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Showing posts with label Orbits. Show all posts
Showing posts with label Orbits. Show all posts

Monday, May 27, 2013

3D Printing: Food in Space


3D Printing

NASA and a Texas company are exploring the possibility of using a "3D printer" on deep space missions in a way where the "D" would stand for dining.


NASA has awarded a Small Business Innovation Research (SBIR) Phase I contract to Systems and Materials Research Consultancy of Austin, Texas to study the feasibility of using additive manufacturing, better known as 3D printing, for making food in space. Systems and Materials Research Consultancy will conduct a study for the development of a 3D printed food system for long duration space missions. Phase I SBIR proposals are very early stage concepts that may or may not mature into actual systems. This food printing technology may result in a phase II study, which still will be several years from being tested on an actual space flight.

As NASA ventures farther into space, whether redirecting an asteroid or sending astronauts to Mars, the agency will need to make improvements in life support systems, including how to feed the crew during those long deep space missions. NASA's Advanced Food Technology program is interested in developing methods that will provide food to meet safety, acceptability, variety, and nutritional stability requirements for long exploration missions, while using the least amount of spacecraft resources and crew time. The current food system wouldn't meet the nutritional needs and five-year shelf life required for a mission to Mars or other long duration missions. Because refrigeration and freezing require significant spacecraft resources, current NASA provisions consist solely of individually prepackaged shelf stable foods, processed with technologies that degrade the micronutrients in the foods.

Additionally, the current space food is selected before astronauts ever leave the ground and crew members don't have the ability to personalize recipes or really prepare foods themselves. Over long duration missions, a variety of acceptable food is critical to ensure crew members continue to eat adequate amounts of food, and consequently, get the nutrients they need to maintain their health and performance. 

NASA is funding this phase I six-month $125,000 study on 3D printing of foods to determine the capability of this technology to enable nutrient stability and provide a variety of foods from shelf stable ingredients, while minimizing crew time and waste. NASA selected this proposal because the research team, subcontractors and consultants included premier food rheology and flavor expertise that would be required for a novel product development system. The work plan for this feasibility study also was well laid out and the technology offers the potential to meet some of the food requirements using basic food components for long duration missions. 

NASA recognizes in-space and additive manufacturing offers the potential for new mission opportunities, whether "printing" food, tools or entire spacecraft. Additive manufacturing offers opportunities to get the best fit, form and delivery systems of materials for deep space travel. This's why NASA is a leading partner in the president's National Network for Manufacturing Innovation and the Advanced Manufacturing Initiative. 

3D printing is just one of the many transformation technologies that NASA is investing in to create the new knowledge and capabilities needed to enable future space missions while benefiting life here on Earth. 

Source:
www.nasa.gov

Tuesday, April 16, 2013

First Shuttle Launch


A new era in space flight began on April 12, 1981, when Space Shuttle Columbia, or STS-1, soared into orbit from NASA's Kennedy Space Center in Florida.

Astronaut John Young, a veteran of four previous spaceflights including a walk on the moon in 1972, commanded the mission. Navy test pilot Bob Crippen piloted the mission and would go on to command three future shuttle missions. The shuttle was humankind's first re-usable spacecraft. The orbiter would launch like a rocket and land like a plane. The two solid rocket boosters that helped push them into space would also be re-used, after being recovered in the ocean. Only the massive external fuel tank would burn up as it fell back to Earth. It was all known as the Space Transportation System.

Twenty years prior to the historic launch, on April 12, 1961, the era of human spaceflight began when Russian Cosmonaut Yuri Gagarin became the first human to orbit the Earth in his Vostock I spacecraft. The flight lasted 108 minutes.

Pictured here: a timed exposure of STS-1, at Launch Pad A, Complex 39, turns the space vehicle and support facilities into a night- time fantasy of light. Structures to the left of the shuttle are the fixed and the rotating service structure.

Image Credit: NASA

Sunday, December 23, 2012

Apollo 8: Christmas at the Moon

Apollo 8, the first manned mission to the moon, entered lunar orbit on Christmas Eve, Dec. 24, 1968. That evening, the astronauts held a live broadcast from lunar orbit, during which they showed pictures of the Earth and moon as seen from their spacecraft.

