Showing posts with label Hydrogen. Show all posts
Showing posts with label Hydrogen. Show all posts

Thursday, October 16, 2014

NASA MAVEN Mars Probe Beams Home First Results

MAVEN spacecraft orbits Mars in this artist's illustration. Image released Oct. 14, 2014. 

Credit: University of Colorado/NASA

NASA's MAVEN Mars orbiter has been busy since it arrived at the Red Planet late last month.

NASA's Mars Atmosphere and Volatile EvolutioN mission (MAVEN) is designed to probe Mars' thin atmosphere, to help scientists understand what caused the planet to change from a warm, wet world long ago to the cold and dry one it is today. 

The spacecraft entered into orbit around Mars on Sept. 21, and it has already beamed back some amazing new data about Mars' upper atmosphere, researchers said.

In MAVEN's first few weeks of instrument testing at the Red Planet, scientists have already created some of the most complete maps of atomic hydrogen, oxygen, carbon and ozone in the Martian atmosphere ever made. 

One of MAVEN's instruments even collected data as energetic particles blasted out by a massive solar eruption made it to Mars. 


MAVEN is still in the "commissioning phase" of its mission, meaning that the probe hasn't started collecting science full-time. 

The new data were gathered as the spacecraft's ground controllers began turning on its instruments after it arrived at Mars.


This graph shows atomic hydrogen scattering ultraviolet sunlight in the upper atmosphere of Mars, with data obtained by MAVEN’s Imaging Ultraviolet Spectrograph. 

Credit: University of Colorado, NASA


Scientists working with MAVEN weren't able to see exactly how the solar energetic particles (SEPs) affected Mars' atmosphere on Sept. 29 because the instruments necessary for that kind of observation weren't functioning in tandem at that time. 

MAVEN researchers expect, however, that the spacecraft's instruments will be ready to observe the atmosphere during the next Mars-directed solar event.

"After traveling through interplanetary space, these energetic particles of mostly protons deposit their energy in the upper atmosphere of Mars," SEP instrument lead Davin Larson, of the University of California, Berkeley's Space Sciences Laboratory, said in a statement

"An SEP event like this typically occurs every couple weeks. Once all the instruments are turned on, we expect to also be able to track the response of the upper atmosphere to them."
This image shows atomic carbon scattering ultraviolet sunlight in the upper atmosphere of Mars, as observed by MAVEN’s Imaging Ultraviolet Spectrograph. A red circle indicates Mars. Sunlight illuminates the planet from the right.

Credit: University of Colorado; NASA

This image shows atomic oxygen scattering ultraviolet sunlight in the upper atmosphere of Mars, as observed by MAVEN’s Imaging Ultraviolet Spectrograph. 

Most oxygen appears trapped near the planet, marked by the red circle.

Credit: University of Colorado; NASA


Tuesday, July 29, 2014

Silicon-capped hydrocarbons: Mysterious molecules in space

This graph shows absorption wavelength as a function of the number of carbon atoms in the silicon-terminated carbon chains SiC_(2n+1)H, for the extremely strong pi-pi electronic transitions. 

When the chain contains 13 or more carbon atoms, not significantly longer than carbon chains already known to exist in space, these strong transitions overlap with the spectral region occupied by the elusive diffuse interstellar bands. 

Credit: D. Kokkin, ASU

Over the vast, empty reaches of interstellar space, countless small molecules tumble quietly though the cold vacuum.

Forged in the fusion furnaces of ancient stars and ejected into space when those stars exploded, these lonely molecules account for a significant amount of all the carbon, hydrogen, silicon and other atoms in the universe.

In fact, some 20 percent of all the carbon in the universe is thought to exist as some form of interstellar molecule.

Many astronomers hypothesize that these interstellar molecules are also responsible for an observed phenomenon on Earth known as the "diffuse interstellar bands," spectrographic proof that something out there in the universe is absorbing certain distinct colours of light from stars before it reaches the Earth.

But since we don't know the exact chemical composition and atomic arrangements of these mysterious molecules, it remains unproven whether they are, in fact, responsible for the diffuse interstellar bands.

Now in a paper appearing this week in The Journal of Chemical Physics, from AIP Publishing, a group of scientists led by researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. has offered a tantalising new possibility: these mysterious molecules may be silicon-capped hydrocarbons like SiC3H, SiC4H and SiC5H, and they present data and theoretical arguments to back that hypothesis.

At the same time, the group cautions that history has shown that while many possibilities have been proposed as the source of diffuse interstellar bands, none has been proven definitively.

"There have been a number of explanations over the years, and they cover the gamut," said Michael McCarthy a senior physicist at the Harvard-Smithsonian Center for Astrophysics (CfA) who led the study.

Molecules in Space and How We Know They're There
Astronomers have long known that interstellar molecules containing carbon atoms exist and that by their nature they will absorb light shining on them from stars and other luminous bodies.

Because of this, a number of scientists have previously proposed that some type of interstellar molecules are the source of diffuse interstellar bands, the hundreds of dark absorption lines seen in color spectrograms taken from Earth.

