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A Group of Suitcase-Sized Satellites Will Transform Hurricane Tracking

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Screenshot from "CYGNSS Overview," NASA Langley Research Center

Earlier this month, NASA launched a constellation of small satellites that will transform hurricane forecasting and enable new insights into storm formation and activity. Called the Cyclone Global Navigation Satellite System (CYGNSS), eight spacecraft, each the size of a carry-on suitcase, are flying over the tropics to measure and map ocean winds. Because of their altitude, heavy rain and storm surges are no obstacles to the satellites, and when hurricanes form, the spacecraft will be able to peer through walls of water into the storm’s core and continue to collect data—something no space-based system has ever done before.

“CYGNSS is a tool that will provide us 24/7 coverage of the tropical cyclone zone. It will improve our knowledge of how hurricanes grow so that we can better prepare and protect people in the path of each hurricane as it comes,” Christine Bonniksen, CYGNSS program executive with the Science Mission Directorate's Earth Science Division at NASA Headquarters, tells mental_floss.

THE RAIN BARRIER HAS BLOCKED OUR VIEW

Over the past several decades, there has been a steady improvement in storm track forecasting—or where storms will hit—and the National Hurricane Center’s error rate is half of what it was 20 years ago. The same cannot be said for storm intensity forecasting—how strong these storms will be. “If you look at the record for their intensity forecast, there has been very, very little improvement in the last 20 years,” said Chris Ruf, the principal investigator on the CYGNSS mission and a scientist at the University of Michigan, Ann Arbor. One of the primary reasons for this is that today’s satellites are unable to measure what’s going on in the inner core of hurricanes. “This has been identified for many years as a primary lacking ingredient in the numerical forecasts that are used by the National Hurricane Center. They wish they had information on the inner core of the storms and they don’t.”

Storm cores have so far been impenetrable because current wind-observing spacecraft cannot see through rain. This is because their on-board instruments emit signals at an 8-millimeter wavelength—about the same size as a large raindrop. When the signals encounter rain, they are simply scattered and absorbed. (Hurricane paths depend on environmental factors outside of the storm, which is why this rain shroud has not been an impediment to predicting where storms will hit.)

Additionally, it takes about three days for current systems to collect data to build a map of global wind speeds and precipitation. This is a big problem if you’re trying to track the rapid intensification of tropical storms and hurricanes, which can happen in a matter of hours. So until now, scientists have had to rely on so-called “Hurricane Hunter” aircraft to fly into the storm to perform wind speed reconnaissance.

THE CYGNSS SOLUTION

CYGNSS changes all of this by using GPS satellite signals, which were designed to penetrate heavy rains. GPS operates at a 19-centimeter wavelength—more than long enough to avoid rain interaction. When GPS satellite signals hit the ocean, they reflect back into space and are received by CYGNSS observatories. Think about the way the Moon reflects on a placid lake: When the lake is calm, the Moon's image is sharp. When the wind blows, the water roughens and the image diffuses. CYGNSS relies on a similar principle, reading the clarity of the GPS signals to reveal the characteristics of the wind. It measures the strength of the GPS signal as it scatters off the ocean surface to determine wind speed.

The eight CYGNSS observatory spacecraft operate evenly in a single orbital plane around the Earth. Each satellite has a payload called a Delay Doppler Mapping Instrument, a GPS receiver capable of tracking four different GPS signals simultaneously. Two antennas look down at reflected GPS signal and take measurements of the diffuse scattering, and from those derive the wind speed and activity. Meanwhile, one antenna looks up and receives a direct GPS satellite signal for geolocation. In essence, each 65-pound satellite is doing the work of four Hurricane Hunter airplanes. Collectively, CYGNSS is like a squadron of 32 such planes flying continuously over the tropics taking simultaneous measurements.

The system gives a total refresh of the entire tropical wind distribution map every seven hours, even under heavy precipitation. In a hurricane or tropical storm—including in areas with the highest wind speeds and the most powerful surges—CYGNSS can immediately answer questions about the storm size, intensity, and the reach of its strong winds. Moreover, because the satellite constellation has such expansive coverage of the Earth, it can collect massive amounts of data on the entire storm environment. There are three different data downlink points around the world, and the data can be downloaded from the satellites within the hour—an unprecedented timeframe.