Christmas Eve, 1968. As one of the most turbulent, tragic years in American history drew to a close, millions around the world were watching and listening as the Apollo 8 astronauts -- Frank Borman, Jim Lovell and Bill Anders -- became the first humans to orbit another world.

As their command module floated above the lunar surface, the astronauts beamed back images of the moon and Earth and took turns reading from the book of Genesis, closing with a wish for everyone "on the good Earth."

"We were told that on Christmas Eve we would have the largest audience that had ever listened to a human voice," recalled Borman during 40th anniversary celebrations in 2008. "And the only instructions that we got from NASA was to do something appropriate."

"The first ten verses of Genesis is the foundation of many of the world's religions, not just the Christian religion," added Lovell. "There are more people in other religions than the Christian religion around the world, and so this would be appropriate to that and so that's how it came to pass."

The mission was also famous for the iconic "Earthrise" image, snapped by Anders, which would give humankind a new perspective on their home planet. Anders has said that despite all the training and preparation for an exploration of the moon, the astronauts ended up discovering Earth. 

The Apollo 8 astronauts got where they were that Christmas Eve because of a bold, improvisational call by NASA. With the clock ticking on President Kennedy's challenge to land on the moon by decade's end, delays with the lunar module were threatening to slow the Apollo program. So NASA decided to change mission plans and send the Apollo 8 crew all the way to the moon without a lunar module on the first manned flight of the massive Saturn V rocket.

The crew rocketed into orbit on December 21, and after circling the moon 10 times on Christmas Eve, it was time to come home. On Christmas morning, mission control waited anxiously for word that Apollo 8's engine burn to leave lunar orbit had worked. They soon got confirmation when Lovell radioed, "Roger, please be informed there is a Santa Claus."

The crew splashed down in the Pacific on December 27. A lunar landing was still months away, but for the first time ever, men from Earth had visited the moon and returned home safely.

Monday, December 19, 2011

Comet Lovejoy Plunges into the Sun and Survives

COMET LOVEJOY
This morning, an armada of spacecraft witnessed something that many experts thought impossible. Comet Lovejoy flew through the hot atmosphere of the sun and emerged intact.

"It's absolutely astounding," says Karl Battams of the Naval Research Lab in Washington DC. "I did not think the comet's icy core was big enough to survive plunging through the several million degree solar corona for close to an hour, but Comet Lovejoy is still with us."

The comet's close encounter was recorded by at least five spacecraft: NASA's Solar Dynamics Observatory and twin STEREO probes, Europe's Proba2 microsatellite, and the ESA/NASA Solar and Heliospheric Observatory. The most dramatic footage so far comes from SDO, which saw the comet go in (below) and then come back out again (above).
In the SDO movies, the comet's tail wriggles wildly as the comet plunges through the sun's hot atmosphere only 120,000 km above the stellar surface. This could be a sign that the comet was buffeted by plasma waves coursing through the corona. Or perhaps the tail was bouncing back and forth off great magnetic loops known to permeate the sun's atmosphere. No one knows.

"This is all new," says Battams. "SDO is giving us our first look at comets traveling through the sun's atmosphere. How the two interact is cutting-edge research."

"The motions of the comet material in the sun's magnetic field are just fascinating," adds SDO project scientist Dean Pesnell of the Goddard Space Flight Center. "The abrupt changes in direction reminded me of how the solar wind affected the tail of Comet Encke in 2007 (view movie)."

Comet Lovejoy was discovered on Dec. 2, 2011, by amateur astronomer Terry Lovejoy of Australia. Researchers quickly realized that the new find was a member of the Kreutz family of sungrazing comets. Named after the German astronomer Heinrich Kreutz, who first studied them, Kreutz sungrazers are fragments of a single giant comet that broke apart back in the 12th century (probably the Great Comet of 1106). Kreutz sungrazers are typically small (~10 meters wide) and numerous. The Solar and Heliospheric Observatory sees one falling into the sun every few days.

At the time of discovery, Comet Lovejoy appeared to be at least ten times larger than the usual Kreutz sungrazer, somewhere in the in the 100 to 200 meter range. In light of today's events, researchers are re-thinking those numbers.

"I'd guess the comet's core must have been at least 500 meters in diameter; otherwise it couldn't have survived so much solar heating," says Matthew Knight. "A significant fraction of that mass would have been lost during the encounter. The remains are probably much smaller."

SOHO and NASA's twin STEREO probes are monitoring the comet as it recedes from the sun. It is still very bright and should remain in range of the spacecrafts' cameras for several days to come.

What happens next is anyone's guess.

"There is still a possibility that Comet Lovejoy will start to fragment," continues Battams. "It' been through a tremendously traumatic event; structurally, it could be extremely weak. On the other hand, it could hold itself together and disappear back into the recesses of the solar system."

"It's hard to say," agrees Knight. "There has been so little work on what happens to sungrazing comets after perihelion (closest approach). This continues to be fascinating."

Thursday, December 15, 2011

NASA's Fermi Shows That Tycho's Star Shines in Gamma Rays

Gamma Ray
In early November 1572, observers on Earth witnessed the appearance of a "new star" in the constellation Cassiopeia, an event now recognized as the brightest naked-eye supernova in more than 400 years. It's often called "Tycho's supernova" after the great Danish astronomer Tycho Brahe, who gained renown for his extensive study of the object. Now, years of data collected by NASA's Fermi Gamma-Ray Space Telescope reveal that the shattered star's remains shine in high-energy gamma rays.

The detection gives astronomers another clue in understanding the origin of cosmic rays, subatomic particles -- mainly protons -- that move through space at nearly the speed of light. Exactly where and how these particles attain such incredible energies has been a long-standing mystery because charged particles speeding through the galaxy are easily deflected by interstellar magnetic fields. This makes it impossible to track cosmic rays back to their sources.

"Fortunately, high-energy gamma rays are produced when cosmic rays strike interstellar gas and starlight. These gamma rays come to Fermi straight from their sources," said Francesco Giordano at the University of Bari and the National Institute of Nuclear Physics in Italy. He is the lead author of a paper describing the findings in the Dec. 7 edition of The Astrophysical Journal Letters.

Better understanding the origins of cosmic rays is one of Fermi's key goals. Its Large Area Telescope (LAT) scans the entire sky every three hours, gradually building up an ever-deeper view of the gamma-ray sky. Because gamma rays are the most energetic and penetrating form of light, they serve as signposts for the particle acceleration that gives rise to cosmic rays.

"This detection gives us another piece of evidence supporting the notion that supernova remnants can accelerate cosmic rays," said co-author Stefan Funk, an astrophysicist at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), jointly located at SLAC National Accelerator Laboratory and Stanford University, Calif.

In 1949, physicist Enrico Fermi -- the satellite's namesake -- suggested that the highest-energy cosmic rays were accelerated in the magnetic fields of interstellar gas clouds. In the decades that followed, astronomers showed that supernova remnants may be the galaxy's best candidate sites for this process.

When a star explodes, it is transformed into a supernova remnant, a rapidly expanding shell of hot gas bounded by the blast's shockwave. Scientists expect that magnetic fields on either side of the shock front can trap particles between them in what amounts to a subatomic pingpong game.

"A supernova remnant's magnetic fields are very weak relative to Earth's, but they extend across a vast region, ultimately spanning thousands of light-years. They have a major influence on the course of charged particles," said co-author Melitta Naumann-Godo at Paris Diderot University and the Atomic Energy Commission in Saclay, France, who led the study with Giordano.

As they shuttle back and forth across the supernova shock, the charged particles gain energy with each traverse. Eventually they break out of their magnetic confinement, escaping the supernova remnant and freely roaming the galaxy.

The LAT's ongoing sky survey provides additional evidence favoring this scenario. Many younger remnants, like Tycho's, tend to produce more high-energy gamma rays than older remnants. "The gamma-ray energies reflect the energies of the accelerated particles that produce them, and we expect more cosmic rays to be accelerated to higher energies in younger objects because the shockwaves and their tangled magnetic fields are stronger," Funk added. By contrast, older remnants with weaker shockwaves cannot retain the highest-energy particles, and the LAT does not detect gamma rays with corresponding energies.


The supernova of 1572 was one of the great watersheds in the history of astronomy. The star blazed forth at a time when the starry sky was regarded as a fixed and unchanging part of the universe. Tycho's candid account of his own discovery of the strange star gives a sense of how radical an event it was.

