1st African American Man Dates Back 338,000 Years.

A miniscule bit of DNA from an African American man now living in South Carolina has been traced back 338,000 years, according to a new study.

The man’s Y chromosome — a hereditary factor determining male sex — has a history that’s so old, it even predates the age of the oldest known Homo sapiens fossils, according to the report, published in the American Journal of Human Genetics.

The fellow’s chromosome turned out to carry a rare mutation, which researchers matched to a similar chromosome in the Mbo, a population living in a tiny area of western Cameroon in sub-Saharan Africa.

“Our analysis indicates this lineage diverged from previously known Y chromosomes about 338,000 ago, a time when anatomically modern humans had not yet evolved,” Michael Hammer, who worked on the study, said in a press release.

“This pushes back the time the last common Y chromosome ancestor lived by almost 70 percent.”

Hammer is an associate professor in the University of Arizona’s department of ecology and evolutionary biology and a research scientist at the UA’s Arizona Research Labs.

The DNA detective work began after the South Carolinian submitted a small tissue sample to theNational Geographic Genographic Project. The researchers were shocked after they noticed none of the genetic markers used to assign lineages to known Y chromosome groupings were found.

They sent the man’s DNA sample to Family Tree DNA for sequencing. Fernando Mendez, a postdoctoral researcher in Hammer’s lab, led the effort to analyze the DNA sequence. It included more than 240,000 base pairs of the Y chromosome.

Searches through a huge database led to the Mbo connection.

The scientists could then estimate the emergence of the chromosome mutation based on rates of change, creating a sort of “family tree” for the chromosome.

The discovery doesn’t necessarily mean that we all descended from an ancestor living in western Cameroon.

“It is a misconception that the genealogy of a single genetic region reflects population divergence,” Hammer explained. “Instead, our results suggest that there are pockets of genetically isolated communities that together preserve a great deal of human diversity.”

Still, Hammer said, “It is likely that other divergent lineages will be found, whether in Africa or among African-Americans in the U.S. and that some of these may further increase the age of the Y chromosome tree. There has been a lot of hype with people trying to trace their Y chromosome to different tribes, but this individual from South Carolina can say he did it.”

The study has even further implications. It strengthens the belief that there is no “mitochondrial Eve” or “Y chromosome Adam.”

All of humankind, as a result, did not descend from exactly one pair of humans that lived at a certain point in human evolution.

Plug-In Hybrid Vehicle Has Wings.(Flying Car Gets FAA Approval).

Just getting on a commercial airplane is tough enough these days, so it’s no surprise that Terrafugia has taken so long to navigate regulatory hurdles. Earlier this year, it cleared a major one when the FAA classified the Transition as a Light-Sport Aircraft, which means drivers don’t need a pilot’s license, just FAA certification in this category. While the company has been working on getting the Transition in the air, Terrafugia hasn’t stopped designing.

That’s where the TF-X plan comes in. Unlike the two-seater Transition, this new street-legal aircraft will seat four and run on electricity. That means the engine will recharge the batteries in the air or it could be plugged into a charging station on the ground. According to Terrafugia, the vehicle will also have electric ground drive and electric power assist for takeoff and landing.

Other cool features include retractable wings and the propellers that open from two motor pods. Initially the propellers point up for takeoff, then the motor pods tilt forward until the vehicle cruises and after that the propellers can fold in. The TF-X will have a non-stop flight range of at least 500 miles, and is expected to be able to automatically avoid other air traffic, bad weather, and restricted and tower-controlled airspace, according to the website, as well as implement an emergency auto-land at the nearest airport, if the operator became unresponsive. See more details in the Youtube video.

The vehicle will also have extensive safety features such as a parachute system to prevent it from crashing horribly should something go seriously wrong. Terrafugia indicated that learning how to safely operate the TF-X will take the average person five hours; a light-sport aircraft certification takes an additional 20 hours.

Dutch ‘Flying Car’ Takes to the Skies

Before you get your hopes up, the TF-X will likely be in development for eight to 12 years and cost way, way more than a new car. According to the company, Transition owners will have the first shot at purchasing these vehicles when they do get produced. Nevertheless, I look forward to the day when we hear drivers turn to their passengers and say, “Roads? Where we’re going, we don’t need roads.”

