A southerly looking night view of the upper two-thirds of the Florida peninsula was recorded by the Expedition 26 crew aboard the International Space Station on Dec. 28, 2010. Cape Canaveral and the Kennedy Space Center are very well lighted on the Atlantic Ocean side of the peninsula to the left in this image. The Tampa-St. Petersburg area is seen on the Gulf of Mexico or right side of the frame. At bottom or in the north areas of the picture are portions of the state’s panhandle as well as cities and communities in southern Georgia.
For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1832.html
Snows are finally winding down in New England today, Dec. 27, as a powerful low pressure system brought blizzard conditions from northern New Jersey to Maine over Christmas weekend. The GOES-13 satellite captured an image of the low's center off the Massachusetts coast and saw the snowfall left behind.
The Geostationary Operational Environmental Satellite called GOES-13 captured the visible image. GOES satellites are operated by the National Oceanic and Atmospheric Administration, and NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images and animations.
As of 1:30 p.m. EST, all blizzard warnings were canceled as the low has pulled much of its snow and rain away from land areas and into the North Atlantic Ocean. The winds behind the system are now causing more problems for residents along the U.S. East coast.
Snowfall ranged from 1.5 inches in Atlanta, Georgia to more than a foot in various areas of New Jersey, New York and the New England states. Near Wallops Island, Va. where NASA has a facility, more than 11 inches of snow was reported this morning. Newark, N.J. reported 17.7 inches of snow by midnight last night. Central Park in New York City reported 12.0 inches of snow had fallen just before midnight. Providence, Rhode Island reported 7.9 inches by midnight, while Boston, Mass. reported 9.9 inches at that time. More snow fell on top of those totals during the morning hours today.
Some of those snows are visible in today's GOES-13 satellite image. Snowfall on the ground can be seen in the image over South and North Carolina, Virginia, Maryland, Delaware, eastern Pennsylvania, New Jersey, and southeastern New York. The clouds of the low obscure New England in the image.
From Maine south to the Carolinas winds are howling in excess of 30 mph, and power outages could occur as a result of the winds and the areas with the heaviest snows. The winds in Portland, Maine today are blowing from the northwest from 20 to 30 mph with gusts over 40 mph. Yesterday in Newark, N.J. sustained winds of 41 mph were reported with gusts as high as 51 mph. Going further south, the Raleigh, N.C. National Weather Service noted that sustained northwest winds of 10 to 20 mph with gusts up to 30 mph are expected today. Even further south, Atlanta, Georgia is also experiencing winds up to 20 mph today.
The winds are making clean-up efforts difficult along the east coast, but as temperatures are expected to slowly and steadily climb over the course of the week travel will become easier every day.
For more information visit http://www.nasa.gov/centers/goddard/news/features/2010/goes13-snow.html
Since its founding in 1941, NASA's Glenn Research Center in Cleveland has made invaluable contributions to aeronautics and space flight. New aircraft technology has been developed, tested, designed and fabricated at Glenn. And for much of Glenn's history, the testing of cutting-edge technology took place in the Altitude Wind Tunnel.
During its existence, the AWT played pivotal roles in myriad projects, from early astronaut training in Project Mercury to testing the Centaur rocket. It ceased operations in the 1970s and was demolished in 2009.
Although the tunnel itself is now gone, the lessons learned in the tunnel remain. And there are stories from the tunnel to be told.
The Altitude Wind Tunnel and Space Power Chambers
Bob Arrighi (Wyle Information Systems LLC) is the archivist for Glenn. His job is to archive, document and present to the public the rich history of Glenn. When the Altitude Wind Tunnel (AWT) was demolished in 2009, he was tasked with telling the tunnel's story. He has written a book, called "Revolutionary Atmosphere: The Story of the Altitude Wind Tunnel and the Space Power Chambers." Accompanying this book is a DVD, "A Tunnel Through Time: The History of NASA's Altitude Wind Tunnel." There is also a website that explores the history of the AWT. A complete online version of the book "Revolutionary Atmosphere" is available.
The tales of the tunnel can, quite literally, fill a book. Bob Arrighi gives us a preview into the book and shares a bit about his background, how the project came to be, what the process of writing the book was like, and why the topic is relevant today.
Q: What does your job entail?
Bob Arrighi: I maintain a collection of documents and other media related to the history of NASA's Glenn Research Center. I assist researchers with reference requests and in-depth research. I also identify or am assigned noteworthy historical topics and asked to document them by creating publications, websites, documentaries and multimedia pieces.
Q: How long have you been at Glenn?
Arrighi: I started at in July 2001 as a contractor for the Plum Brook Reactor Facility documentation effort. In July 2003 I assumed my current position in the Glenn History Office. Since May 2005, my time has been divided between working on documentation of the Altitude Wind Tunnel (AWT), Propulsion Systems Laboratory and other facilities for the Glenn Historic Preservation Officer and my continuing role in the History Office.
Q: How did the idea of the book come about?
Arrighi: Section 106 of the National Preservation Act states that federal agencies must work with the State Historic Preservation Officers to mitigate any significant changes to historic facilities or structures. In recent years, Glenn has demolished several of its historic facilities, and so has been required to provide the State Historic Preservation Officers with documentation of the history of each facility. The type of documentation is worked out with the State Historic Preservation Officers prior to any demolition.
Past projects have included the Plum Brook Reactor Facility and Rocket Engine Test Facility. In both cases, an outside company was hired to perform the documentation. Books, documentaries, a website and other materials were created. When outlining the efforts undertaken to fulfill the mitigation for the Altitude Wind Tunnel (AWT) and Propulsion Systems Laboratory, the work on Plum Brook Reactor Facility and Rocket Engine Test Facility served as a template. A number of products were requested. These products, created in-house, included a website, documentary, a historic engineering report and a book.
Q: What was the timeline for creating the book?
Arrighi: I started the general AWT research during the summer of 2005. A big push on the manuscript came in the summer and fall of 2007. The manuscript was submitted to NASA Headquarters in Washington for peer review in September 2008. Editing and layout were conducted throughout 2009. We received copies in June 2010.
Q: Describe the process of writing this book.
Arrighi: As I started the research, I kept an ongoing narrative of information that was used for many of the different products. As the research became more complete and some of the other products had been created, I began converting this narrative into a story by integrating quotes from interviews, photographs and anecdotes from articles, and creating chapters and sidebars. I repeatedly reviewed and rewrote the text to make it more interesting and easier to grasp. After incorporating comments from the peer reviewers, I began working with Nancy O'Bryan (Wyle Information Systems LLC) and Kelly Shankland (Wyle Information Systems LLC) in the Publishing Department at Glenn. We worked on editing the text and laying out the chapters. This process, which included creating the index, formatting the citations and working on the cover art, took about a year to complete.
Q: Describe what the book is about.
Arrighi: The book tells the history of the Altitude Wind Tunnel, or AWT. For years, the AWT was not only Glenn's premier facility, but also the only tunnel in the country that could test engines in altitude conditions. In the late 1950s it was modified so that its interior could be used for several altitude tests and astronaut training for Project Mercury. In 1961 the facility was converted into two large test chambers and used for numerous different types of tests for the Centaur second-stage rocket. The facility was closed in the mid-1970s. A bid to restore the facility to its original wind tunnel function in the early 1980s failed. The tunnel was eventually demolished in 2009.
Q: Why did you think it was important to write this book?
Arrighi: Glenn has a rich history that includes many significant accomplishments and a high level of technical expertise. The AWT story provides insight into the center's history from its very inception through the turbojet revolution, to the early manned space program and into recent years. The AWT demonstrates the significance of modifying a facility to stay relevant, the importance of the center's technical staff and the accomplishments of Abe Silverstein, a former Glenn center director who was very instrumental in the creation of NACA and NASA wind tunnels.
Q: How is the subject material of your book relevant to the general public?
Arrighi: Although it is impossible to write a book about a wind tunnel without getting into some technical detail, I tried to focus on the staff who were involved, and what was happening contextually. The AWT story presents many of the center's accomplishments to the public, many which have never been shared before.
Q: What is one of the most interesting things in the book?
Arrighi: I learned a tremendous amount about NACA, Glenn, jet engines, liquid hydrogen, and many other topics. Probably the most rewarding aspect was talking with or reading interview transcripts from former employees. These fill the cracks that reports, newspaper articles and other sources leave open. In almost every case, two themes arose in these interviews: the importance and skill of the mechanics and technicians and Abe Silverstein's role in guiding the center and agency for decades.
Read the Book, Watch the DVD
There are several ways to purchase a printed copy of "Revolutionary Atmosphere: The Story of the Altitude Wind Tunnel and the Space Power Chambers."
For more information visit http://www.nasa.gov/centers/glenn/about/bios/revolution_atmosphere.html
The first time anyone installed a main engine in a space shuttle in 1980, it took three days and prompted a series of changes that quickly became standard practice.
"The first one, it was, 'There's the orbiter, go put a motor in it,'" recalled Robert "Bob" Rysdyk, a lead engine technician for Pratt & Whitney Rocketdyne who helped install that first engine.
There were laser instruments galore marking off all sorts of measurements as technicians tried to set the first engine carefully inside shuttle Columbia's aft compartment.
Rysdyk credits engineer Roy Austin with working out a simple solution.
"He actually went down to the janitor's closet and cut two broomsticks the same length and used those to align the pump to the orbiter," Rysdyk said.
Thirty years and more than 130 missions later, Rysdyk was part of the team that installed what’s expected to be the last set of main engines in a shuttle, this time in Atlantis. It took less than four hours and the team used the same measurements that Austin came up with when he cut the broom handles.
Two years before that first installation, Rysdyk said he had no space program ambitions.
"I was working on four-cylinder airplane engines that would fit on a desk," Rysdyk said. "I got recruited from my next door neighbor who was an engineer out here in '79. Literally, my application was a sheet of notebook paper with my name and what I did on it. I got a job interview and hired within a week."
Michael Kerasotis, a quality inspector with Pratt & Whitney Rocketdyne, came to Kennedy in 1979 as part of a summer program. He started working on the shuttle's tiles but migrated to engine work within a couple years of Columbia's first launch.
"This has been the longest summer ever," Kerasotis joked. "We got a pass to come out here and see (the shuttle). I never thought I'd be working on it."
One of the most carefully choreographed aspects of preparing a shuttle for launch involves placing three 7,700 pound main engines into the back of the spacecraft.
It takes eight people and a lot of patience.
The machinery involved starts with a cone-shaped fitting specially made to handle a main engine. Because the engines face slightly up toward the rudder, they have to be installed at an angle. So the fitting is welded to a sliding rack. The rack and fitting are, in turn, positioned on the front of a huge forklift known as the "Hyster" for the engine installation.
The engine installer, forklift and the technicians who oversee an installation preach careful control anytime an engine is on the move.
The installer has seen very few changes since it was brought to Kennedy in the late 70s, Rysdyk said.
"Every other piece of ground support equipment has gone through a lot of changes," he said. "That thing right there is almost exactly like it was in 1978."
The machinery also got a lot more use than designers thought it would, although it has held up just fine. That's because the shuttle's main engines originally were not expected to be removed after each flight. Instead, the main engines are taken out soon after a shuttle returns so their components can be inspected closely and without the engines in the way, processing for the Orbiter is safer and quicker. The main engines for the initial five missions were inspected in-place without removal from Columbia.
"We literally in the first few operational flights after that, used up the whole design life of the engine installer," Rysdyk said.
More than equipment changed, too. One of the most common sights during an installation process is an engineer sitting on top of the engine installer in a posture reminiscent of "Dr. Strangelove."
"That came about by accident," Rysdyk said.
Basically, the engineer leading the first engine installation ran out of room to stand, so he hopped up on the installer to get out of the way. Although some folks didn't want anyone on top of the installer for fear of falling, the advantages became apparent instantly.
"Suddenly, he sees he can see a lot better up there," Rysdyk said. "He can run the job better."
Both Rysdyk and Kerasotis said the stress of handling the machinery regularly on tight schedules and in changing situations gives the engine teams a strong sense of camaraderie.
"There are personal sacrifices," Rysdyk said. "Kids' rehearsals go out the window, trips go out the window, birthdays go out the window because what's important is that this gets done."
Some of the launches during the early part of the Space Shuttle Program were scrubbed a few seconds before liftoff, after the main engines had ignited but were shut down for a problem. Called a "pad abort," the situation meant a mandatory engine change at the launch pad, with the shuttle in its launch position.
"If you have a pad abort, you're life comes to a stop except for that engine," Rysdyk said. "There were nights when you'd come in at midnight and come out at noon. There was nothing but, 'Get it done.'"
While the vast majority of installations have been completed in the confines of an orbiter processing facility, replacing an engine at the launch pad requires just as much precision, but in an environment that is hardly hospitable, especially in the winter.
"That flame trench works both ways," Kerasotis said, explaining that just as the flame trench funnels fire and exhaust away from the shuttle at launch, it collects frigid air from the north in the winter and shoots it up into the bottom of the shuttle stack.
The workers endure the harsh environment because the engines are not just important, they are incredibly complex machines that are at once more than 99 percent efficient and unforgiving. In other words, the technicians know they are one of the last to touch the engines to ensure mission success and no flaws in installation.
"It's never normal, but you get used to it," Rysdyk said.
For more information visit http://www.nasa.gov/mission_pages/shuttle/behindscenes/engineinstall.html
Since its founding in 1941, NASA's Glenn Research Center in Cleveland has made invaluable contributions to aeronautics and space flight. New aircraft technology has been developed, tested, designed and fabricated at Glenn. And for much of Glenn's history, the testing of cutting-edge technology took place in the Altitude Wind Tunnel.
