An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new technologies that help to measure Earth's radiation imbalance, which is the difference between the amount of energy from the Sun that reaches Earth and the amount that is reflected and emitted back into space. That difference, estimated to be less than one percent, is responsible for global warming and climate change.
Designed to measure the amount of reflected solar and thermal energy that is emitted into space, RAVAN employs two technologies that have never before been used on an orbiting spacecraft: carbon nanotubes that absorb outbound radiation and a gallium phase change blackbody for calibration.
Among the blackest known materials, carbon nanotubes absorb virtually all energy across the electromagnetic spectrum. Their absorptive property makes them well suited for accurately measuring the amount of energy reflected and emitted from Earth.
Gallium is a metal that melts -- or changes phase -- at around body temperature, making it a consistent reference point. RAVAN's radiometers measure the amount of energy absorbed by the carbon nanotubes, and the gallium phase change cells monitor the stability of the radiometers.
RAVAN began collecting and sending radiation data on Jan. 25 and has now been in operation for well past its original six-month mission timeframe.
"We've been making Earth radiation measurements with the carbon nanotubes and doing calibrations with the gallium phase change cells, so we've successfully met our mission objectives," said Principal Investigator Bill Swartz of Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.
He and his team are now monitoring RAVAN in the longer term to see how much the instrument changes over time and are also performing data analysis and comparing its measurements with existing model simulations of outgoing Earth radiation.
While the technology demonstration comprises a single CubeSat, in practice a future RAVAN mission would operate many CubeSats in a constellation. Instruments for measuring Earth's outgoing energy are currently housed aboard a few large satellites, and while they have a high spatial resolution they cannot observe the entire planet simultaneously the way a constellation of RAVAN CubeSats could, Swartz explained.
"We know that outgoing radiation from Earth varies widely over time depending on variables such as clouds or aerosols or temperature changes," Swartz said. "A constellation can provide a global, 24/7 coverage that would improve these measurements."
"This successful technology demonstration realizes the potential of a new observation scenario to get at a very difficult measurement using constellation missions," said Charles Norton, program area associate for the Earth Science Technology Office (ESTO) at NASA's Jet Propulsion Laboratory in Pasadena, California. "In terms of its impact for CubeSats and Smallsats for NASA, I think It has helped to bring forward another example of how this platform can be successfully used for technology maturation, validation and science."
RAVAN and other Earth science CubeSat missions are funded and managed by NASA's Earth Science Technology Office (ESTO) in the Earth Science Division. ESTO supports technologists at NASA centers, industry and academia to develop and refine new methods for observing Earth from space, from information systems to new components and instruments.
Small satellites, including CubeSats, are playing an increasingly larger role in exploration, technology demonstration, scientific research and educational investigations at NASA, including: planetary space exploration; Earth observations; fundamental Earth and space science; and developing precursor science instruments like cutting-edge laser communications, satellite-to-satellite communications and autonomous movement capabilities.
Robert Gutro | EurekAlert!
Mars’ atmosphere well protected from the solar wind
08.12.2017 | Schwedischer Forschungsrat - The Swedish Research Council
Study reveals significant role of dust in mountain ecosystems
07.12.2017 | University of Wyoming
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology