NASA FLEX-2: Jellyfish flames on the ISS

Fire is inanimate, yet anyone staring into a flame could be excused for thinking otherwise: Fire dances and swirls. 

It reproduces, consumes matter, and produces waste. It adapts to its environment. It needs oxygen to survive.

In short, fire is uncannily lifelike.

Nowhere is this more true than onboard a spaceship.

Unlike flames on Earth, which have a tear-drop shape caused by buoyant air rising in a gravitational field, flames in space curl themselves into tiny balls.

Untethered by gravity, they flit around as if they have minds of their own.

More than one astronaut conducting experiments for researchers on Earth below has been struck by the way flameballs roam their test chambers in a lifelike search for oxygen and fuel.

Biologists confirm that fire is not alive. Nevertheless, on August 21st, astronaut Reid Wiseman on the ISS witnessed some of the best mimicry yet.

"It was a jellyfish of fire," he tweeted to Earth along with a video. Wiseman was running an experiment called Flame Extinguishment Experiment 2 (FLEX-2).

The goal of the research is to learn how fires burn in microgravity and, moreover, how to put them out.

It's a basic safety issue: If fire ever breaks out onboard a spacecraft, astronauts need to be able to control it. Understanding the physics of flameballs is crucial to zero-G firefighting.

"Combustion in microgravity is both strange and wonderful," says Forman Williams, the PI of FLEX-2 from UC San Diego.

"The 'jellyfish' phenomenon Wiseman witnessed is a great example."



A new NASA ScienceCast video looks at the lifelike behaviour and underlying physics of jellyfish flames on the ISS.

He points out some of the key elements of the video:

• "Near the beginning we see two needles dispensing a droplet mixture of heptane and iso-octane between two igniters. The fuel is ignited … then the lights go out so we can see what happens next."

• "The flame forms a blue spherical shell 15 to 20 mm in diameter around the fuel. Inside that spherical flame we see some bright yellow hot spots. Those are made of soot."

• Heptane produces a lot of soot as it burns, he explains. Consisting mainly of carbon with a sprinkling of hydrogen, soot burns hot, around 2000 degrees K, and glows brightly as a result.

• "Several globules of burning soot can be seen inside the sphere," he continues. "At one point, a blob of soot punctures the flame-sphere and exits. The soot that exits fades away as it burns out."

There is also an S-shaped object inside the sphere. "That is another soot structure," he says.

The 'jellyfish phase' is closely linked to the production of soot. Combustion products from the spherical flame drift back down onto the fuel droplet.

Because sooty material deposited on the droplet is not perfectly homogeneous, "we can get a disruptive burning event," says Forman.

In other words, soot on the surface of the fuel droplet catches fire, resulting in a lopsided explosion.

Remarkably, none of this is new to Forman, who has been researching combustion physics since the beginning of the Space Age.

"We first saw these disruptive burning events in labs and microgravity drop towers more than 40 years ago," he says.

"The space station is great because the orbiting lab allows us to study them in great detail."

"Tom Avedisian at Cornell is leading this particular study," Forman says. "We're learning about droplet burning rates, the soot production process, and how soot agglomerates inside the flame."

At the end of Wiseman's video, the soot ignites in a final explosion. That's how the fire put itself out.

"It was a warp-drive finish," says Wiseman.

Jellyfish-powered Ornithopter Drone prepares for lift-off - Video

Inspired by nature and by the aviation pioneers of the early 20th century, scientists in the US said Wednesday they had built the world's first jellyfish drone aircraft.

The tiny, ultra-light lab machine, weighing just 2.1 grammes (0.07 ounces), is the first man-made flying object to hover and move with a motion like that of the jellyfish in water, the inventors believe.

Leif Ristroph

"We were interested first of all in making a robotic insect that would be an alternative to the helicopter," said Leif Ristroph, who works alongside Stephen Childress at New York University's Applied Math Lab.

"Our interest ended up being a little bit weird—it was the jellyfish."

The jellyfish has long been admired by engineers for a simple yet efficient motion, sculpted by millions of years of evolution, that requires just a simple muscle and no brain power, just a primitive nervous system.

It has a bell-like translucent skirt that first billows out and then closes tightly, squirting water out from the small opening to provide itself with movement.

In this case, the aircraft uses four petal-shaped wings, each eight centimetres (four inches) long, that when folded together form a downward-facing "cone."

Stephen Childress

A tiny motor, attached to a crankshaft, causes the wings to push outwards and then downwards, 20 times a second, forcing out air through the bottom of the cone.

The result is an "ornithopter," or flying machine that hovers with great stability, without the need for constant, energy-draining correction.

"If it's knocked over, it stabilises by itself," Ristroph said to reporters.

The craft can change direction by making one of the four wings work harder than the others.

Pioneers of flight
The materials to make the machine are all over-the-counter components—light carbon-fibre ribs to hold the motor and provide the frames of the wings, which are covered by transparent Mylar film—bought at ordinary modelling stores.

Ristroph said he and Childress had been intrigued by film footage of aviation pioneers who had tried to mimick insects to build ornithopters, but lacked the knowledge or materials at the time.

More information: Stable hovering of a jellyfish-like flying machine, Journal of the Royal Society Interface, rsif.royalsocietypublishing.org/lookup/doi/10.1098/rsif.2013.0992

Caltech and Harvard Bioengineers Explain Artificial Jellyfish Research - YouTube

Learning from the Jellyfish: Squishy pumps for biomedical and engineering applications

A big goal of our study was to advance tissue engineering,” says Janna Nawroth, a doctoral student in biology at the California Institute of Technology (Caltech) and lead author of the study. “In many ways, it is still a very qualitative art, with people trying to copy a tissue or organ just based on what they think is important or what they see as the major components—without necessarily understanding if those components are relevant to the desired function or without analyzing first how different materials could be used.”