HOW THE LAUNCH WENT DOWN

CYGNSS launched on the morning of December 15, 2016 from Cape Canaveral with the help of a Pegasus rocket, an air launch system. The rocket was mounted to the bottom of an L-1011 airplane called Stargazer that took off from a runway, just like any other plane you’ve ever seen. At 39,000 feet above the Atlantic Ocean, the plane released the Pegasus rocket, which ignited five seconds later and powered its way into space. The fairings hatched away and the deployment vehicle separated, and the eight small satellites released themselves in pairs over 30-second intervals. Ten minutes after separation, their solar arrays deployed. They then moved into position in orbit and began operation.

By 4:12 pm ET that same day, the CYGNSS team had successfully made contact with all eight satellites. "It is an amazingly rewarding feeling to spend such an intense and focused time working on CYGNSS and then, in a matter of just a few hours, have the entire constellation suddenly come to life," Ruf said in a brief mission update. "I am excited (and a little exhausted) and really looking forward to diving into the engineering data in the coming days, and then into the science data in the weeks to follow."

This is NASA’s flagship Earth Venture–class mission, which is a new NASA program designed for low-cost, high-technology suborbital (think aircraft and balloons) and orbital (CYGNSS) projects. Two previous missions of this class were aircraft designed for atmospheric research and communications. This is the first spaceborne Earth Venture endeavor. Southwest Research Institute in Boulder, Colorado runs CYGNSS mission operations, and science operations are run from the University of Michigan. The primary $160 million mission will run for two years—enough time to fill in blank spots in the hurricane dataset, get a grip on how storm cores intensify, and hopefully refine the forecast models that lives depend on.  

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science
11 Out-of-This-World Facts About Carl Sagan
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Hulton Archive/Getty Images

Carl Sagan was perhaps America’s most beloved scientific visionary since Albert Einstein. Both a gifted astronomy researcher and an incredible communicator, he brought the wonders of the universe to the masses with his popular TV series Cosmos and books like the Pulitzer Prize–winning Dragons of Eden and Pale Blue Dot. His only novel, Contact, later became a sci-fi movie starring Jodie Foster and Matthew McConaughey. Here are a few things you might not know about the scientist, TV star, and amateur turtleneck model.

1. HARVARD PASSED ON HIRING HIM.

After Sagan served five years at the esteemed university as an assistant professor, Harvard denied him tenure in 1967, in part because one of his mentors at the University of Chicago derided his work as needlessly wordy and useless. He took a job at Cornell instead, where he stayed on as a professor until his death in 1996.

2. HE DICTATED ALL OF HIS WRITING TO AN AUDIO RECORDER.

Carl Sagan standing with a model of the Viking Lander.
JPL via Wikimedia Commons // Public Domain

Sagan was an avid self-editor. A total of 20 drafts of Sagan’s 1994 book Pale Blue Dot exist today in the Library of Congress, each filled with handwritten edits, annotations, and revisions by the author. However, he drafted all of his writing—even grant proposals—by dictating his ideas onto a cassette. The contents were then transcribed for him and returned for editing.

3. HE CONSIDERED WRITING A CHILDREN’S BOOK CALLED HOW DO BIRDS FLY?

In 1993, Sagan brainstormed a long list of possible children’s books for a series structured around the theme of “why?” Other potential ideas included Why Is It Warm In Summer?, Why Are There Lakes?, and What Is Air?

4. HE DIDN’T LIKE THE SPACE SHUTTLE PROGRAM.

Sagan argued against funding NASA’s Space Shuttle program in favor of more robotic exploration of the farther reaches of space. “That’s not space exploration,” he said in an interview about the space shuttle program’s week-long orbits. “Space exploration is going to other worlds.” A space station would only be worth it, he argued, if it was preparing humans for long-term journeys to space, he told Charlie Rose in 1995.

5. HE WAS AN EARLY CRUSADER AGAINST CLIMATE CHANGE.

Carl Sagan with the other founders of the Planetary Society in the 1970s.
JPL via Wikimedia Commons // Public Domain

Sagan’s 1960 Ph.D. thesis concerned the atmosphere of Venus. His theoretical model showed that the planet’s extremely high surface temperatures were due to the greenhouse effect of an atmosphere filled with carbon dioxide and water vapor. In his book Cosmos, he wrote, “The surface environment of Venus is a warning: something disastrous can happen to a planet rather like our own.”