In showing nothing, these dark bands reveal everything. The missing colours correspond to photons of given wavelengths that were absorbed as they travelled through the vast reaches of space before reaching us.

More than that, if these photons were filtered by falling on space-based molecules, the wavelengths reveal the exact energies it took to excite the electronic structures of those absorbing molecules in a defined way.

Armed with that information, scientists here on Earth should be able to use spectroscopy to identify those interstellar molecules, by demonstrating which molecules in the laboratory have the same absorptive "fingerprints."

But despite decades of effort, the identity of the molecules that account for the diffuse interstellar bands remains a mystery.

Nobody has been able to reproduce the exact same absorption spectra in laboratories here on Earth.

"Not a single one has been definitively assigned to a specific molecule," said Neil Reilly, a former postdoctoral fellow at Harvard-Smithsonian Center for Astrophysics (CfA) and a co-author of the new paper.

Now Reilly, McCarthy and their colleagues are pointing to an unusual set of molecules, silicon-terminated carbon chain radicals, as a possible source of these mysterious bands.

As they report in their new paper, the team first created silicon-containing carbon chains SiC3H, SiC4H and SiC5H in the laboratory using a jet-cooled silane-acetylene discharge.

They then analysed their spectra and carried out theoretical calculations to predict that longer chains in this family might account for some portion of the diffuse interstellar bands.

However, McCarthy cautioned that the work has not yet revealed the smoking gun source of the diffuse interstellar bands.

To prove that these larger silicon capped hydrocarbon molecules are such a source, more work needs to be done in the laboratory to define the exact types of transitions these molecules undergo, and these would have to be directly related to astronomical observations.

But the study provides a tantalising possibility for finding the elusive source of some of the mystery absorption bands, and it reveals more of the rich molecular diversity of space.

"The interstellar medium is a fascinating environment," McCarthy said. "Many of the things that are quite abundant there are really unknown on Earth."

More information: The Journal of Chemical Physics, July 29, 2014. DOI: 10.1063/1.4883521

Thursday, May 30, 2013

Mars Life: Water-rock reaction may provide enough hydrogen 'food'

A chemical reaction between iron-containing minerals and water may produce enough hydrogen "food" to sustain microbial communities living in pores and cracks within the enormous volume of rock below the ocean floor and parts of the continents, according to a new study led by the University of Colorado Boulder.

The findings, published in the journal Nature Geoscience, also hint at the possibility that hydrogen-dependent life could have existed where iron-rich igneous rocks on Mars were once in contact with water.

Scientists have thoroughly investigated how rock-water reactions can produce hydrogen in places where the temperatures are far too hot for living things to survive, such as in the rocks that underlie hydrothermal vent systems on the floor of the Atlantic Ocean.

The hydrogen gases produced in those rocks do eventually feed microbial life, but the communities are located only in small, cooler oases where the vent fluids mix with seawater.

Lisa Mayhew
The new study, led by CU-Boulder Research Associate Lisa Mayhew, set out to investigate whether hydrogen-producing reactions also could take place in the much more abundant rocks that are infiltrated with water at temperatures cool enough for life to survive.

Alexis Templeton
"Water-rock reactions that produce hydrogen gas are thought to have been one of the earliest sources of energy for life on Earth," said Mayhew, who worked on the study as a doctoral student in CU-Boulder Associate Professor Alexis Templeton's lab in the Department of Geological Sciences.

"However, we know very little about the possibility that hydrogen will be produced from these reactions when the temperatures are low enough that life can survive."

"If these reactions could make enough hydrogen at these low temperatures, then microorganisms might be able to live in the rocks where this reaction occurs, which could potentially be a huge subsurface microbial habitat for hydrogen-utilizing life."

When igneous rocks, which form when magma slowly cools deep within the Earth, are infiltrated by ocean water, some of the minerals release unstable atoms of iron into the water.

At high temperatures—warmer than 392 degrees Fahrenheit—scientists know that the unstable atoms, known as reduced iron, can rapidly split water molecules and produce hydrogen gas, as well as new minerals containing iron in the more stable, oxidized form.

More information here

Sunday, May 12, 2013

Ion Tiger sets New Endurance Record for Small Electric Unmanned Aerial Vehicles

Fueled by liquid hydrogen (LH2), the Ion Tiger unmanned aerial vehicle (UAV) completes a record flight time of 48 hours and 1 minute. 

The electric fuel cell propulsion system onboard the Ion Tiger has the low noise and signature of a battery-powered UAV, while taking advantage of high-energy hydrogen fuel and the high electric efficiency of fuel cells. 

Credit: Image courtesy of Naval Research Laboratory (NRL)

Researchers at the U.S. Naval Research Laboratory flew their fuel cell powered Ion Tiger UAV for 48 hours and 1 minute on April 16-18 by using liquid hydrogen fuel in a new, NRL-developed, cryogenic fuel storage tank and delivery system.

This flight shatters their previous record of 26 hours and 2 minutes set in 2009 using the same vehicle, but with gaseous hydrogen stored at 5000 psi.