The Altitude Wind Tunnel, or AWT, was built in Cleveland in 1944. The huge structure, which could accommodate a full-sized airplane within the tunnel, was the first of its kind to accurately simulate a variety of realistic flight conditions. Researchers could investigate the effects of high speeds and varying pressures, temperatures and elevations on aircraft by using this tunnel.
During its existence, the AWT played pivotal roles in myriad projects, from early astronaut training in Project Mercury to testing the Centaur rocket. It ceased operations in the 1970s and was demolished in 2009.
Although the tunnel itself is now gone, the lessons learned in the tunnel remain. And there are stories from the tunnel to be told.
The Altitude Wind Tunnel and Space Power Chambers
Bob Arrighi (Wyle Information Systems LLC) is the archivist for Glenn. His job is to archive, document and present to the public the rich history of Glenn. When the Altitude Wind Tunnel (AWT) was demolished in 2009, he was tasked with telling the tunnel's story. He has written a book, called "Revolutionary Atmosphere: The Story of the Altitude Wind Tunnel and the Space Power Chambers." Accompanying this book is a DVD, "A Tunnel Through Time: The History of NASA's Altitude Wind Tunnel." There is also a website that explores the history of the AWT. A complete online version of the book "Revolutionary Atmosphere" is available.
The tales of the tunnel can, quite literally, fill a book. Bob Arrighi gives us a preview into the book and shares a bit about his background, how the project came to be, what the process of writing the book was like, and why the topic is relevant today.
Q: What does your job entail?
Bob Arrighi: I maintain a collection of documents and other media related to the history of NASA's Glenn Research Center. I assist researchers with reference requests and in-depth research. I also identify or am assigned noteworthy historical topics and asked to document them by creating publications, websites, documentaries and multimedia pieces.
Q: How long have you been at Glenn?
Arrighi: I started at in July 2001 as a contractor for the Plum Brook Reactor Facility documentation effort. In July 2003 I assumed my current position in the Glenn History Office. Since May 2005, my time has been divided between working on documentation of the Altitude Wind Tunnel (AWT), Propulsion Systems Laboratory and other facilities for the Glenn Historic Preservation Officer and my continuing role in the History Office.
Q: How did the idea of the book come about?
Arrighi: Section 106 of the National Preservation Act states that federal agencies must work with the State Historic Preservation Officers to mitigate any significant changes to historic facilities or structures. In recent years, Glenn has demolished several of its historic facilities, and so has been required to provide the State Historic Preservation Officers with documentation of the history of each facility. The type of documentation is worked out with the State Historic Preservation Officers prior to any demolition.
Past projects have included the Plum Brook Reactor Facility and Rocket Engine Test Facility. In both cases, an outside company was hired to perform the documentation. Books, documentaries, a website and other materials were created. When outlining the efforts undertaken to fulfill the mitigation for the Altitude Wind Tunnel (AWT) and Propulsion Systems Laboratory, the work on Plum Brook Reactor Facility and Rocket Engine Test Facility served as a template. A number of products were requested. These products, created in-house, included a website, documentary, a historic engineering report and a book.
Q: What was the timeline for creating the book?
Arrighi: I started the general AWT research during the summer of 2005. A big push on the manuscript came in the summer and fall of 2007. The manuscript was submitted to NASA Headquarters in Washington for peer review in September 2008. Editing and layout were conducted throughout 2009. We received copies in June 2010.
Q: Describe the process of writing this book.
Arrighi: As I started the research, I kept an ongoing narrative of information that was used for many of the different products. As the research became more complete and some of the other products had been created, I began converting this narrative into a story by integrating quotes from interviews, photographs and anecdotes from articles, and creating chapters and sidebars. I repeatedly reviewed and rewrote the text to make it more interesting and easier to grasp. After incorporating comments from the peer reviewers, I began working with Nancy O'Bryan (Wyle Information Systems LLC) and Kelly Shankland (Wyle Information Systems LLC) in the Publishing Department at Glenn. We worked on editing the text and laying out the chapters. This process, which included creating the index, formatting the citations and working on the cover art, took about a year to complete.
Q: Describe what the book is about.
Arrighi: The book tells the history of the Altitude Wind Tunnel, or AWT. For years, the AWT was not only Glenn's premier facility, but also the only tunnel in the country that could test engines in altitude conditions. In the late 1950s it was modified so that its interior could be used for several altitude tests and astronaut training for Project Mercury. In 1961 the facility was converted into two large test chambers and used for numerous different types of tests for the Centaur second-stage rocket. The facility was closed in the mid-1970s. A bid to restore the facility to its original wind tunnel function in the early 1980s failed. The tunnel was eventually demolished in 2009.
Q: Why did you think it was important to write this book?
Arrighi: Glenn has a rich history that includes many significant accomplishments and a high level of technical expertise. The AWT story provides insight into the center's history from its very inception through the turbojet revolution, to the early manned space program and into recent years. The AWT demonstrates the significance of modifying a facility to stay relevant, the importance of the center's technical staff and the accomplishments of Abe Silverstein, a former Glenn center director who was very instrumental in the creation of NACA and NASA wind tunnels.
Q: How is the subject material of your book relevant to the general public?
Arrighi: Although it is impossible to write a book about a wind tunnel without getting into some technical detail, I tried to focus on the staff who were involved, and what was happening contextually. The AWT story presents many of the center's accomplishments to the public, many which have never been shared before.
Q: What is one of the most interesting things in the book?
Arrighi: I learned a tremendous amount about NACA, Glenn, jet engines, liquid hydrogen, and many other topics. Probably the most rewarding aspect was talking with or reading interview transcripts from former employees. These fill the cracks that reports, newspaper articles and other sources leave open. In almost every case, two themes arose in these interviews: the importance and skill of the mechanics and technicians and Abe Silverstein's role in guiding the center and agency for decades.
Read the Book, Watch the DVD
There are several ways to purchase a printed copy of "Revolutionary Atmosphere: The Story of the Altitude Wind Tunnel and the Space Power Chambers."
For more information visit http://www.nasa.gov/centers/glenn/about/bios/revolution_atmosphere.html
The Deep Space Network (DSN) consists of three communications complexes: in Goldstone, Calif.; Madrid, Spain; and Canberra, Australia. The 70-meter antennas are more than 40 years old and are showing signs of surface deterioration from constant use. Additional 34-meter antennas are being installed in Canberra in the first phase; subsequent phases will install additional 34-meter antennas in Goldstone and Madrid.
The 34-meter beam waveguide antennas are essential to keep communications flowing smoothly as NASA's fleet of spacecraft continues to expand. In addition, the waveguide design of the antennas provides easier access for maintenance and future upgrades, because sensitive electronics are housed in a below-the-ground pedestal equipment room, instead of in the center of the dish.