10,000 to 15,000 years ago woolly female mammoth found in Arctic Ocean with flowing blood and well preserved muscle tissue.

A researcher in Yakutsk on May 13 next to a carcass of a female mammoth found on an island in the Arctic Ocean. Russian scientists claimed Wednesday they have discovered blood in the carcass of a woolly mammoth, adding that the rare find could boost their chances of cloning the prehistoric animal.

An expedition led by Russian scientists earlier this month uncovered the well-preserved carcass of a female mammoth on a remote island in the Arctic Ocean.

Semyon Grigoryev, the head of the expedition, said the animal died at the age of around 60 some 10,000 to 15,000 years ago, and that it was the first time that an old female had been found.

But what was more surprising was that the carcass was so well preserved that it still had blood and muscle tissue.

"When we broke the ice beneath her stomach, the blood flowed out from there, it was very dark," Grigoryev, who is a scientist at the Yakutsk-based Northeastern Federal University, told AFP.

"This is the most astonishing case in my entire life. How was it possible for it to remain in liquid form? And the muscle tissue is also red, the colour of fresh meat," he added.

Grigoryev said that the lower part of the carcass was very well preserved as it ended up in a pool of water that later froze over. The upper part of the body including the back and the head are believed to have been eaten by predators, he added.

"The forelegs and the stomach are well preserved, while the hind part has become a skeleton."

The discovery, Grigoryev said, gives new hope to researchers in their quest to bring the woolly mammoth back to life.

"This find gives us a really good chance of finding live cells which can help us implement this project to clone a mammoth," he said.

"Previous mammoths have not had such well-preserved tissue."

Last year, Grigoryev's Northeastern Federal University signed a deal with cloning pioneer Hwang Woo-Suk of South Korea's Sooam Biotech Research Foundation, who in 2005 created the world's first cloned dog.

                                   

In the coming months, mammoth specialists from South Korea,Russia and the United States are expected to study the remains which the Russian scientists are now keeping at an undisclosed northern location.

"I won't say where it is being kept or it may get stolen," he said.

Last year, a teenager from a nomadic family in Russia's north stumbled upon a massive well-preserved woolly mammoth, in what scientists described as the best such discovery since 1901.

The young male mammoth was dubbed Zhenya after the nickname of the boy who discovered it.

Global warming has thawed ground in northern Russia that is usually almost permanently frozen, leading to the discoveries of a number of mammoth remains.

Printing solar cells(10–50 watts of power per square meter).

Scientists have produced the largest flexible, plastic solar cells in Australia – 10 times the size of what they were previously able to – thanks to a new solar cell printer that has been installed at CSIRO.
The printer has allowed researchers from the Victorian Organic Solar Cell Consortium (VICOSC) – a collaboration between CSIRO, The University of Melbourne, Monash University and industry partners – to print organic photovoltaic cells the size of an A3 sheet of paper.

According to CSIRO materials scientist Dr Scott Watkins, printing cells on such a large scale opens up a huge range of possibilities for pilot applications.
"There are so many things we can do with cells this size," he says. "We can set them into advertising signage, powering lights and other interactive elements. We can even embed them into laptop cases to provide backup power for the machine inside."
The new printer, worth $200,000 Australian dollars, is a big step up for the VICOSC team. In just three years they have gone from making cells the size of a fingernail to cells 10 cm square. Now with the new printer they have jumped to cells that are 30 cm wide.
"Eventually we see these being laminated to windows that line skyscrapers. By printing directly to materials like steel, we'll also be able to embed cells onto roofing materials."
VICOSC project coordinator and University of Melbourne researcher Dr David Jones says that one of the great advantages of the group's approach is that they're using existing printing techniques, making it a very accessible technology.
"We're using the same techniques that you would use if you were screen printing an image on to a T-Shirt," he says.
Using semiconducting inks, the researchers print the cells straight onto paper-thin flexible plastic or steel. With the ability to print at speeds of up to ten metres per minute, this means they can produce one cell every two seconds.
As the researchers continue to scale up their equipment, the possibilities will become even greater.
"Eventually we see these being laminated to windows that line skyscrapers," Dr Jones says. "By printing directly to materials like steel, we'll also be able to embed cells onto roofing materials."
The organic photovoltaic cells, which produce 10–50 watts of power per square metre, could even be used to improve the efficiency of more traditional silicon solar panels.
"The different types of cells capture light from different parts of the solar spectrum. So rather than being competing technologies, they are actually very complementary," Dr Watkins says.
The scientists predict that the future energy mix for the world, including Australia, will rely on many non-traditional energy sources. "We need to be at the forefront of developing new technologies that match our solar endowment, stimulate our science and support local, high-tech manufacturing.
"While the consortium is focused on developing applications with current industrial partners there are opportunities to work with other companies through training programs or pilot-scale production trials," he says.
As part of the consortium, a complementary screen printing line is also being installed at nearby Monash University. Combined, they will make the Clayton Manufacturing and Materials Precinct one of the largest organic solar cell printing facilities in the world.
The Victorian Organic Solar Cell Consortium is a research collaboration between CSIRO, The University of Melbourne, Monash University, BlueScope Steel, Robert Bosch SEA, Innovia Films and Innovia Security. It is supported by the Victorian State Government and the Australian Government through the Australian Renewable Energy Agency.

AIR BUBBLES IN WATER GLOWS WHEN COLLAPSED.

It's called sonoluminescence. No one knows exactly why this occurs, but there are a lot of different hypotheses. One of the most common explanations is that when the bubble collapses, the air inside gets pressurized. Increasing the pressure on a gas increases the temperature of the gas. During sonoluminescence, the temperature inside the tiny bubbles becomes so great that the gas begins to glow.

Another hypothesis is that the collapsing bubble lends energy to prolong the life of the otherwise quickly annihilating photons that are spontaneously generated in a vacuum. Sonoluminescence could also be the product of the way photons can pop into and out of existence; the sudden collapse of the bubble making the photons noticeable to those in the macro world.

THE NEXT SMART COMPUTER WORLD -- Google Glass – Augmented reality

With speculation of Apple’s growing interest in wearable computing and a smart watch-like gadget the company’s reportedly working on, it’s worth remembering Google entered the space in a big way with last year’s astonishing on-stage demonstration of its Android-driven augmented-reality eye-wear, Google Glass.

Project Glass products display information in a smartphone-like format hands-free, and can interact with the Internet via natural language voice commands. The eye wear’s functionality and minimalist appearance (aluminum strip with 2 nose pads) has been compared to Steve Mann’s Eye Tap  and uses Google’s Android operating system.

Essentially, Glass’ main priority is to move the interactions we’ve grown accustom to with our smartphones and tablets to the hands-free convenience of a pair of glasses. An Android-powered head-mounted display resides just above the right eye, producing a small heads-up display image with information like travel directions and video messaging, all accessible by Siri-like voice commands. A 720p camera is embedded in the front of the device, allowing the wearer to take pictures or perhaps even stream live video.
Project Glass is being developed by Google X Lab which has worked on other futuristic technologies such as driverless cars. The project was announced on Google+ by Babak Parviz, an electrical engineer who has also worked on putting displays into contact lenses; Steve Lee, a project manager and “geolocation specialist”; and Sebastian Thrun, who developed Udacity  as well as worked on the self-driving car project. Google has patented the design of Project Glass.Thad Starner is a Technical/Lead Manager on the project.



Google co-founder Sergey Brin took the stage at TED Wednesday morning for an unscheduled, low-key talk on Google Glass. His aim: to reveal a little bit of the thinking behind the two-year-old project and why he thinks the eyeglass-based always-connected screen is less intrusive than constantly checking your smartphone.Brin admitted he was as guilty as anyone else of repeatedly checking email and social media on his phone “as if it was something really important.” It was comparable to a smoking habit, he said. “I had a nervous tic. But with Google Glass, I’ve really enjoyed exploring the world more.”Finally, he cautioned that the device had a long way to go still — and that the success of Google Glass was far from assured, despite tremendous interest in the tech world.