Liquid hydrogen is three times denser than 5000-psi compressed hydrogen. The cryogenic liquid is stored in a lightweight tank, allowing more hydrogen to be carried onboard to increase flight endurance.

Success in flight requires developing a high quality, lightweight insulated flight dewar for the cryogenic fuel, plus matching the boil off of the cryogenic hydrogen to the vehicle fuel consumption.

"Liquid hydrogen coupled with fuel-cell technology has the potential to expand the utility of small unmanned systems by greatly increasing endurance while still affording all the benefits of electric propulsion," said Dr. Karen Swider-Lyons, NRL principal investigator.

Although long endurance is possible with conventional, hydrocarbon-fueled systems, these are usually loud, inefficient, and unreliable in this aircraft class.

Similarly, small, electric, battery-powered systems are limited to endurances of only several hours.

To address the logistics of in-theater supply of liquid or gaseous hydrogen, NRL proposes in-situ manufacture of LH2 for use as fuel.

An electrolyzer-based system would require only water for feedstock, and electricity, possibly from solar or wind, to electrolyze, compress, and refrigerate the fuel.

The NRL LH2 flight capability is being developed by NRL's Tactical Electronic Warfare and Chemistry Divisions, and is sponsored by the Office of Naval Research.

Wednesday, August 15, 2012

Lunar Reconnaissance Orbiter spectrometer detects helium in Moon's atmosphere

The Lyman Alpha Mapping Project (LAMP) aboard LRO (shown here in a pre-flight photo) uses a novel method to peer into the perpetual darkness of the moon's so-called permanently shadowed regions.

LAMP "sees" the lunar surface using the ultraviolet light from nearby space and stars, which bathes all bodies in space in a soft glow of ultraviolet light. (Credit: NASA Goddard/Debbie McCallum)

Geophysical Research Letters, Vol. 39, doi:10.1029/2012GL051797 , 2012.

Scientists using the Lyman Alpha Mapping Project (LAMP) aboard NASA's Lunar Reconnaissance Orbiter have made the first spectroscopic observations of the noble gas helium in the tenuous atmosphere surrounding the Moon.

These remote-sensing observations complement in-situ measurements taken in 1972 by the Lunar Atmosphere Composition Experiment (LACE) deployed by Apollo 17.

Although LAMP was designed to map the lunar surface, the team expanded its science investigation to examine the far ultraviolet emissions visible in the tenuous atmosphere above the lunar surface, detecting helium over a campaign spanning more than 50 orbits.

Because helium also resides in the interplanetary background, several techniques were applied to remove signal contributions from the background helium and determine the amount of helium native to the Moon.

Geophysical Research Letters published a paper on this research in 2012. "The question now becomes, does the helium originate from inside the Moon, for example, due to radioactive decay in rocks, or from an exterior source, such as the solar wind?" says Dr. Alan Stern, LAMP principal investigator and associate vice president of the Space Science and Engineering Division at Southwest Research Institute.

With support from LRO's suite of instruments, LAMP has previously determined that hydrogen, mercury and other volatile substances are present in the permanently shaded regions (PSRs) of the moon.

It has also observed PSRs are darker at far-ultraviolet wavelengths and redder than nearby surfaces that receive sunlight.

These darker regions indicate "fluffy" soils, while the reddening is consistent with the presence of water frost.

In a related study led by Dr. Paul Feldman of Johns Hopkins University and published in Icarus, observations showed day-to-day variations in helium abundances, possibly varying with the solar wind, and also significantly decreasing when the Moon passed behind Earth out of sight from the solar wind.

"If we find the solar wind is responsible, that will teach us a lot about how the same process works in other airless bodies," says Stern.

 If spacecraft observations show no such correlation, radioactive decay or other internal lunar processes could be producing helium that diffuses from the interior or that releases during lunar quakes.

Wednesday, May 2, 2012

Hubble Archive Image: Old star reveals Arsenic and Selenium

An ultraviolet spectrum taken from the Hubble Space Telescope public archives revealed arsenic and selenium in a 12 billion year-old halo star dubbed HD 160617.

"Arsenic and selenium elements were forged in an even older star, which has long since disappeared, and then-like genes passed on from parent to infant-they were born into the star we see today, HD 160617." reported Ian Roederer, along with co-author James Lawler.

The Big Bang produced lots of hydrogen and helium and a smidgen of lithium.

All heavier elements found on the periodic table have been produced by stars over the last 13.7 billion years. Astronomers analyze starlight to determine the chemical makeup of stars, the origin of the elements, the ages of stars, and the evolution of galaxies and the universe.

Now for the first time, astronomers have detected the presence of arsenic and selenium, neighbouring elements near the middle of the periodic table, in an ancient star in the faint stellar halo that surrounds the Milky Way.

Arsenic and selenium are elements at the transition from light to heavy element production, and have not been found in old stars until now.

Lead author of the Astrophysical Journal paper, Fellow Ian Roederer of the Carnegie Observatories explained: "Stars like our Sun can make elements up to oxygen on the periodic table. Other more massive stars can synthesize heavier elements, those with more protons in their nuclei, up to iron by nuclear fusion-the process in which atomic nuclei fuse and release lots of energy. Most of the elements heavier than iron are made by a process called neutron-capture nucleosynthesis."