"As a result of several studies, it was determined that arrays of 34-meter beam waveguide antennas were the best solution to long-term continuation of DSN 70-meter capabilities," said Miguel Marina, who manages the 70-meter replacement task force at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The new antennas are critical communication resources for all current and future NASA missions."
NASA expects to complete the building of the first two 34-meter antennas in Canberra by 2016. They will be named Deep Space Stations 35 and 36. Deep Space Station 35 is due to be online in 2014, and Deep Space Station 36 is expected to follow in 2016.
In 1958, NASA established the Deep Space Network as a separately managed and operated communications facility to accommodate all deep space missions. This avoided the need for each flight project to acquire its own specialized space communications network. During the Apollo period (1967-1972), these stations supported America's missions to the moon, including the historic first manned landing. The Goldstone antenna, in particular, captured Neil Armstrong's words and sent them on to American television sets while the images came through another antenna.
The Deep Space Network is now sending commands to numerous robotic spacecraft, such as NASA's Mars Exploration Rovers, the Spitzer Space Telescope, the Saturn explorer Cassini and the two Voyager spacecraft, which are near the edge of the solar system.
JPL, a division of the California Institute of Technology in Pasadena, manages the Deep Space Network for NASA Headquarters, Washington.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-429
From space, NASA satellites record the change of seasons. Satellite images show large parts of the landscape at one time. They help scientists study regional patterns on Earth. These images also help show bigger changes that may occur over many years.
A new slide show, "The Change of Seasons: Views from Space," shows some of the ways seasonal change affects our planet, and invites you to share your own photos of seasonal change where you live: http://www.jpl.nasa.gov/education/seasons.cfm .
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-425
For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1825.html
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-421
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-419
Saturn is at the center, with the red "donut" representing the distribution of dense neutral gas outside Saturn's icy rings. Beyond this region, energetic ions populate the plasma sheet to the dayside magnetopause filling the faintly sketched magnetic flux tubes to higher latitudes and contributing to the ring current. The plasma sheet thins gradually toward the nightside. The view is from above Saturn’s equatorial plane, which is represented by grid lines. The moon Titan’s location is shown for scale. The location of the bow shock is marked, as is the flow of the deflected solar wind in the magnetosheath.
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, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The magnetospheric imaging instrument was designed, built and is operated by an international team lead by the Applied Physics Laboratory of the Johns Hopkins University, Laurel, Md.
For more information visit http://www.nasa.gov/mission_pages/cassini/multimedia/pia10084.html
Now hurtling toward interstellar space some 17.4 billion kilometers (10.8 billion miles) from the sun, Voyager 1 has crossed into an area where the velocity of the hot ionized gas, or plasma, emanating directly outward from the sun has slowed to zero. Scientists suspect the solar wind has been turned sideways by the pressure from the interstellar wind in the region between stars.
The event is a major milestone in Voyager 1's passage through the heliosheath, the turbulent outer shell of the sun's sphere of influence, and the spacecraft's upcoming departure from our solar system.
"The solar wind has turned the corner," said Ed Stone, Voyager project scientist based at the California Institute of Technology in Pasadena, Calif. "Voyager 1 is getting close to interstellar space."
Our sun gives off a stream of charged particles that form a bubble known as the heliosphere around our solar system. The solar wind travels at supersonic speed until it crosses a shockwave called the termination shock. At this point, the solar wind dramatically slows down and heats up in the heliosheath.
Launched on Sept. 5, 1977, Voyager 1 crossed the termination shock in December 2004 into the heliosheath. Scientists have used data from Voyager 1's Low-Energy Charged Particle Instrument to deduce the solar wind's velocity. When the speed of the charged particles hitting the outward face of Voyager 1 matched the spacecraft's speed, researchers knew that the net outward speed of the solar wind was zero. This occurred in June, when Voyager 1 was about 17 billion kilometers (10.6 billion miles) from the sun.
Because the velocities can fluctuate, scientists watched four more monthly readings before they were convinced the solar wind's outward speed actually had slowed to zero. Analysis of the data shows the velocity of the solar wind has steadily slowed at a rate of about 20 kilometers per second each year (45,000 mph each year) since August 2007, when the solar wind was speeding outward at about 60 kilometers per second (130,000 mph). The outward speed has remained at zero since June.
The results were presented today at the American Geophysical Union meeting in San Francisco.
"When I realized that we were getting solid zeroes, I was amazed," said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and senior staff scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "Here was Voyager, a spacecraft that has been a workhorse for 33 years, showing us something completely new again."
Scientists believe Voyager 1 has not crossed the heliosheath into interstellar space. Crossing into interstellar space would mean a sudden drop in the density of hot particles and an increase in the density of cold particles. Scientists are putting the data into their models of the heliosphere's structure and should be able to better estimate when Voyager 1 will reach interstellar space. Researchers currently estimate Voyager 1 will cross that frontier in about four years.
"In science, there is nothing like a reality check to shake things up, and Voyager 1 provided that with hard facts," said Tom Krimigis, principal investigator on the Low-Energy Charged Particle Instrument, who is based at the Applied Physics Laboratory and the Academy of Athens, Greece. "Once again, we face the predicament of redoing our models."
A sister spacecraft, Voyager 2, was launched in Aug. 20, 1977 and has reached a position 14.2 billion kilometers (8.8 billion miles) from the sun. Both spacecraft have been traveling along different trajectories and at different speeds. Voyager 1 is traveling faster, at a speed of about 17 kilometers per second (38,000 mph), compared to Voyager 2's velocity of 15 kilometers per second (35,000 mph). In the next few years, scientists expect Voyager 2 to encounter the same kind of phenomenon as Voyager 1.
The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-415
The contract will support planning, coordination, preparation and packing of standardized containers for cargo missions to the station by international partner and commercial cargo vehicles. Lockheed Martin will process flight crew equipment including clothing and personal hygiene items, housekeeping items, audio and video equipment, laptop computers, batteries and crew survival equipment. The contract also includes provisions to support similar services for future vehicles to the station.
A three-month phase-in period and the three-year basic period of the cost-plus-award-fee contract have a total estimated value of $85 million. The contract phase-in period begins Jan. 1, 2011. The basic period extends from April 1, 2011, through March 31, 2014. Exercising four one-year extension options worth a total of $86 million would bring the contract value to $171 million.
Work on the contract will be performed at NASA's Johnson Space Center in Houston and other Texas locations. Major Texas subcontractors include Bastion Technologies and Dittmar Associates, both of Houston; GHG Corp. of Webster; LZ Technology in Alvin; Rothe Enterprises in San Antonio; and the University of Texas at El Paso.
