy of light emitted by the Sun, with the help of NIST chips coated with carbon nanotubes. Credit: LASP

Scientific balloon launched from New Mexico in September 2013 carrying an experimental instrument designed to collect and measure the energy of light emitted by the Sun, with the help of NIST chips coated with carbon nanotubes.
Credit: LASP

US National Institute of Standards and Technology (NIST) researchers made the carbon nanotube chips which help the instruments in the pictured balloon (above) to collect data about light. From the Oct. 24, 2013 news item on Nanowerk,,

A huge plastic balloon floated high in the skies over New Mexico on Sept. 29, 2013, carrying instruments to collect climate-related test data with the help of carbon nanotube chips made by the National Institute of Standards and Technology (NIST).

The onboard instrument was an experimental spectrometer designed to collect and measure visible and infrared wavelengths of light ranging from 350 to 2,300 nanometers. Simpler, lighter and less expensive than conventional counterparts, the spectrometer was tested to determine how accurately it can measure the relative energy of light emitted by the Sun and subsequently reflected or scattered by the Earth and Moon.

The Oct. 22, 2013 NIST news release, which originated the news item, provides some additional detail (Note: Footnotes have been removed),

Researchers at NIST’s Boulder, Colo., campus made the spectrometer’s “slit,” a high-precision chip that selected the entering light. The device was made under a recent agreement between NIST and the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP). The slit was then calibrated at NIST’s Gaithersburg, Md., headquarters.

For nearly a decade, NIST Boulder researchers have been using carbon nanotubes, the darkest material on Earth, to make coatings for laser power detectors. Nanotubes efficiently absorb nearly all light across a broad span of wavelengths, a useful feature for reducing internal scatter in the balloon imager. NIST also has facilities for, and expertise in, pairing nanotubes with micromachined silicon chips.

The Oct. 1, 2013 LASP (University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics) news release about the project offers information about the climate change data the researchers are hoping to collect and about the spectrometer being used for that purpose,

The instrument, funded by a $4.7 million NASA Earth Science Technology Office Instrument Incubator Program contract, is intended to acquire extremely accurate radiometric measurements of Earth relative to the incident sunlight. Over time, such measurements can tell scientists about changes in land-use, vegetation, urban landscape use, and atmospheric conditions on our planet. Such long-term radiometric measurements from the HyperSpectral Imager for Climate Science (HySICS) instrument can then help scientists identify the drivers of climate change.

Greg Kopp, HySICS Principal Investigator and CU-LASP research scientist, said, “HySICS allows us to acquire an accurate baseline of current Earth conditions so that we can monitor changes that are so relevant to society. This high altitude balloon flight was the first of two to demonstrate the instrument’s potential space capabilities needed to extend the measurements around the globe and over longer times.”

The instrument relies on precise measurements of the Sun for on-orbit calibrations. These solar measurements provide calibrations of the Earth measurements against this well-measured solar reference that other high accuracy space assets provide. Based on accurate solar calibrations, the HySICS radiometric measurements of the Earth can thus establish a long-term data record that is ten times more accurate than any current measurements.

For anyone interested in a more technical description of the device, the NIST news release has this,

For the balloon spectrometer, known as HySICS (HyperSpectral Imager for Climate Science), NIST made two types of custom chips that were stacked together in a sandwich. In the middle were aperture chips, coated with aluminum to block light transmission through the silicon, with small rectangular openings etched into the chip to allow light into the instrument.

A precision spectrometer must ensure that it only gathers light coming directly from its target, so the two outer layers of the sandwich were masking chips—larger openings etched at an angle and coated with tall, thin carbon nanotubes. These VANTAs (“vertically aligned nanotube arrays”) act as superefficient sponges to absorb scattered or stray light across the entire spectral range of the Sun.

While the balloon was in flight, the spectrometer scanned the slit across the Sun to measure solar irradiance. Spectral filters were calibrated by scanning the slit across the Moon and making measurements with and without filters in the beam path. The spectrometer also imaged light emitted from the Earth using the Sun as a reference light source.

For the information junkies amongst us, the Oct. 22, 2013 NIST news release offers links to more information about carbon nanotubes, etc. while the Oct. 1, 2013 LASP news release offers contact information for lead researcher, Greg Kopp.