Prototypes
Though head-worn displays for augmented reality are not a new idea, the project has drawn media attention primarily due to its backing by Google, as well as the prototype design, which is smaller and slimmer than previous designs for head-mounted displays The first Project Glass demo resembles a pair of normal eyeglasses where the lens is replaced by a head-up display.  In the future, new designs may allow integration of the display into people’s normal eye wear.

 The New York Times originally reported that Google Glass would be available to the public for “around the cost of current smartphones” by the end of 2012, but other reports have stated that the glasses are not expected to be available for purchase soon. The product (Google Glass Explorer Edition) will be available to United States Google I/O developers for $1,500, to be delivered in early 2013,while a consumer version is stated to be ready within a year of that.

Google originally targeted 2014 for a consumer release when it revealed Project Glass last year, but the time frame has seemingly sped up in recent months, what with developer hackathons in San Francisco and New York and this week’s announcement that people looking to put Glass to creative use could go through an application process to preorder the augmented reality specs for $1,500.

The plastic components of Google Glass will debut in five colors: gray, orange, black, white, and light blue.
An “Explorer” edition of Glass will snap on to a pair of sunglasses, and there is talk of deals with prescription spectacle sellers Warby Parker to produce a Glass model for those of us withweaker vision. The device links up with built-in Wi-Fi, and can tether via Android or iPhone.

Need of Google Glass
Like any piece of new tech, the usefulness of Glass will probably vary from person to person. Primarily, Glass is a way to communicate hands-free, to keep in touch with our loved-ones and friends without the need to hold onto a smartphone. But the device is also a way to share experiences. A recent demo video from Google attempts to show “how it feels” to use Glass, and the implications of streaming a truly first-person perspective video out into the world are massive.
Cool things you can do by Google glass:
1. Menu
Glass shows off what options users have available, ranging from taking pictures, engaging in a Google Hangout, recording a video, or sharing with others.

2. Reminders
Glass can pop up a reminder on your screen to, well, remind you of an upcoming appointment or other meeting that you have planned.

3. Weather
Like one of the cards that pops up in Android, Google Glass hopes to be able to deliver to you the current weather.

4. Dictate Texts
There’s no reason why Glass can’t be used to dictate texts or short messages to others, using the built-in microphone, Google’s cloud-based speech recognition, and a wireless connection.

5. Travel Alerts
I’ve never seen an alert when a public transportation link has been severed or is inoperable, but I assume Google has the capability to do so. This would be a handy feature.

6. Maps
I’m not sure a “full-screen” overlay would be the most ideal rendering of map data, but this would certainly be a handy feature to have in most cases.

7. Photos
Naturally, Google Glass users can take photos. This is in Glass today, although the photos (unsurprisingly) seem to have rather poor quality compared to even a mobile phone camera.8. Hangout(With screen sharing)
A nice touch. With Glass, there’s every reason to believe that not only could you join a Google Hangout, you could share what you’re seeing. In fact, with no self-facing camera, that might be the only way to communicate.

And a lot of other things like sharing locations, viewing interior maps, turn by turn directions and many more.
Glass will mean the next step towards a future where wearable computing is the norm. Or maybe, it will take years before such devices grow into common usage. Regardless, Glass has the potential to completely alter the computing and mobile industries.
Google glass will change the future!!!

Rewriting memories with red herrings.

Certain types of long term memories can be “rewritten” without drugs or surgery, according to a new study that experts say offers hope for sufferers of post traumatic stress disorder.

The study, conducted by Jason C. K. Chan and Jessica A. LaPaglia from Iowa State University, showed that declarative memories — memories of events, facts or details that can be consciously recalled — are open to change and can be disrupted through exposure to false details or alternative narratives.

The researchers designed an experiment in which participants were asked to watch an episode of the TV show 24 about a fictional terrorist attack.

Soon after the video ended, the participants were asked to recount the plot details. They were then asked to listen to an audio recording of a person explaining the video storyline, but with elements of misinformation woven throughout — for example, the suggestion that the villain used a stun gun on an airline attendant, when in the video it had been a hypodermic needle.