Because a particular function—swimming, say—doesn’t necessarily emerge just from copying every single element of a swimming organism into a design, “our idea,” she says, “was that we would make jellyfish functions—swimming and creating feeding currents—as our target and then build a structure based on that information.”

Their method for building the tissue-engineered jellyfish, dubbed Medusoid, is outlined in a Nature Biotechnology paper.

Robot Jellyfish: Underwater Robots Allow Researchers To Explore Earth’s Final Frontier

Robot jellyfish, an underwater robot inspired by the animal, can power itself with seawater and could potentially be used for rescue missions, military surveillance and environmental monitoring.

Engineers designed the robot jellyfish to use oxygen and hydrogen gases from the ocean water as a renewable energy source to power the underwater robot, researchers said.

Though the robot jellyfish is still a long way from completion, the creation could become the newest tool in the suite of underwater robots scientists use to explore the deep ocean.

Engineered jellyfish definitely have a gee-whiz factor, but underwater robots have already found plenty of uses in research, exploration and resource management.

One of the biggest barriers to underwater exploration is pressure - the further underwater you travel, the more pressure water exerts. Robots allow researchers to survey the deep sea without having to risk travelling down themselves.

The Titanic sank 12,500 feet under the ocean after it hit an iceberg in 1912, a depth where the pressure is over 350 times greater than the surface pressure. In 2010, researchers used two autonomous underwater robots to chart the Titanic's wreck site for the first time.

The robots moved along the ocean floor and took 130,000 pictures of the Titanic's final resting place. Researchers stitched the photos together into the first comprehensive map of the Titanic site. The map and other expedition findings will be released on April 15, 100 years after the ship sank.

Underwater visibility frequently impedes research. Robots can pierce through the darkness or murkiness of the ocean to see things human divers simply cannot, making robots invaluable for rescue missions.

After the devastating earthquake that shook Japan in March 2011, Japan and the United States teamed up and used four suitcase-sized robots to inspect bridges and pipelines and to search for bodies.

Sediment and debris made visibility nearly impossible, so engineers equipped the robots with sonar. The robots fed video to the controllers so researchers could see what the robot saw in real time.

Rescue workers also used an underwater robot to help find a man missing in Moses Lake, Wash. Deputies from the sheriff's office used a robot to examine a reservoir near where a missing man's truck was found, though to no avail. It was the second time the sheriff's office used the robot.

A few weeks earlier, the department used the robot to investigate a submerged truck. The robot was able to help police determine that the truck was empty without any officers having to venture into the frigid water themselves, according to the Tri-City Herald.

Underwater robots aren't just making discoveries and rescue missions however. They are also being used to get kids and adults more interested in science.

The National Underwater Robotics Challenge, held every year since 2007 in Chandler, Ariz., gives kids an opportunity to build a robot of their own to compete in an underwater obstacle course.

"The mission of the National Underwater Robotics Challenge is to bring science and technology educational opportunities to the students of all ages across the country," according to the competition website. "This event is designed to stimulate the youth of America and to reverse the national 'brain drain.'"

Despite the novel technology available and the massive amount of research conducted, much of the ocean is still an enigma.

"We have better maps of the surface of Mars and the moon than we do the bottom of the ocean," Gene Feldman, an oceanographer with NASA's Goddard Space Flight Center, said in a 2009 statement. "In many ways, it's easier to put a person into space than it is to send a person down to the bottom of the ocean."

However, curiosity, coupled with ever-improving technology, may allow researchers to someday study the hard-to-reach places underwater, he said.

Fried Egg Jellyfish: Phacellophora camtschatica

This may look like a fried or poached egg floating in water, but it is in fact a fried egg jellyfish (Phacellophora camtschatica).

A batch of the unusual creatures - which are normally found in the Mediterranean - have been born at the Basel Zoo in Switzerland

Jellyfish; The Spoons of the Sea

When to the new eyes of thee
All things by immortal power,
Near or far,
Hiddenly
To each other linked are,
So that thou canst not stir a flower
Without troubling a star...........

(Francis Thompson)

NEXT time you go for a dip in the sea, bear in mind that your deft front crawl is helping to mix up the waters. In fact, marine life may be stirring the oceans and moving nutrients around as much as winds or tides.

According to a theory proposed by Darwin's grandson, Charles Galton Darwin, a body moving through water drags some of the fluid with it.

Darwin's Drift

In "Darwin drift", a high-pressure zone forms at the front of each swimming animal, leaving an area of lower pressure behind, which draws in adjacent water. This results in a net movement of fluid in the direction of the swimmer.

Swarms of Jellyfish

To test the idea, Kakani Katija and John Dabiri at the California Institute of Technology in Pasadena went to a lake in the Republic of Palau in the Pacific Ocean. Diving among swarms of jellyfish, the pair used suspended dyes and a newly designed laser velocimeter to measure the movement of water around the jellyfish. They found that the animals did indeed drag water with them as they swam (Nature, vol 460, p 624).

Mixing Energy

The researchers then estimated the total energy that all ocean swimmers impart on the water. They calculated that it was on a par with the mixing energy imparted by winds or tides. The findings suggest ocean swimmers can move water over long distances and that they could help run the vertical currents that push nutrients around between the sea floor and surface waters.