J. Zavaleta / NASA

This is a NASA Global Hawk being loaded with monitoring equipment for the ATTREX mission.

By Becky Oskin
Our Amazing Planet

Water may play a critical role in controlling the ozone gas high up in Earth's atmosphere that can act as a greenhouse gas or protect living things on the surface below from the sun's harmful ultraviolet rays, depending on where in the atmosphere it is found.

To better understand how water vapor and ozone interact, NASA plans to send a remote-controlled plane laden with monitoring equipment into the stratosphere — the layer of the atmosphere where protective ozone is found — above the tropics.

The drone will crisscross the tropopause, the boundary between the troposphere (the layer of the atmosphere we breathe and where most weather occurs), and the stratosphere. The boundary is a fluid layer whose thickness can change and depends on the latitude it is located over but that is generally found about 8 to 11 miles (5 to 7 kilometers) above Earth's surface.

In the middle reaches of the troposphere, ozone is a greenhouse gas, trapping heat and contributing to smog. But high in the troposphere and the stratosphere, the familiar ozone layer protects the planet from harmful UV radiation.

When storms punch water vapor through the tropopause, into the stratosphere, scientists suspect chemical reactions between water and free radicals such as chlorine may zap and destroy the protective ozone. The NASA experiment will sample this layer near the equator off the coast of Central America where tall thunderstorms often occur.

The flights, which start this month, are the first of a multiyear campaign to study how changes in water vapor in the stratosphere can affect global climate. The Airborne Tropical Tropopause Experiment (ATTREX) relies on a Global Hawk drone, which can cruise for 30 hours from its home at Edwards Air Force Base in California. The aircraft are also used by the U.S. Air Force and Navy.

Predictions of stratospheric humidity changes are uncertain because of gaps in the understanding of the physical processes occurring in the tropical tropopause layer, NASA said in a statement.

"The ATTREX payload will provide unprecedented measurements of the tropical tropopause," Eric Jensen, ATTREX principal investigator, said in a statement. "This is our first opportunity to sample the tropopause region during winter in the Northern Hemisphere when it is coldest and extremely dry air enters the stratosphere."

Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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A competition that aims to harness the world's most creative engineering minds for building next-generation military drones is heating up with proof-of-flight videos of the contraptions posted online.

There are plenty of quadcopters that will make kids stuck with off-the-shelf RC choppers drool. Top judging in the first round went to a Death Star-like ball on wheels called the GremLion. It's neat trick? A mid-section that pops open to reveal a pair of rotors.

The GremLion was designed by a team at the National University of Singapore and is shown off in the awesomely narrated video above.

However, the video most liked by viewers, as of this writing, demonstrates a tablet-controlled quadcopter called SwiftFlight. The video's production includes Hollywood-esque on-screen pop-up explanations of the action.

Another crowd pleaser is a video describing icarusLabs's entry, a winged aircraft that hovers inside an office before taking to the skies. It buzzes a park with sustained winds of 10 miles per hour, something we know thanks to the detailed reportage.

The next phase of the competition will be live demonstration of the concepts later this month. A fly-off of the 10 top designs will be held this spring. The winner will receive a $100,000 prize, a subcontract with a manufacturer to develop the concept, and an opportunity to demonstrate it to the military. 

For more videos and information on the competition, head on over to UAVforge.net.

— via IEEE

More on drones:

• Future drones may fly like butterflies
• Can drones fly as well as Luke Skywalker?
• U.S. Army orders first suicide drones
• Navy flying drone to launch from submarine's trash chute
• On the wings of technology: Hummingbird drones

John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. You can also follow him on Twitter.

For more of our Future of Technology series, watch the featured video below.

Johns Hopkins University / YouTube

Information on the mechanics of a painted lady butterfly's flight patterns gleaned from high-speed video may be used to construct better designs for military drones.

High-speed video cameras are allowing university researchers to document how butterflies gracefully flutter through the air. The U.S. military funded findings may lead to more agile insect-sized drones sent to spy on enemies.