After being exposed to misinformation about plot details, the study subjects fared much worse at remembering the real details but only if the ’re-learning' occurred quite soon after the memory was first recalled.

“Here we show that existing declarative memories can be selectively impaired by using a noninvasive retrieval–relearning technique,” the authors said in their paper, which was published in the journal PNAS.

“These results demonstrate that human declarative memory can be selectively rewritten during reconsolidation.”

Post Traumatic Stress Disorder

Kristyn Bates, Research Assistant Professor of Experimental and Regenerative Neuroscience at the University of Western Australia said the new study was very interesting.

“The first thing that came to mind was that the data presented in this study could really help inform as to the best treatments for people who have conditions such as post-traumatic stress disorder, where unwanted memories can have such a devastating impact on a person’s life, through to better learning techniques for students studying for exams,” said Dr Bates, who was not involved in the study.

“Because declarative memory involves diffuse neuronal networks, it has been difficult to study in humans, unlike motor and fear-based memories which have localised, distinct neurological substrates. The authors have conducted a very well designed study where they have attempted to uncover whether declarative or long-term memories can be manipulated in humans without the use of drugs, which may have adverse side effects on other aspects of cognitive function.”

The authors of the study demonstrated that the incorrect details had to be specific, rather than vague, in order to be consolidated into the original memory, she said.

“This may explain why the numerous distractions and stimuli we encounter each day don’t destabilise our declarative memories. The memory-disruption effect was even present for items that participants had previously correctly recalled.”

Dr Bates said that further research was needed but the new findings may help to explain why certain forms of therapy are more effective for post traumatic stress disorder sufferers than others and may have important implications for crime investigation and interviewing of eye-witnesses.

“It is well known that eye-witness accounts can be manipulated. This study implies that the methods of questioning may be important for gathering reliable evidence. Importantly, this is a non-pharmacological, non-invasive technique, thus reducing the possibility of unwanted side effects on other memories and other aspects of cognition.”

Jee Hyun Kim, DECRA Fellow in Behavioural Neuroscience at The Florey Institute of Neuroscience and Mental Health, also welcomed the new findings.

“This study provides evidence how a stable ‘consolidated’ memory can be altered by what the person experiences following its recall,” said Dr Kim, who was not involved in the study.

“We already know that, especially in forensic context, existing memories can be manipulated and/or falsely remembered. This study explains how confabulation can be spontaneous as well as provoked. Confabulation is believed to depend on both subconscious and conscious processes. So far, reconsolidation studies provided subconscious ways in how a memory can be changed. The new study shows the conscious way.”

Dr Kim said that if brain imaging studies could be done while subjects recalled misinformed memories and original memories, “perhaps we can decode what confabulated memory looks like in the brain.”

“This could be used to differentiate true versus confabulated testimonies from eye witnesses in the court, or in diseases where confabulation is rampant such as Alzheimer’s, or alcoholism.”

“Messing With” the Blood-Brain Barrier May Be Key to Treating a Host of Diseases.

A new understanding of the blood-brain barrier as a living, mutable organ may revolutionize the treatment of diseases such as cancer and Alzheimer's

During one of his famous staining experiments of the late 1800s—the kind that would eventually lead to a cure for syphilis and a Nobel Prize for Medicine—Paul Ehrlich stumbled on a conundrum that would haunt medicine down to the present day. When he injected dye into the bloodstream of mice, it penetrated every organ except the brain. Kidneys, livers and hearts turned a dark purplish-blue, clear and stark under his microscope, but the brain remained a pale whitish-yellow. When a student of his injected that same dye directly into the brain, the opposite happened: the brain itself turned blue, whereas the other organs did not. Clearly, the student thought, a barrier—in German, Blut-Hirn-Schranke—must exist between brain and blood.

It would take half a century and a microscope roughly 5,000 times more powerful than Ehrlich's for anyone to actually locate this barrier, hidden as it was inside the brain's blood vessels. The average human brain houses roughly 400 miles of such vessels. They bend and twist in an endless array of tangled loops, ultimately ensnaring every single one of the human brain's 100 billion or so neurons. The walls of all these vessels are lined with endothelial cells. To be sure, endothelial cells line the interior of all of the body's vasculature, but they are much more tightly packed in the brain's vessels than they are anywhere else in the body, which explains why neither Ehrlich's dyes nor most of the medications in existence could cross from the bloodstream into the brain.