"Although neutrons have no charge, they can decay into protons after they're in the nucleus, producing elements with larger atomic numbers. One of the ways that this method can work is by exposure to a burst of neutrons during the violent supernova death of a star."

"We call this process the rapid process (r-process). It can produce elements at the middle and bottom of the periodic table-from zinc to uranium-in the blink of an eye."

Roederer, with co-author James Lawler, looked at an ultraviolet spectrum from the Hubble Space Telescope public archives to find arsenic and selenium in a 12 billion year-old halo star dubbed HD 160617.

"These elements were forged in an even older star, which has long since disappeared, and then-like genes passed on from parent to infant-they were born into the star we see today, HD 160617."

The team also examined data for this star from the public archives of several ground-based telescopes and were able to detect 45 elements. In addition to arsenic and selenium, they found rarely seen cadmium, tellurium, and platinum, all of which were produced by the r-process.

This is the first time these elements have been detected together outside the Solar System. Astronomers cannot replicate the r-process in any laboratory since the conditions are so extreme. The key to modeling the r-process relies on astronomical observations.

"What I find exciting is that arsenic and selenium can be found in other stars, even ones like HD 160617 that we've been studying for decades," remarked Roederer.

"Now that we know where to look, we can go back and study these elements in other stars. Understanding the r-process helps us know why we find certain elements like barium on Earth, or understand why uranium is so rare."

Thursday, April 19, 2012

Probing hydrogen under extreme conditions

How hydrogen--the most abundant element in the cosmos--responds to extremes of pressure and temperature is one of the major challenges in modern physical science.

Moreover, knowledge gleaned from experiments using hydrogen as a testing ground on the nature of chemical bonding can fundamentally expand our understanding of matter.

New work from Carnegie scientists has enabled researchers to examine hydrogen under pressures never before possible. Their work is published online in Physical Review Letters.

To explore hydrogen in this new domain, the scientists developed new techniques to contain hydrogen at pressures of nearly 3 million times normal atmospheric pressure (300 Gigapascals) and to probe its bonding and electronic properties with infrared radiation. They used a facility that Carnegie manages and operates at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory in partnership with NSLS.

Observing hydrogen's behavior under very high pressures has been a great challenge for researchers, because it is in a gas state under normal conditions. It is known that it has three solid molecular phases. But the structures and properties of highest-pressure phases are unknown.

For example, a transition to a phase that occurs at about 1.5 million times atmospheric pressure (150 Gigapascals) and at low temperatures has been of particular interest. But there have been technological hurdles in examining hydrogen at much higher pressures using static compression techniques.

It has been speculated that under at high pressures, hydrogen transforms to a metal, which means it conducts electricity. It could even become a superconductor or a superfluid that never freezes--a completely new and exotic state of matter.

Wednesday, April 18, 2012

H3+: The Molecule that Made the Universe


The molecule known as H3+ is believed to have had a vital role in cooling down the first stars of the universe, and may still play an important part in the formation of current stars. Above, new stars burst into being in the star-forming nebula Messier 78, imaged by NASA's Spitzer Space Telescope. (Image credit: NASA/JPL-Caltech)

In a study that pushed quantum mechanical theory and research capabilities to the limit, UA researchers have found a way to see the molecule that likely made the universe - or at least the hot and fiery bits of it.

Lurking in the vast, chilly regions between stars, the unassuming molecule known as a triatomic hydrogen ion, or H3+, may hold secrets of the formation of the first stars after the Big Bang.

At the University of Arizona, then doctoral candidate Michele Pavanello spent months doing painstaking calculations to find a way to spot H3+ and unveil its pivotal role in astronomy and spectroscopy, supervised by Ludwik Adamowicz, a professor in the UA's department of chemistry and biochemistry.

The groundbreaking results have been published in a recent edition of Physical Review Letters.

"Most of the universe consists of hydrogen in various forms," said Adamowicz, "but the H3+ ion is the most prevalent molecular ion in interstellar space. It's also one of the most important molecules in existence."

Believed to be critical to the formation of stars in the early days of the universe, H3+ also is the precursor to many types of chemical reactions, said Adamowicz, including those leading to compounds such as water or carbon, which are essential for life.

Early stars would have become hotter and hotter until they exploded before they ever formed, according to Pavanello, unless there was a way to release some of that pent-up energy.

"There wouldn't be any star formation if there weren't molecules that slowly cool down the forming star by emitting light," said Pavanello. Not many molecules can do that, he added, partly because very few molecules existed in the early days of the universe.

"Astronomers think that the only molecule that could cool down a forming star in that particular time is H3+."

A perfect asymmetry
Another molecule, molecular hydrogen, would have been present, but it would have had a much harder time cooling a forming star than H3+. "Hydrogen does not like to emit light, while H3+ can bend and vibrate, and in doing so it is able to emit light." said Pavanello.