For more information visit http://www.nasa.gov/home/hqnews/2010/dec/HQ_C10-079_ISS_Cargo_Services.html
The event drew more than 260 students and teachers representing 16 schools from throughout Southern California. This year's challenge was to build a unique device capable of lifting an officially supplied ping-pong ball and cause the ball to touch and hold against a ceiling located 2 meters (about 6.6 feet) above ground. The winner completed this task in the fastest time.
A total of 19 student teams competed side-by-side with 15 teams that included JPL engineers. There was a tie for the winning JPL team between P.C. Chen and David Van Buren, while second place went to Richard Goldstein and third place to Bob Krylo.
The requirements this year: The devices had to be initiated by a single operation (cut a string, flick a switch, etc.), use safe energy sources, and could be no larger, prior to the start of the task than 50 centimeters (19.7 inches) high by 1.2 meters (about 3.9 feet) wide by 1.2 meters (about 3.9 feet) long. The devices had to be made from non-toxic and safe materials.
The rules change each year, but the results remain consistent: Students challenge themselves, solve problems and appreciate that math, science and engineering can be fun.
When asked for the key to their success, Yunis Karaca, the team's mentor replied, "We first brainstormed and then I let the kids use their imagination."
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-414
The video called "Got Your Back" is part of an on-going video series about the Webb telescope called "Behind the Webb." It was produced at the Space Telescope Science Institute (STScI) in Baltimore, Md. and takes viewers behind the scenes with scientists and engineers who are creating the Webb telescope's components. During the 3 minute and 12 second video, STScI host Mary Estacion interviewed people involved in the project at Ball Aerospace in Boulder, Colo. and showed the actuators in action.
The Webb telescope will study every phase in the history of our universe, ranging from the first luminous glows after the big bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own solar system. Measuring the light this distant light requires a primary mirror 6.5 meters (21 feet 4 inches) across – six times larger than the Hubble Space telescope’s mirror!
Launching a mirror this large into space isn’t feasible. Instead, Webb engineers and scientists innovated a unique solution – building 18 mirrors that will act in unison as one large mirror. These mirrors are packaged together into three sections that fold up - much easier to fit inside a rocket. Each mirror is made from beryllium and weighs approximately 20 kilograms (46 pounds). Once in space, getting these mirrors to focus correctly on faraway galaxies is another challenge entirely. Actuators, or tiny mechanical motors, provide the answer to achieving a single perfect focus.
The primary and secondary mirror segments are both moved by six actuators that are attached to the back of the mirrors. The primary segment has an additional actuator at the center of the mirror that adjusts its curvature. The third mirror segment remains stationary.
Lee Feinberg, Webb Optical Telescope Element Manager at NASA's Goddard Space Flight Center in Greenbelt, Md. explained "Aligning the primary mirror segments as though they are a single large mirror means each mirror is aligned to 1/10,000th the thickness of a human hair. This alignment has to be done at 50 degrees above absolute zero! What's even more amazing is that the engineers and scientists working on the Webb telescope literally had to invent how to do this."
With the actuators in place, Brad Shogrin, Webb Telescope Manager at Ball Aerospace, Boulder, Colo, details the next step: attaching the hexapod (meaning six-footed) assembly and radius of curvature subsystem (ROC). "Radius of curvature" refers to the distance to the center point of the curvature of the mirror. Feinberg added "To understand the concept in a more basic sense, if you change that radius of curvature, you change the mirror's focus."
The "Behind the Webb" video series is available in HQ, large and small Quicktime formats, HD, Large and Small WMV formats, and HD, Large and Small Xvid formats.
For more information visit http://www.nasa.gov/topics/technology/features/webb-actuator.html
About the Chats
You have two opportunities to learn more about the Geminids from meteor experts based at NASA's Marshall Space Flight Center. On Monday, Dec. 13 from 3:00 to 4:00 p.m. EST, meteor experts Danielle Moser and Rhiannon Blaauw will answer your questions, then you can stay "up all night" to observe the Geminids with NASA astronomer Bill Cooke. Have the coffee ready, then join them online from 11:00 p.m. to 5:00 a.m. EST as the Geminids peak in the skies over Earth.
Joining the chats is easy. Simply return to this page a few minutes before each of the chat start times list above. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated, then ask your questions. Here's to a spectacular viewing!
Live Camera Viewing of the Geminids
December can be an uncertain month for weather, but clouds and meteor-watching don't mix. To assist in the weather-workaround, NASA and meteor-observing partners are working on a network of live Web cameras that will watch the skies from different locations. Links for the live feeds will be available on this page on the night of Dec. 13-14 -- just in case your local weather is uncooperative or you decide not to brave the chilly December evening.
More About the Geminids
Geminids are pieces of debris from an object called 3200 Phaethon. Long thought to be an asteroid, Phaethon is now classified as an extinct comet. Basically it is the rocky skeleton of a comet that lost its ice after too many close encounters with the sun. Earth runs into a stream of debris from 3200 Phaethon every year in mid-December, causing meteors to fly from the constellation Gemini. When the Geminids first appeared in the late 19th century, shortly before the U.S. Civil War, the shower was weak and attracted little attention. There was no hint that it would ever become a major display.
For more information visit http://www.nasa.gov/connect/chat/geminids2010.html
During a routine inspection this week, SpaceX engineers observed two small cracks in the rocket's second stage engine nozzle. SpaceX completed repairs to the cracked nozzle Tuesday.
For more information visit http://www.nasa.gov/home/hqnews/2010/dec/HQ_M10-170_Falcon_9_Launch.html
Recent graduates who work for JPL launched a sounding rocket 120 kilometers (75 miles) above Earth's surface on Monday, Dec. 6. The rocket flew from the U.S. Army's White Sands Missile Range in New Mexico, with four cameras on board. The cameras recorded real-time ground imagery throughout the flight, both after launch as the rocket climbed beyond the atmosphere, and during its descent back to White Sands. Those data will be compared with existing maps to develop terrain-modeling algorithms. This project will improve precision landing for future missions to Mars and other locations.
Members of the Phaeton group, a rapid-training program for early career hires at JPL, submitted a proposal to NASA's Hands-on-Project Experience. The program, created by NASA in November 2008, aims to give rising engineers, scientists and others the opportunity to move a small mission from concept to launch to post-flight analysis. In May 2009, the Phaeton group was selected to move forward with their proposed project, called Terrain Relative Navigation and Employee Development, which they refer to as Trained.
"The best thing about the Phaeton program is taking a project from the idea to launch and taking ownership of the decisions," said Elvis Merida, the Trained mission assurance manager. "I'm always making a conscious effort to educate myself, which is why I applied for the Phaeton program." Merida, who received a bachelor's and master's degree from California State University, Northridge, is currently working toward a second master's degree, in electrical engineering, from California State University, Los Angeles.
The Phaeton program consists of about 40 early career hires at JPL working on three small-payload projects with a life cycle of about two to three years. Each team member is matched with an experienced JPL mentor to guide in technical and leadership development skills.