In Brief

• For more than a century, scientists believed that the blood-brain barrier was a sacred, impermeable wall. In fact, it is made up of ordinary blood vessels with one extraordinary property: the cells that make up their lining are packed together so tightly that they allow very few substances to cross into brain tissue.
• The barrier is a vital organ in its own right, thrumming with activity as cells communicate with one another to decide which molecules to block and which ones to let through. Many more cells pass through the barrier than scientists previously realized.
• To reflect this new understanding, scientists now call the blood-brain barrier the neurovascular unit.
• Many believe that learning how to open and close it may be the key to curing a host of diseases.

Cracks in the Periodic Table.

The discovery of element 117 filled the last remaining gap in the periodic table as we know it. But even as it is being completed, the table may be losing its power.

In 2010 researchers in Russia announced they had synthesized the first few nuclei of element 117. This new type of atom does not yet have a name, because the science community traditionally waits for independent confirmation before it christens a new element. But barring any surprises, 117 has now taken its permanent place in the periodic table of elements.

All elements up to 116, plus element 118, had been found previously, and 117 filled the last remaining gap in the bottom row. This achievement marks a unique moment in history. When Dmitri Mendeleev—also Russian—and others created the periodic table in the 1860s, it was the first grand scheme to organize all the elements known to science at the time. Mendeleev left several spaces blank in his table, and he made the bold guess that someday new elements would be discovered that would fill those blanks. Countless revisions of the table followed, but all of them had gaps—until now. With element 117, the periodic table is complete for the first time.

In Brief

• The discovery of element 117 in 2010 completed for the first time the periodic table as we know it—at least until new discoveries will force chemists to extend it by adding a new row.
• Some recent additions, however, may differ in their chemistry from the elements in the same column, breaking the periodic rule that had defined the table for a century and a half.
• The surprising behavior may result from effects described by the special theory of relativity, which make some electron orbits tighter, among other effects.
• Nuclear physicists continue in their quest to synthesize new elements, which will have new types of electron orbitals—and to understand their chemistry from studying a handful of short-lived atoms.

A RoboBee Takes Off

RoboBee flight tests show how even tiny flapping-wing robots can be controlled

The RoboBee project at Harvard University is attempting to create a hive of small flying robots. the project’s creators detail the challenges of building and controlling such tiny robots. The first video depicts some early flight tests of RoboBee prototypes. The slow-motion shots show the RoboBee turning in four different directions after takeoff. You’ll also notice a small wire hanging from the bee’s underside—that’s to supply power. Any battery (or other known energy-storage system) strong enough to power the RoboBee would be too heavy to allow the robot to take flight.

In Brief

• RoboBees are flying robots the size of bees. Their size presents a huge assortment of physical and computational challenges. At such small dimensions, off-the-shelf parts such as motors and bearings will prove too inefficient, so the bees must employ specially designed artificial muscles to power and control flight.
• In addition, the tiny bees must think on their own, using miniature sensors to process environmental cues and processors to make decisions on what to do next.
• Like real bees, RoboBees will work best when employed as swarms of thousands of individuals, coordinating their actions without relying on a single leader. The hive must be resilient enough so that the group can complete its objectives even if many bees fail.

Space Suit Stuffing.

 Superinsulating aerogels are more than 85 percent air by volume, earning them the nickname “solid smoke.” Yet existing silica aerogels are brittle, like cheap Styrofoam. A much tougher alternative comes from the NASA Glenn Research Center and the Ohio Aerospace Institute, both in Cleveland, where scientists have invented new polymer-based versions some 500 times stronger. These aerogels, composed of heat-resistant polyimide plastics, are flexible enough to be folded in half. NASA engineers hope to use them as space suit insulation or as part of parachutelike decelerators to help safely deliver large payloads to the surface ofMars.