A key finding is that butterflies appear to use their bodies and wings to twist and turn in the air in a way similar to how ice skaters use their arms to control the speed of their spins, explains Johns Hopkins University undergraduate Tiras Lin, who is working on the high-speed video research.

"Ice skaters who want to spin faster bring their arms in close to their bodies and extend their arms out when they want to slow down," he explains in the video news release below.

"These positions change the spatial distribution of a skater's mass and modify their moment of inertia; this in turn affects the rotation of the skater's body. An insect may be able to do the same thing."

To capture the images of butterflies in flight, Lin used video cameras that record 3,000 one-megapixel images per second. To put that in perspective, a standard video camera shoots 24, 30 or 60 frames per second. "Butterflies flap their wings about 25 times per second," Lin notes.

Most of his analysis zeroed in on 1/5th of a second of flight, or about 600 frames.

Lin recently presented his findings at a meeting of the American Physical Society's Division of Fluid Dynamics. While they haven't yet been adopted by next-generation drones, he said they ought to be. To see how else drones could get buggier in the future, check out the stories below.

More stories on insect-inspired drone technology:

• Biofuel cells may turn cockroaches into cyborgs
• Military developing robot-insect cyborgs
• On wings of technology: Humming bird drones
• Ant-like robots poised to invade the marketplace

Fish and Wildlife Service

Researchers are modeling how birds such as the northern goshawk, shown here, zip through the forest without crashing into trees. Such knowledge could lead to drones that fly fast through cluttered environments.

Next-generation drones may fly like Luke Skywalker zipping through the Endor forest on a speeder bike, suggests new research which focuses on how birds such as northern goshawks determine their maximum speed limit.

These birds race after prey through the forest canopy without smacking into tree trunks.

They avoid this fate by observing a theoretical speed limit, according to scientists at the Massachusetts Institute of Technology.

If researchers can figure out how birds intuit this speed limit, they could use the logic to program drones that race through dense urban cores and other cluttered environments.

State of the art
Most drones today fly at speeds slow enough to stop within the field of view of their sensors. 

"If I can only see up to five meters, I can only go up to a speed that allows me to stop within five meters, which is not very fast," Emilio Frazzoli, an associate professor of aeronautics and astronautics at MIT, said in a news release.

If the northern goshawks were limited by what they could see, they wouldn't fly nearly as fast as they do, he reckons.

Instead the birds likely gauge the density of trees and speed through the forest knowing that given a certain density they can always find an opening.

This is similar to skiers who dive into the trees to find powder. These daredevils maneuver through openings in the forest trusting that they'll keep appearing as they head down the slope. 

As long as the skiers obey their intuited speed limit, they should maintain enough control to avoid obstacles such as partially buried stumps.

Speed limit calculus
Frazzoli and his colleagues used a statistical model of a forest and some tricky math to determine the probability that a bird flying through it at a given speed would crash into a tree.

They found that for any given forest density, there's a critical speed above which there is no "infinite collision-free trajectory," MIT explains.

"If I fly slower than that critical speed, then there is a fair possibility that I will actually be able to fly forever, always avoiding the trees," Frazzoli said in the news release.

In a follow-up email, Frazzoli explained that this finding is non-trivial.

"While it is obvious that the faster one goes, the higher the probability of collision is, it is not obvious that there is a finite 'speed limit' that cannot be exceeded safely," he said.

The research established a theoretical speed limit for any given obstacle-filled environment. Going forward, Frazzoli and colleagues will compare their model results with real-world observations of birds.

They are also creating a video game in which people navigate through a simulated forest at high speeds in order to determine how close humans can come to the theoretical limit.

That sounds a lot like a group of researchers pushing to give real-world drones Luke Skywalker-like abilities.

Updated at 2:00 pm PT

More on drone technology:

• Navy flying drone to launch from submarine's trash chute
• Navy's twin stealth drone takes flight
• On the wings of technology: Hummingbird drones
• Spy plane maneuvers like a bird

A paper detailing the results has been accepted to the IEEE Conference on Robotics and Automation.

John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.