"The program was designed for early-career hires, but I'm actually learning from it," said Johnny Kwok, who oversees the grads as Phaeton program manager at JPL. "Through their eyes, I'm learning about what they're experiencing, and they have the opportunity to touch all the pieces of the life development process."
With the Dec. 6 launch, the Trained program participants have completed this portion of the early-career hire experience and will move on to other career opportunities at JPL. When asked if he feels a sense of relief from completing such an important and demanding project, Merida said, "I don't feel relief. I feel as though I'm just beginning."
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-408
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of ANWR on July 25, 2010. Thick white lines delineate refuge boundaries, and thin white lines separate areas within the park. Running roughly east west, the rugged Brooks Range spans the middle part of the park. North of the Brooks Range lies tundra, and south of the range lies forest dominated by spruce trees.
The northernmost part of ANWR is tundra-covered coastal plain. Area 1002 derives its name from a section of the Alaska National Interest Lands Conservation Act, which the U.S. Congress passed in 1980. The act required an assessment of the area’s biodiversity, as well as studies on the potential effects of development, and oil and gas exploration.
ANWR is open to the public year round but the refuge is not easy to reach. Visitors must fly, boat, or hike to ANWR, and hikers must navigate the refuge’s terrain without the aid of established trails. Snow and ice dominate the landscape for as much as nine months out of every year, and from mid-November to mid-January, the Sun stays below the horizon. From late April to mid-August, however, visitors to ANWR can enjoy continuous sunlight and fields of wildflowers.
For more information visit http://earthobservatory.nasa.gov/IOTD/view.php?id=47520&src=imgrss
The nanotech-based material now being developed by a team of 10 technologists at the NASA Goddard Space Flight Center in Greenbelt, Md., is a thin coating of multi-walled carbon nanotubes — tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair. Nanotubes have a multitude of potential uses, particularly in electronics and advanced materials due to their unique electrical properties and extraordinary strength. But in this application, NASA is interested in using the technology to help suppress errant light that has a funny way of ricocheting off instrument components and contaminating measurements.
"This is a technology that offers a lot of payback," said engineer Leroy Sparr, who is assessing its effectiveness on the Ocean Radiometer for Carbon Assessment (ORCA), a next-generation instrument that is designed to measure marine photosynthesis. "It's about 10 times better than black paint" typically used by NASA instrument designers to suppress stray light, he said.
The technology works because of its super-absorption abilities. The nanotubes themselves are packed vertically much like a shag rug. The tiny gaps between the tubes absorb 99.5 percent of the light that hits them. In other words, very few photons are reflected off the carbon-nanotube coating, which means that stray light cannot reflect off surfaces and interfere with the light that scientists actually want to measure. The human eye sees the material as black because only a small fraction of light reflects off the material.
The team began working on the technology in 2007. Unbeknownst to the group, the New York-based Rensselaer Polytechnic Institute also had initiated a similar effort and announced in 2008 that its researchers had developed the darkest carbon nanotube-based material ever made — more than three times darker than the previous record. "Our material isn't quite as dark as theirs," said John Hagopian, the principal investigator leading the development team. "But what we're developing is 10 times blacker than current NASA paints that suppress system stray light. Furthermore, it will be robust for space applications," he said.
That is an important distinction, said Carl Stahle, assistant chief of technology for Goddard's Instrument Systems and Technology Division. Not all technology can be used in space because of the harsh environmental conditions encountered there. "That's the real strength of this effort," Stahle said. "The group is finding ways to apply new technology and fly it on our instruments."
Big Breakthrough
The breakthrough was the discovery of a highly adhesive underlayer material upon which to grow the carbon nanotubes, which are just a few tens of nanometers in diameter. To grow carbon nanotubes, materials scientists typically apply a catalyst layer of iron to an underlayer on the silicon substrate. They then heat the material in an oven to about 750° C (1,382° F). While heating, the material is bathed in carbon-containing feedstock gas.
Stephanie Getty, the materials scientist on Hagopian's team, varied the underlayer as well as the thickness of the catalyst materials to create carbon nanotubes that not only absorb light, but also remain fixed to the material upon which they are grown. As a result, they are more durable and less likely to scratch off. The team also has grown durable nanotube coatings on titanium, a better structural material for space use. The team now is fine-tuning production techniques to assure consistent quality and light-suppression capabilities, Hagopian said.
New Capabilities Added
Should the team prove the material's suitability in space, the material would provide real benefits to instrument developers, Hagopian added.
Currently, instrument developers apply black paint to baffles and other components to reduce stray light. Because reflectance tests have shown the coating to be more effective than paint, instrument developers could grow the carbon nanotubes on the components themselves, thereby simplifying instrument designs because fewer baffles would be required. To accommodate larger components, the team now is installing a six-inch furnace to grow nanotubes on components measuring up to five inches in diameter. And under a NASA R&D award, the team also is developing a separate technique to create sheets of nanotubes that could be applied to larger, non-conforming surfaces.
In addition to simplifying instrument design, the technology would allow scientists to gather hard-to-obtain measurements because of limitations in existing light-suppression techniques or to gather information about objects in high-contrast areas, including planets in orbit around other stars, Hagopian said.
The ORCA team, which is fabricating and aligning an instrument prototype, is the first to actually apply and test the technology. The instrument is the front-runner for the proposed Aerosol/Cloud/Ecosystems (ACE) mission and requires robust light-suppression technologies because more than 90 percent of the light gathered by the instrument comes from the atmosphere. Therefore, the team is looking for a technique to suppress the light so that it doesn't contaminate the faint signal the team needs to retrieve.
"It's been an issue with all the (ocean sensors) we've flown so far," said ORCA Principal Investigator Chuck McClain.
Working with the ORCA team, Hagopian's group grew the coating on a slit, the conduit through which all light will pass on ORCA. "Having an efficient absorber is critical and the nanotubes could provide the solution," McClain said. "Right now, it looks promising," Sparr added. "If I can support them and they can continue advancing the technology so that it can be applied to other spacecraft components, it could be a very important development for NASA."
Goddard Chief Technologist Peter Hughes agrees, and, in fact, selected Hagopian and his team to receive his organization’s 2010 "Innovator of the Year" award. "Our job is to develop and advance new technology that will ultimately result in better scientific measurements. Goddard has a well-deserved reputation for creating technologies that enhance instrument performance because we are adept at quickly infusing emerging technology for specific spaceflight applications. John’s team demonstrated that key strength. And in doing so, he’s leading the way in NASA’s quest to bring about a new level of scientific discovery," Hughes said.
For more information visit http://www.nasa.gov/topics/technology/features/new-nano.html
NASA's Cassini spacecraft successfully dipped near the surface of Saturn's moon Enceladus on Nov. 30. Though Cassini's closest approach took it to within about 48 kilometers (30 miles) of the moon's northern hemisphere, the spacecraft also captured shadowy images of the tortured south polar terrain and the brilliant jets that spray out from it.