6. HE HAS AN ARCHIVE IN THE LIBRARY OF CONGRESS ENDOWED BY THE CREATOR OF FAMILY GUY.

Part of the Carl Sagan Papers in the Library of Congress.
Paul Morigi/Getty Images

Family Guy creator Seth McFarlane put up an undisclosed sum to help the Library of Congress buy more than a thousand boxes of material kept by the late scientist and his wife and collaborator, Ann Druyan. The papers in The Seth MacFarlane Collection of Carl Sagan and Ann Druyan Archive, which opened in 2013, include some of Sagan’s earliest notebooks and report cards.

7. HE BECAME FAMOUS FOR A PHRASE HE NEVER SAID.

After Sagan appeared in several successful spots on the Tonight Show Starring Johnny Carson, Carson saw fit to send up the scientist’s signature style (turtleneck included) in a parody sketch.

Carson’s exaggerated use of “billions and billions” would later become associated with the astronomer, though he didn’t use it himself. However, Sagan did talk about large numbers quite a lot, as this supercut shows.

8. HE AND ANN DRUYAN DATED FOR ONE PHONE CALL—AND WERE ENGAGED BEFORE HANGING UP.

Sagan and Druyan, who would create the TV show Cosmos together, fell in love while working on the Voyager message. The courtship was exceedingly brief, as NPR's Radiolab describes:

“After searching endlessly for a piece of Chinese music to put on the record, Druyan had finally found a 2500-year-old song called ‘Flowing Stream.’ In her excitement, she called Sagan and left a message at his hotel. At that point, Druyan and Sagan had been professional acquaintances and friends, but nothing more. But an hour later, when Sagan called back, something happened. By the end of that call, Druyan and Sagan were engaged to be married."

9. HE WANTED TO LEGALIZE POT.

Under the pseudonym “Mr. X,” Sagan wrote a 1969 essay for Time magazine about the personal benefits he’d seen from cannabis use. Then in his mid-30s, he admitted to smoking throughout the prior decade. “I find that today a single joint is enough to get me high,” he wrote, going on to observe that marijuana had enhanced his appreciation for art and music. He concluded that “the illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world.”

10. HE THOUGHT STAR TREK WAS TOO WHITE.

“In a global terrestrial society centuries in the future, the ship’s officers are embarrassingly Anglo-American. In fact, only two of 12 or 14 interstellar vessels are given non-English names, Kongo and Potemkin,” he wrote in a piece about the impact of science fiction on his life in The New York Times in 1978.

11. HE WANTED US TO LEAVE MARS ALONE.

Despite his passion for exploring space, Sagan argued for the preservation of Mars even if it meant limiting our exploration of the planet. In Cosmos, Sagan declared:

“If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes. The existence of an independent biology on a nearby planet is a treasure beyond assessing, and the preservation of that life must, I think, supersede any other possible use of Mars.”

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Space
Here's How to Watch NASA's Livestream Spacewalk Series
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NASA, Wikimedia Commons // Public Domain

Like many Americans, astronauts Randy Bresnik and Mark Vande Hei got up and went to work this morning. But instead of an office, their jobs took them on a walk outside the International Space Station. If that sounds more exciting than what you’re doing at the moment, you can watch their progress live on NASA’s website.

The spacewalk, which commenced the morning of October 5 at 8 a.m. EDT and is expected to last over six hours, is the first of three NASA plans to livestream during the month of October. On this mission, Bresnik, Expedition 53's commander, and Vande Hei, a flight engineer, are replacing one of the motorized lathes on the station’s robotic arm. The Latching End Effectors as they’re called are used to grab cargo vehicles and payloads that arrive at the station.

Bresnik has worked aboard the ISS since July and Vande Hei since September. The pair will don their spacesuits again for NASA’s second livestreamed spacewalk of the month on October 10. On October 18, Bresnik will be leading the third spacewalk and he’ll be assisted by flight engineer Joe Acaba. If you missed this event, you can follow NASA Live for more streams of spacewalks, cargo craft launches, and the occasional orbiter disintegrating in Saturn's atmosphere.

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