NASA Plans for 3-D Printing Rocket Engine Parts Could Boost Larger Manufacturing Trend.

The space agency is testing alternative manufacturing processes for faster, cheaper ways to make parts for its new Space Launch System

There is a lot riding on NASA's Space Launch System (SLS). Not only does the agency's first new heavy-lift booster since the Saturn 5 that took U.S. astronauts to the moon play a central role in the future of the American spaceflight, it also provides a critical test for technology expected to figure prominently in revamping the country's ailing manufacturing industry.

NASA's Marshall Space Flight Center in Huntsville, Ala., is testing an approach called selective laser melting (SLM) to create parts for the J-2X and RS-25 rocket engines that will power the SLS, whose maiden voyage is slated for 2017. The space agency expects SLM to simplify the process of making certain parts and in some cases halve the cost of producing them—a huge advantage for NASA, provided the components can withstand the rigors of lifting the largest launch vehicle ever built into space.

The first version of the SLS is a 70-metric-ton rocket that will lift around 70,000 kilograms while providing 10 percent more thrust than the Saturn 5. This SLS will power the 2017 Exploration Mission 1, which will launch an unmanned Orionspacecraft on a circumlunar voyage as a precursor to Exploration Mission 2. That mission, scheduled for 2021, will use a 130-metric-ton version of the SLS to launch Orion and a crew of up to four astronauts. This second SLS will be capable of lifting more than 130,000 kilograms and provide 20 percent more thrust than the Saturn 5.

Cash-strapped NASA is counting on SLM to speed SLS's development and reduce the program's costs. SLM is a type of additive manufacturing technology, which uses computer-aided design (CAD) files to build parts layer by layer (3-D printing is perhaps the most well known example of additive manufacturing). With SLM, a finely powdered alloy is deposited in a layer as thin as 20 microns and then fused together by a focused laser beam inside a chamber containing inert gas such as argon or nitrogen. Once the laser has turned that layer into solid metal, another layer of powder is deposited and the process is repeated.

NASA is testing the viability of making engine parts from nickel-based alloys using an SLM machine with a square cubical build chamber measuring 250 millimeters on each side and a depth of 280 millimeters. These same alloys are already used to make 90 percent of the parts in the RS-25 and J-2X engines. The key difference is that the engines' current elements are forged and then milled into their final shapes. Often several pieces must be welded together to create a part.

Marshall engineers began evaluating alternative approaches to building parts for the next-generation J-2X engine a few years ago. In late 2010 they turned to SLM to create a duct for a gas generator in the engine. "The part itself is not necessarily complex—it's a [10-centimeter] in diameter duct that's bent in a U-shape," says Andy Hardin, SLS Liquid Engines Office engine integration hardware lead. However, "because of the thickness and the radius of the bend, it's very difficult to make. We were having trouble getting vendors to do this properly."

After printing the duct, the engineers set about deconstructing it to study its metallurgy and microscopic structure. They found that although the part was not as strong as a forged and milled duct, it fell within the "minimal acceptable range," Hardin says. "If you made a part [using SLM], the material properties would be degraded somewhat but not much." One structural advantage is that the part required no welding. "When you make a part out of multiple pieces, welds are always the weakest points," he adds. This opened the door for the engineers to consider using SLM to make other engine parts as well.

SLM, and additive manufacturing in general, is not a viable option for all J-2X or RS-25 engine parts. For starters, the printed parts must be small enough to fit in the machine's build chamber. And a lot more testing is required to determine whether components such as turbines, which operate under the most intense conditions, could be made properly using SLM, Hardin says. Good candidates for SLM are those with complex geometries that are difficult to make and require multiple welds to achieve those geometries. Depending on how well printed J-2X parts fare in tests, Marshall engineers hope to at some point use SLM to likewise make parts for the older RS-25, which served as the space shuttle's main engine throughout its 30-year history.

Another incentive for NASA to transition to additive-manufactured parts: their contractors are beginning to adopt the technology in their factories. "As a big customer for many of these manufacturers, we thought it was important that we understand the technology," Hardin says. NASA does not want to hold manufacturers back by failing to create specifications for parts made using SLM or some other additive process, he adds.