Many of the raw images feature darkened terrain because winter has descended upon the southern hemisphere of Enceladus. But sunlight behind the moon backlights the jets of water vapor and icy particles. In some images, the jets line up in rows, forming curtains of spray.
The Enceladus flyby was the 12th of Cassini's mission, with the spacecraft swooping down around 61 degrees north latitude. This encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission. (Cassini's closest-ever approach to Enceladus occurred in October 2008, when the spacecraft dipped to an altitude of 25 kilometers, or 16 miles.)
Among the observations Cassini made during this Enceladus flyby, the radio science subsystem collected gravity measurements to understand the moon's interior structure, and the fields and particles instruments sampled the charged particle environment around the moon.
About two days before the Enceladus flyby, Cassini also passed the sponge-like moon Hyperion, beaming back intriguing images of the craters on its surface. The flyby, at 72,000 kilometers (45,000 miles) in altitude, was one of the closest approaches to Hyperion that Cassini has made.
Scientists are still working to analyze the data and images collected during the flybys.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory manages the project for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-405
More than one million people have watched assembly and testing of NASA's next Mars rover via a live webcam since it went online in October.
NASA's Mars Science Laboratory, also known as the Curiosity rover, is being tested and assembled in a clean room at the agency's Jet Propulsion Laboratory in Pasadena, Calif. The webcam, affectionately dubbed "Curiosity Cam," shows engineers and technicians clad in head-to-toe white smocks working on the rover.
Metrics from the webcam's hosting platform, Ustream, showed more than one million unique viewers spent more than 400,000 hours watching Curiosity Cam between Oct. 21 and Nov. 23. There have been more than 2.3 million viewer sessions.
The camera is mounted in the viewing gallery of the Spacecraft Assembly Facility at JPL. While the gallery is a regular stop on JPL's public tour, Curiosity Cam allows visitors from around the world to see NASA engineers at work without traveling to Pasadena.
Viewers from Chile, Japan, Turkey, Spain, Mexico and the United Kingdom have sent good wishes and asked questions in the chat box that accompanies the Curiosity Cam webstream. At scheduled times, viewers can interact with each other and JPL staff. The chat schedule is updated weekdays at http://www.ustream.tv/nasajpl.
Months of assembly and testing remain before the car-sized rover is ready for launch from Cape Canaveral, Fla. The rover and spacecraft components will ship to NASA's Kennedy Space Center in Florida next spring. The launch will occur between Nov. 25 and Dec. 18, 2011. Curiosity will arrive on Mars in August 2012.
The rover is one of the most technologically challenging interplanetary missions ever designed. Curiosity is engineered to drive longer distances over rougher terrain than previous Mars rovers. It will carry a science payload 10 times the mass of instruments on NASA's Spirit and Opportunity rovers. Curiosity will investigate whether the landing region had environments favorable for supporting microbial life. It will also look for environments that have been favorable for preserving evidence about whether life existed.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-401
Russian cosmonaut Yurchikhin, the Soyuz commander, was at the controls of the spacecraft as it undocked at 8:23 p.m. EST from the station's Rassvet module. The trio landed at 11:46 p.m. (10:46 a.m. on Nov. 26 local time) at a site northeast of the town of Arkalyk.
Working in frigid temperatures, Russian recovery teams were on hand within minutes to help the crew exit the Soyuz vehicle and re-adjust to gravity.
The trio launched aboard the Soyuz TMA-19 spacecraft from the Baikonur Cosmodrome in Kazakhstan on June 15. As members of the Expedition 24 and 25 crews, they spent 163 days in space, 161 of them aboard the station, and celebrated the 10th anniversary of continuous human life, work and research by international crews aboard the station on Nov. 2.
During their mission, the Expedition 24 and 25 crew members worked on more than 120 microgravity experiments in human research; biology and biotechnology; physical and materials sciences; technology development; and Earth and space sciences.
The astronauts also responded to an emergency shutdown of half of the station's external cooling system and supported three unplanned spacewalks by Wheelock and Expedition 24 Flight Engineer Tracy Caldwell Dyson to replace the faulty pump module that caused the shutdown. Their efforts restored the station's critical cooling system to full function.
Yurchikhin has logged 371 total days in space, Wheelock 178 days and Walker 163 days.
The station is occupied by Expedition 26 Commander Scott Kelly and Flight Engineers Alexander Kaleri and Oleg Skripochka of the Russian Federal Space Agency. Their increment officially began when the Soyuz TMA-19 undocked.
After a busy week capped with the undocking activities Thursday, Kelly, Kaleri and Skripochka caught up on their sleep Friday. They will enjoy an off-duty weekend of routine station maintenance and daily exercise before kicking off their first workweek as a three-person crew Monday.
A new trio of Expedition 26 flight engineers, NASA astronaut Catherine Coleman, Russian cosmonaut Dmitry Kondratyev and Paolo Nespoli of the European Space Agency, will launch from the Baikonur Cosmodrome on Dec. 15. They will dock with the station and join its crew on Dec. 17.
For more information visit http://www.nasa.gov/mission_pages/station/expeditions/expedition25/exp25_landing.html
Expedition 25 Commander Doug Wheelock and Flight Engineers Shannon Walker and Fyodor Yurchikhin safely landed their Soyuz spacecraft on the Kazakhstan steppe Thursday, wrapping up a five-month stay aboard the International Space Station.
Russian cosmonaut Yurchikhin, the Soyuz commander, was at the controls of the spacecraft as it undocked at 8:23 p.m. EST from the station's Rassvet module. The trio landed at 11:46 p.m. (10:46 a.m. on Nov. 26 local time) at a site northeast of the town of Arkalyk.
Working in frigid temperatures, Russian recovery teams were on hand to help the crew exit the Soyuz vehicle and re-adjust to gravity. Yurchikhin will return to the Gagarin Cosmonaut Training Center in Star City, outside of Moscow, while Wheelock and Walker will fly directly home to Houston.
The trio launched aboard the Soyuz TMA-19 spacecraft from the Baikonur Cosmodrome in Kazakhstan on June 15. As members of the Expedition 24 and 25 crews, they spent 163 days in space, 161 of them aboard the station, and celebrated the 10th anniversary of continuous human life, work and research by international crews aboard the station on Nov. 2.
During their mission, the Expedition 24 and 25 crew members worked on more than 120 microgravity experiments in human research; biology and biotechnology; physical and materials sciences; technology development; and Earth and space sciences.
The astronauts also responded to an emergency shutdown of half of the station's external cooling system and supported three unplanned spacewalks by Wheelock and Expedition 24 Flight Engineer Tracy Caldwell Dyson to replace the faulty pump module that caused the shutdown. Their efforts restored the station's critical cooling system to full function.
Yurchikhin has logged 371 total days in space, Wheelock 178 days and Walker 163 days.
