Nav: Home

A RAVAN in the sun

September 27, 2017

While people across the nation gazed at August's total solar eclipse from Earth, a bread loaf-sized NASA satellite had a front row seat for the astronomical event.

The Radiometer Assessment using Vertically Aligned Nanotubes, or RAVAN, CubeSat was developed to test and validate light-absorbing carbon nanotubes as a new method for measuring 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. The measurement is key for predicting changes in the planet's climate.

RAVAN began collecting data from Earth's orbit on Jan. 25, 2017, and the technology demonstration was declared a success in early August.

But the solar eclipse on Aug. 21 gave researchers a unique opportunity to further test an important carbon nanotube attribute: its strong sensitivity to rapidly changing energy outputs. While designed to measure the amount of reflected solar and thermal energy emitted from Earth into space, during the eclipse RAVAN's highly sensitive nanotubes would be trained instead on the sun to detect changes in the amount of incoming solar energy.

Because the researchers knew the CubeSat's location and the percentage of eclipse it would measure, it was easy for the team to compare the satellite's data to the known solar irradiance. Due to RAVAN's position in orbit, it did not catch eclipse totality -- where the moon completely blocks the sun's light. Instead, from its position high above the U.S., RAVAN was to collect data of an approximately 80 percent eclipse, similar as to what was observed from principal investigator Bill Swartz's home organization, the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, which leads the mission.

As the moon passed between Earth and the sun, RAVAN's instruments responded rapidly and accurately to measure the diminishing solar energy that was visible to the satellite's detectors. Swartz explained, "Although RAVAN routinely views the Sun for solar calibration, it tracked the sudden change in solar energy afforded by the eclipse as expected."

Now, with eclipse-tested technology, RAVAN is trained back at Earth as Swartz and his team continue to monitor the satellite's instrument performance, perform data analysis, and compare its measurements with existing model simulations of Earth's outgoing radiation.

RAVAN's current test and validation mission is the first step to enable a future constellation of CubeSats that would orbit Earth and provide continuous global coverage of Earth's radiation imbalance to improve on current measurements, which are taken by instruments housed on a few large satellites.

Having smaller satellites placed uniformly around the planet could offer an advantage when it comes to studying Earth's energy imbalance. "The radiant energy emerging from the Earth changes rapidly in time and space, particularly as viewed from a satellite constellation speeding along in low-Earth orbit," Swartz said. "The solar eclipse provided a unique opportunity to test the RAVAN measurement responsiveness in a controlled fashion, further proving the technique for Earth observation."

RAVAN was funded through a NASA Earth Science Technology Office (ESTO) program that demonstrates new technologies that, when validated, could be applied to a broad range of NASA Earth observation and science measurement needs. During their mission lifetimes, CubeSats like RAVAN are put through their paces to ascertain how well the new technologies and methodologies work in orbit.

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.
-end-
To learn more about ESTO and its programs, including the RAVAN mission, visit esto.nasa.gov.

NASA/Goddard Space Flight Center

Related Satellite Articles:

Satellite images reveal global poverty
How far have we come in achieving the UN's sustainable development goals that we are committed to nationally and internationally?
Satellite data exposes looting
Globally archaeological heritage is under threat by looting. The destruction of archaeological sites obliterates the basis for our understanding of ancient cultures and we lose our shared human past.
NASA satellite finds 16W now subtropical
NASA-NOAA's Suomi NPP satellite found 16W was still being battered by wind shear after transitioning into an extra-tropical cyclone.
How far to go for satellite cloud image forecasting into operation
Simulated satellite cloud images not only have the visualization of cloud imagery, but also can reflect more information about the model.
NASA confirms re-discovered IMAGE satellite
The identity of the satellite re-discovered on Jan. 20, 2018, has been confirmed as NASA's IMAGE satellite.
Satellite keeps an eye on US holiday travel weather
A satellite view of the US on Dec. 22 revealed holiday travelers on both coasts are running into wet weather.
Satellite shows Pilar reduced to remnants
Tropical Depression Pilar weakened to a remnant low pressure area as it continued to crawl north along the west coast of Mexico.
Satellite shows some shear in Hurricane Hilary
NOAA's GOES-West satellite revealed that vertical wind shear is affecting Hurricane Hilary.
Satellite view of a compact Hurricane Hilary
Imagery from NOAA's GOES-West satellite shows a more organized and compact Hurricane Hilary on July 24.
Satellite shows a weaker Hurricane Fernanda
Hurricane Fernanda appears to be weakening on infrared satellite imagery.
More Satellite News and Satellite Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.