H3+ is an electrically charged molecule, called an ion. It consists of three hydrogen atoms with only two, as opposed to a healthy three, electrons to share between them. Lacking a negatively charged electron, the molecule takes on a plus-one positive charge.

H3+ has a triangular shape, explained Adamowicz. "As it is excited it starts to vibrate in various ways."

"One has to involve a large amount of computations at the quantum mechanical level to predict those vibrations," said Adamowicz. "The role of theory is essentially to simulate those vibrations in the computer and then describe how the molecule is swinging or dancing."

Understanding the various vibrations of H3+ could help astronomers deduce to what extent it played a role in the formation of the early stars.

"In the 1990s, H3+ was observed surrounding stars," said Adamowicz. "The stars emit radiation, which not only contributes to the production of H3+ but also excites the molecule to higher energy states. The molecule can also become excited through leftover energy from chemical reactions it was involved in or through collisions with other molecules. In the process of de-excitation the molecule emits photons that are detected by our radio telescopes."

"That can only happen with H3+ because molecular hydrogen is too symmetric," said Pavanello. "And so H3+ has a very important cooling function in the formation of the first stars after the Big Bang."

"The only way we can predict how the stars form is if we know very well what the cooling abilities of H3+ are, and we cannot know its cooling ability until we know its vibrational spectrum. We need to know what these energy levels are," said Pavanello.

"With this paper we have pinpointed the energy levels up to a certain energy threshold that is already good enough to generate accurate predictions of the cooling ability of H3+," said Pavanello.

It happened almost by chance
The group didn't set out to unlock the secrets of H3+, said Pavanello, who graduated from the UA in 2010 with a prestigious Marie Curie post-doctoral fellowship that took him to Leiden University in the Netherlands. He is now an assistant professor of theoretical chemistry at Rutgers University in Newark, N.J.

"It all happened almost by chance," he said. "A friend of the mass-spectrometry facility in the UA's chemistry department happens to be a very good quantum chemist from Hungary. He once visited the department and talked to Ludwik about the possibility to do some H3+ calculations. At the time, I had just started. The code I was writing was almost done, and we thought H3+ could be a good system on which to test this code."

The researchers input a computer code into super computers at the UA's High Performance Computing Center that described the ways in which H3+ vibrates according to quantum mechanical principles. "We couldn't have done this without their support," said Pavanello.

Depending on the level of approximations made in the computer code, said Pavanello, the researchers can develop software that can describe the motion of small molecules very well, or large molecules very approximately.

"We decided to implement something that had essentially no approximations, but of course with the price that we can only apply it to very small molecules," said Pavanello. "Our method simply did not exist before in a mainstream form."

The UA team's results were corroborated by teams from Hungary, France, London and Russia, and also by experiments done at the Max-Planck Institute in Heidelberg, Germany that created H3+ in a laboratory and verified that its spectral lines matched the predictions.

The UA team's contribution allowed the researchers for the first time to assign spectral lines of H3+ to particular types of the vibrational motions as the ion releases photons with near-visible wavelengths. These wavelengths contribute to the color of the light H3+ radiates toward us from interstellar space.

Tuesday, December 27, 2011

NASA Chandra X-ray Image: Ring of Fire

This composite image shows the central region of the spiral galaxy NGC 4151.

X-rays (blue) from the Chandra X-ray Observatory are combined with optical data (yellow) showing positively charged hydrogen (H II) from observations with the 1-meter Jacobus Kapteyn Telescope on La Palma.

The red ring shows neutral hydrogen detected by radio observations with the NSF's Very Large Array.

This neutral hydrogen is part of a structure near the center of NGC 4151 that has been distorted by gravitational interactions with the rest of the galaxy, and includes material falling towards the center of the galaxy.

The yellow blobs around the red ellipse are regions where star formation has recently occurred.

A recent study shows the X-ray emission probably was caused by an outburst powered by the supermassive black hole located in the white region in the center of the galaxy. Evidence for this idea comes from the elongation of the X-rays running from the top left to the bottom right and details of the X-ray spectrum.

There are also signs of interactions between a central source and the surrounding gas, particularly the yellow arc of H II emission located above and to the left of the black hole.

NGC 4151 is located about 43 million light years away from the Earth and is one of the nearest galaxies that contains an actively growing black hole. Because of this proximity, it offers one of the best chances of studying the interaction between an active supermassive black hole and the surrounding gas of its host galaxy.

Such interaction, or feedback, is recognized to play a key role in the growth of supermassive black holes and their host galaxies. If the X-ray emission in NGC 4151 originates from hot gas heated by the outflow from the central black hole, it would be strong evidence for feedback from active black holes to the surrounding gas on galaxy scales.

This would resemble the larger scale feedback, observed on galaxy cluster scales, from active black holes interacting with the surrounding gas, as seen in objects like the Perseus Cluster.

Image Credits: X-ray: NASA/CXC/CfA/J.Wang et al.; Optical: Isaac Newton Group of Telescopes, La Palma/Jacobus Kapteyn Telescope, Radio: NSF/NRAO/VLA

Tuesday, November 29, 2011

ESA prepares new technologies for future launchers

ESA and the DLR German Space Center fired a Texus rocket 263 km into space on 27 November to test a new way of handling propellants on Europe’s future rockets.