The supernova first appeared around Nov. 6, but poor weather kept it from Tycho until Nov. 11, when he noticed it during a walk before dinner. "When I had satisfied myself that no star of that kind had ever shone forth before, I was led into such perplexity by the unbelievability of the thing that I began to doubt the faith of my own eyes, and so, turning to the servants who were accompanying me, I asked them whether they too could see a certain extremely bright star…. They immediately replied with one voice that they saw it completely and that it was extremely bright," he recalled.

The supernova remained visible for 15 months and exhibited no movement in the heavens, indicating that it was located far beyond the sun, moon and planets. Modern astronomers estimate that the remnant lies between 9,000 and 11,000 light-years away.

After more than two and a half years of scanning the sky, LAT data clearly show that an unresolved region of GeV (billion electron volt) gamma-ray emission is associated with the remnant of Tycho's supernova. (For comparison, the energy of visible light is between about 2 and 3 electron volts.)

Keith Bechtol, a KIPAC graduate student who is also based at SLAC, was one of the first researchers to notice the potential link. "We knew that Tycho's supernova remnant could be an important find for Fermi because this object has been so extensively studied in other parts of the electromagnetic spectrum. We thought it might be one of our best opportunities to identify a spectral signature indicating the presence of cosmic-ray protons," he said.

The science team's model of the emission is based on LAT observations, along with higher-energy TeV (trillion electron volt) gamma rays mapped by ground-based facilities and radio and X-ray data. The researchers conclude that a process called pion production best explains the emission. First, a proton traveling close to the speed of light strikes a slower-moving proton. This interaction creates an unstable particle -- a pion -- with only 14 percent of the proton's mass. In just 10 millionths of a billionth of a second, the pion decays into a pair of gamma rays.

If this interpretation is correct, then somewhere within the remnant, protons are being accelerated to near the speed of light, and then interacting with slower particles to produce gamma rays, the most extreme form of light. With such unbelievable goings-on in what's left of his "unbelievable" star, it's easy to imagine that Tycho Brahe himself might be pleased.

Sunday, December 11, 2011

Cassini to Make a Double Play

A quartet of Saturn's moons, from tiny to huge, surround and are embedded within the planet's rings in this Cassini composition.
In an action-packed day and a half, NASA's Cassini spacecraft will be making its closest swoop over the surface of Saturn's moon Dione and scrutinizing the atmosphere of Titan, Saturn's largest moon.
The closest approach to Dione, about 61 miles (99 kilometers) above the surface, will take place at about 1:39 a.m. PST (4:39 a.m. EST) on Dec. 12. One of the questions Cassini scientists will be asking during this flyby is whether Dione's surface shows any signs of activity. Understanding Dione's internal structure will help address that question, so Cassini's radio science instrument will learn how highly structured the moon's interior is by measuring variations in the moon's gravitational tug on the spacecraft. The composite infrared spectrometer instrument will also look for heat emissions along fractures on the moon's surface.
Cassini will also be probing whether Dione, like another Saturnian moon, Rhea, has a tenuous atmosphere. Scientists expect a Dionean atmosphere – if there is one – to be much more ethereal than even Rhea's. Research published in journal Geophysical Research Letters and led by Sven Simon, a Cassini magnetometer team member at the University of Cologne, Germany, found magnetic field disturbances around Dione, hinting at a tenuous atmosphere. But scientists hope to get stronger confirmation by "tasting" the space around the moon with Cassini's ion and neutral mass spectrometer.
On Cassini's journey out from Dione toward Titan, the imaging science subsystem will turn back to look at Dione's distinctive, wispy fractures and a ridge called Janiculum Dorsa.
Cassini will approach within about 2,200 milles (3,600 kilometers) of the Titan surface, at about 12:11 p.m. PST (3:11 PM EST) on Dec. 13. At Titan, the composite infrared spectrometer will be making measurements to understand how the seasonal transition from spring to summer affects wind patterns in the atmosphere near Titan's north pole. It will also search for mist.
The visual and infrared mapping spectrometer and imaging science subsystem will be observing the same equatorial deserts where the imaging science subsystem saw sudden and dramatic surface changes last year, when Titan was experiencing early northern spring. One possibly theory is that rainstorms caused these changes. As Cassini recedes from Titan, the imaging cameras will also continue to observe the moon for another day to monitor any new weather systems. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.


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