Texus 48 lifted off at 10:10 GMT (11:10 CET) from the Esrange Space Centre near Kiruna in northern Sweden on its 13-minute flight.

During the six minutes of weightlessness – mimicking the different stages of a full spaceflight – two new devices were tested for handling super-cold liquid hydrogen and oxygen propellants and then recovered for analysis.

Building on over 30 years of Texus missions, flight 48 was the first to demonstrate a new technology for future launchers.

DLR procured the rocket for this flight, which was performed under ESA’s Cryogenic Upper Stage Technologies (CUST) project as part of the Future Launchers Preparatory Programme (FLPP).

ESA Portal - Europe prepares new technologies for future launchers

Improved upper stage
ESA is working on a restartable cryogenic upper stage to improve Europe’s launchers.

Liquids naturally float around in weightlessness but to ensure engine ignition after a long coast in low-gravity, propellant must be held ready at the tank’s outlet using ‘capillary’ forces – the same force that helps paper towels soak up water.

Although this has already been mastered for launchers and satellites that use storable liquids, higher-performance cryogenic fluids are more difficult to handle.

On Texus 48, liquid nitrogen represented the cryogenic propellants to ease cost and safety constraints, and simplify the thermal design.

“The launch of Texus 48 demonstrating new technologies for future rockets was a success. It also shows great cooperation with DLR, where joint efforts made this flight possible on time,” said Guy Pilchen, Future Launchers Preparatory Programme Manager.

Friday, October 14, 2011

The Hazy History of Titan's Air

What rocky moon has a nitrogen-rich atmosphere, Earth-like weather patterns and geology, liquid hydrocarbon seas and a relatively good chance to support life?

The answer is Titan, the fascinating moon of Saturn.

Titan's many similarities to Earth is why astrobiologists are so fascinated by this unusual moon.

Its atmosphere is often viewed as an analog to what the Earth's atmosphere may have been like billions of years ago.

Despite the 800 million miles between the two worlds, both may have had their atmospheres created through the gravitational layering and processing of asteroids and comets.

"Titan provides an extraordinary environment to better understand some of the chemical processes that led to the appearance of life on Earth," says Josep M. Trigo-Rodriguez, of the Institute of Space Sciences (CSIC-IEEC) in Barcelona, Spain.

"Titan's atmosphere is a natural laboratory that, in many aspects, seems to have a strong similitude with our current picture of the pre-biotic atmosphere of Earth."

This is remarkable, because it was thought that Earth and Titan were made from a vastly different recipe of materials in drastically different temperatures, he says.

The research paper, "Clues on the importance of comets in the origin and evolution of the atmospheres of Titan," by Trigo-Rodriguez and F. Javier Martin-Torres (Center for Astrobiology, Madrid, Spain), recently published in the journal Planetary and Space Science, offers insight into the atmospheric affinities of Earth and Titan.


Building an Atmosphere From Scratch
Earth presumably formed from scorched, oxygen-poor rocks (planetesimals) located in the inner solar system, while Titan formed from rocks that were rich in oxygen and other volatile chemicals (cometesimals) in the outer solar system.

Trigo-Rodriguez and Martin-Torres believe the vital organic ingredients in the early Earth's atmosphere were vaporized and swept away by solar winds.

The ingredients for the air we breathe today returned about 4 billion years ago, during a cataclysmic rock storm known as the Late Heavy Bombardment (LHB). During this period, oxygen- and volatile-rich materials from the outer solar system were hurled en masse towards the inner solar system.

Chris McKay, a planetary scientist at NASA's Ames Research Center, says comets may have made small contributions to the water, carbon dioxide, and nitrogen content of the Earth's early atmosphere, "but they were not the main source."

This is known because the Deuterium/Hydrogen ratios of our oceans do not match the ratios found in comets. He says asteroids hurled our way during the LHB could be the main source of water on Earth.

Trigo-Rodriguez says he and McKay are basically on the same page. "We think that asteroids and comets were key sources for water and organics," says Trigo-Rodriguez. Four billion years ago, some asteroids contained so much ice that they would have brought just as much water to our planet as comets did.

Trigo-Rodriguez and Martin Torres studied how hydrogen, carbon, nitrogen and oxygen isotopes reacted with their environments on Earth and Titan. They looked at data recorded by the Cassini-Huygens probe to better understand the isotopic ratios in Titan's dense, hazy atmosphere.

Different distances from the Sun, different sizes and different environmental conditions led to different chemical evolutions on the two worlds. Even so, both Earth and Titan were hit by similar water-rich bodies, which provided a volatile-rich source for both atmospheres during the late-heavy bombardment.

Outgassing and collisional processing on both worlds led to the production of molecular nitrogen-dominated atmospheres with similar isotopic ratios of hydrogen, carbon, nitrogen and oxygen.

Wednesday, September 21, 2011

ESA ESO: Chicken space dust cloud

With bright glowing eyes and a swirl of crimson, the chicken concealed in the Lambda Centauri nebula looks ready to pummel some pigs in a game of Angry Birds.

The new shot from the European Southern Observatory shows hot newborn stars that formed from hydrogen gas clouds glowing brightly with ultraviolet light.

The intense radiation excites the hydrogen cloud, making it glow red.

Visible against the red clouds, black clumps called Bok globules dot the frame and conceal stars within.

Known playfully as the "running chicken" nebula, the bird's roost is some 6500 light years from Earth in the constellation Centaurus. But where does the chicken end? If you think you can make out its exact outline, submit your guess to the observatory's Flickr group for a chance at a prize.

Wednesday, August 10, 2011

A Freaky Fluid inside Jupiter

"Liquid metallic hydrogen has low viscosity, like water, and it's a good electrical and thermal conductor," says Caltech's David Stevenson, an expert in planet formation, evolution, and structure.

Last Friday, August 5th, NASA's Juno spacecraft blasted off on a 5-year voyage to a freakish world: planet Jupiter.

Jupiter has a long list of oddities. For one thing, it's enormous, containing 70% of our solar system's planetary material, yet it is not like the rocky world beneath our feet. Jupiter is so gassy, it seems more like a star.

Jupiter's atmosphere brews hurricanes twice as wide as Earth itself, monsters that generate 400 mph winds and lightning 100 times brighter than terrestrial bolts. The giant planet also emits a brand of radiation lethal to unprotected humans.

Jupiter's strangest feature, however, may be a 25,000 mile deep soup of exotic fluid sloshing around its interior. It's called liquid metallic hydrogen.

"Here on Earth, hydrogen is a colorless, transparent gas," says Juno principal investigator Scott Bolton. "But in the core of Jupiter, hydrogen transforms into something bizarre."

Jupiter is 90% hydrogen1, with 10% helium and a sprinkle of all the other elements. In the gas giant's outer layers, hydrogen is a gas just like on Earth.

As you go deeper, intense atmospheric pressure gradually turns the gas into a dense fluid.2 Eventually the pressure becomes so great that it squeezes the electrons out of the hydrogen atoms and the fluid starts to conduct like a metal.

What's this fluid like?

"Liquid metallic hydrogen has low viscosity, like water, and it's a good electrical and thermal conductor," says Caltech's David Stevenson, an expert in planet formation, evolution, and structure.

"Like a mirror, it reflects light, so if you were immersed in it [here's hoping you never are], you wouldn't be able to see anything."

Here on Earth, liquid metallic hydrogen has been made in shock wave experiments, but since it doesn't stay in that form it has only been made in tiny quantities for very short periods of time. If researchers are right, Jupiter's core may be filled with oceans of the stuff.

There's so much LMH inside Jupiter that it transforms the planet into an enormous generator. "A deep layer of liquid metallic hydrogen and Jupiter's rapid rotation (about 10 hours) create a magnetic field 450 million miles long - the biggest entity in the solar system," says Bolton.

Jupiter's magnetosphere can produce up to 10 million amps of electric current, with auroras that light up Jupiter's poles more brightly than any other planet.

Although scientists are fairly sure that liquid metallic hydrogen exists inside Jupiter, they don't know exactly how the big planet's interior is structured. For instance, where does the hydrogen turn into a conductor? Does Jupiter have a core of heavy elements inside?

Juno's mission is to answer those key questions.

Tuesday, October 19, 2010

Festo Air Penquins - Bionic Fin Ray® structure




A group of three autonomously flying penguins hovers freely through a defined air space that is monitored by ultrasound transmission stations. The penguins are at liberty to move within this space; a microcontroller gives them free will in order to explore it.

The bionic Fin Ray® structure, derived from the anatomy of a fish's fin, was extended here for the first time to applications in three-dimensional space.

If the 3D Fin Ray® structure of the head and tail sections is transferred to the requirements of automation technology, it can be used for instance in a flexible tripod with a very large scope of operation in comparison with conventional tripods.

Tuesday, July 27, 2010

Waste chip fat fuels hydrogen economy

Don’t pour that dirty fat from the frier down the sink — it could be used to make the fuel of the future.

Hydrogen has been tipped as a cleaner, greener alternative to fossil fuels. But scientists have struggled to find a way to make it that doesn’t consume vast amounts of energy, use up scarce natural resources, or spew out high levels of greenhouse gas.

Researchers at the University of Leeds have now found an energy-efficient way to make hydrogen out of used vegetable oils discarded by restaurants, takeaways and pubs. Not only does the process generate some of the energy needed to make the hydrogen gas itself, it is also essentially carbon-neutral.

“We are working towards a vision of the hydrogen economy,” said Dr Valerie Dupont, who is leading the Leeds-based project. “Hydrogen — based fuel could potentially be used to run our cars or even drive larger scale power plants, generating the electricity we need to light our buildings, run our kettles and fridges, and power our computers. But hydrogen does not occur naturally, it has to be made. With this process, we can do that in a sustainable way by recycling waste materials, such as used cooking oil.”

Hydrogen can already be made quite easily from simple fossil fuels, such as natural gas. The fuel is mixed with steam in the presence of a metal catalyst then heated to above 800 degrees centigrade to form hydrogen and carbon dioxide.

However when much more complex fuels are used, such as waste vegetable oil, it is difficult to make very much hydrogen using this method without raising the temperature even further. The reactions could be run at lower temperatures but the catalysts would quickly become poisoned by residues left over from the dirty oil. In short, the process is not only expensive but also environmentally unsound.

Dr Dupont and colleagues have perfected a two-stage process that is essentially self-heating. To begin, the nickel catalyst is blasted with air to form nickel oxide — an ‘exothermic’ process that can raise the starting temperature of 650 degrees by another 200 degrees. The fuel and steam mixture then reacts with the hot nickel oxide to make hydrogen and carbon dioxide.

The researchers also added a special ’sorbent’ material to trap all the carbon dioxide produced, leaving them with pure hydrogen gas. This trick eliminated the greenhouse gas emissions and also forced the reaction to keep running, increasing the amount of hydrogen made.

“The hydrogen starts to be made almost straight away, you don’t have to wait for all of the catalyst to be turned into pure nickel,” Dr Dupont said. “So as well as the generation of heat, this is another way that makes the process very efficient.”

The researchers have shown that the two-stage process works well in a small, test reactor. They now want to scale-up the trials and make larger volumes of hydrogen gas over longer periods of time.

Monday, February 8, 2010

Helium clue found in echo of the big bang - space

Helium clue found in echo of the big bang - - New Scientist

THE subtle signal of ancient helium has shown up for the first time in light left over from the big bang. The discovery will help astronomers work out how much of the stuff was made during the big bang and how much was made later by stars.

Helium is the second-most abundant element in the universe after hydrogen. The light emitted by old stars and clumps of hot pristine gas from the early universe suggest helium made up some 25 per cent of the ordinary matter created during the big bang.

The new data provides another measure. A trio of telescopes has found helium's signature in the cosmic microwave background (CMB, pictured), radiation emitted some 380,000 years after the big bang. The patterns in this radiation are an important indicator of the processes at work at that time. Helium affects the pattern because it is heavier than hydrogen and so alters the way pressure waves must have travelled through the young cosmos. But helium's effect on the CMB was on a scale too small to resolve until now.

Friday, December 18, 2009

Cosmic Treasure Trove of Heavy Metals Found

Cosmic Treasure Trove of Heavy Metals Found

An orbiting X-ray observatory has found the largest known reservoir of rare heavy metals in the universe.

The lightweights of the periodic table, hydrogen and helium, are the most abundant elements in the cosmos — they're the key fuels of stellar engines.

But more familiar to us Earthlings are the heavier elements that make up the rest of the table, though these heftier elements are rare in the universe at large.

Recently, astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known cache of rare metals in the universe to date.

Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster, which lies 225 million light-years from Earth. The metallic atoms are part of the hot gas, or intergalactic medium, that lies between 190 galaxies within the cluster.

"This is the first detection of chromium and manganese from a cluster," says Takayuki Tamura, an astrophysicist at the Japan Aerospace Exploration Agency who led the Perseus study. "Previously, these metals were detected only from stars in the Milky Way or from other galaxies. This is the first detection in intergalactic space."

Wednesday, November 18, 2009

Is Ammonia the smart new Hydrogen

The trouble with hydrogen as an energy source is that, as a gas, it’s not very energy-dense, it can explode, and it’s tough to transport.

So for the last 5 years the Iowa Energy Center at Iowa State University has been holding annual conferences on the use of ammonia as a fuel, and some of that dreaming is now coming out of the lab.

The chemical formula for ammonia is NH3. Combined with CO2 you know it as urea, the main component in urine. There are patents on producing anhydrous ammonia (the kind useful as fuel) from urea but currently the main feedstock for it is natural gas. Ammonia produced in this way is called “brown ammonia.”

The most recent Iowa State ammonia conference was held in Kansas City, and featured demonstrations of a car running on ammonia, and explanations of ammonia as a direct fuel (replacing hydrogen) for fuel cells, as well as many sessions on storing and transporting it.

Wizard Power in Australia has demonstrated a closed loop energy system. In this system solar energy converts hydrogen and nitrogen gas to ammonia, the ammonia is a feedstock for energy production, and nothing gets out.

A hydrogen energy cycle solves many of the problems we have with carbon energy, and with water as the “pollution” it can help solve the world’s water shortages. Ammonia has all these advantages, plus it can deal with agricultural pollution. And it’s more cost-efficient.

That’s why SunBorne Energy of India is funding research at the University of South Florida that hopes to use ammonia to cut the costs of solar energy by half, and produce energy at lower temperatures.

But note that connection with urea again. A coal-fired power plant in Wisconsin is testing the use of chilled ammonia to extract carbon directly, which could make clean coal a reality.

So hydrogen is smart energy. It bypasses the carbon cycle and gives us water as a by-product. But ammonia is smarter, because it is more energy dense, it is readily transported, and because it connects with carbon in the same way your own bladder does.