The station is occupied by Expedition 26 Commander Scott Kelly and Flight Engineers Alexander Kaleri and Oleg Skripochka of the Russian Federal Space Agency. A new trio of Expedition 26 flight engineers, NASA astronaut Catherine Coleman, Russian cosmonaut Dmitry Kondratyev and Paolo Nespoli of the European Space Agency, will launch from the Baikonur Cosmodrome on Dec. 15. They will dock with the station and join its crew on Dec. 17.
For more information visit http://www.nasa.gov/home/hqnews/2010/nov/HQ_10-312_Expedition_25_Lands.html
NASA managers have targeted space shuttle Discovery's launch for no earlier than Dec. 17. Shuttle managers determined more tests and analysis are needed before proceeding with the STS-133 mission.
As a result, the launch status meeting planned for Monday, Nov. 29, has been postponed and will be rescheduled.
The Program Requirements Control Board (PRCB) reviewed on Wednesday repairs and engineering evaluations associated with cracks on two 21-foot-long, U-shaped aluminum brackets, called stringers, on the shuttle's external tank. Managers decided the analysis and tests required to launch Discovery safely are not complete. The work will continue through next week.
The next status review by the PRCB will be Thursday, Dec. 2. If managers clear Discovery for launch on Dec. 17, the preferred time is approximately 8:51 p.m. EST.
For more information visit http://www.nasa.gov/home/hqnews/2010/nov/HQ_10-313_STS-133_Delayed.html
Cassini went into safe mode on Nov. 2, when one bit flipped in the onboard command and data subsystem computer. The bit flip prevented the computer from registering an important instruction, and the spacecraft, as programmed, went into the standby mode. Engineers have traced the steps taken by the computer during that time and have determined that all spacecraft responses were proper, but still do not know why the bit flipped.
The flyby on Nov. 30 will bring Cassini to within about 48 kilometers (30 miles) of the surface of Enceladus. At 61 degrees north latitude, this encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission. (Cassini's closest-ever approach to the surface occurred in October 2008, when it dipped to an altitude of 25 kilometers, or 16 miles.)
During the closest part of the Nov. 30 flyby, Cassini's radio science subsystem will make gravity measurements. The results will be compared with those from an earlier flyby of the Enceladus south pole to understand the moon's interior structure better. Cassini's fields and particles instruments will sample the charged particle environment around Enceladus. Other instruments will capture images in visible light and other parts of the light spectrum after Cassini makes its closest approach.
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, D.C.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-398
The research, performed in a lab at JPL in Pasadena, Calif., tested a system of lasers that would fly aboard the proposed space mission called Laser Interferometer Space Antenna, or LISA. The mission's goal is to detect the subtle, whisper-like signals of gravitational waves, which have yet to be directly observed. This is no easy task, and many challenges lie ahead.
The new JPL tests hit one significant milestone, demonstrating for the first time that noise, or random fluctuations, in LISA's laser beams can be hushed enough to hear the sweet sounds of the elusive waves.
"In order to detect gravitational waves, we have to make extremely precise measurements," said Bill Klipstein, a physicist at JPL. "Our lasers are much noisier than what we want to measure, so we have to remove that noise carefully to get a clear signal; it's a little like listening for a feather to drop in the middle of a heavy rainstorm." Klipstein is a co-author of a paper about the lab tests that appeared in a recent issue of Physical Review Letters.
The JPL team is one of many groups working on LISA, a joint European Space Agency and NASA mission proposal, which, if selected, would launch in 2020 or later. In August of this year, LISA was given a high recommendation by the 2010 U.S. National Research Council decadal report on astronomy and astrophysics.
One of LISA's primary goals is to detect gravitational waves directly. Studies of these cosmic waves began in earnest decades ago when, in 1974, researchers discovered a pair of orbiting dead stars -- a type called pulsars -- that were spiraling closer and closer together due to an unexplainable loss of energy. That energy was later shown to be in the form of gravitational waves. This was the first indirect proof of the waves, and ultimately earned the 1993 Nobel Prize in Physics.
LISA is expected to not only "hear" the waves, but also learn more about their sources -- massive objects such as black holes and dead stars, which sing the waves like melodies out to the universe as the objects accelerate through space and time. The mission would be able to detect gravitational waves from massive objects in our Milky Way galaxy as well as distant galaxies, allowing scientists to tune into an entirely new language of our universe.
The proposed mission would amount to a giant triangle of three distinct spacecraft, each connected by laser beams. These spacecraft would fly in formation around the sun, about 20 degrees behind Earth. Each one would hold a cube made of platinum and gold that floats freely in space. As gravitational waves pass by the spacecraft, they would cause the distance between the cubes, or test masses, to change by almost imperceptible amounts -- but enough for LISA's extremely sensitive instruments to be able to detect corresponding changes in the connecting laser beams.
"The gravitational waves will cause the 'corks' to bob around, but just by a tiny bit," said Glenn de Vine, a research scientist and co-author of the recent study at JPL. "My friend once said it's sort of like rubber duckies bouncing around in a bathtub."
The JPL team has spent the last six years working on aspects of this LISA technology, including instruments called phase meters, which are sophisticated laser beam detectors. The latest research accomplishes one of their main goals -- to reduce the laser noise detected by the phase meters by one billion times, or enough to detect the signal of gravitational waves.
The job is like trying to find a proton in a haystack. Gravitational waves would change the distance between two spacecraft -- which are flying at 5 million kilometers (3.1 million miles) apart -- by about a picometer, which is about 100 million times smaller than the width of a human hair. In other words, the spacecraft are 5,000,000,000 meters apart, and LISA would detect changes in that distance on the order of .000000000005 meters!
At the heart of the LISA laser technology is a process known as interferometry, which ultimately reveals if the distances traveled by the laser beams of light, and thus the distance between the three spacecraft, have changed due to gravitational waves. The process is like combining ocean waves -- sometimes they pile up and grow bigger, and sometimes they cancel each other out or diminish in size.
"We can't use a tape measure to get the distances between these spacecraft," said de Vine, "So we use lasers. The wavelengths of the lasers are like our tick marks on a tape measure."
On LISA, the laser light is detected by the phase meters and then sent to the ground, where it is "interfered" via data processing (the process is called time-delay interferometry for this reason -- there's a delay before the interferometry technique is applied). If the interference pattern between the laser beams is the same, then that means the spacecraft haven't moved relative to each other. If the interference pattern changes, then they did. If all other reasons for spacecraft movement have been eliminated, then gravitational waves are the culprit.
That's the basic idea. In reality, there are a host of other factors that make this process more complex. For one thing, the spacecraft don't stay put. They naturally move around for reasons that have nothing to do with gravitational waves. Another challenge is the laser beam noise. How do you know if the spacecraft moved because of gravitational waves, or if noise in the laser is just making it seem as if the spacecraft moved?
This is the question the JPL team recently took to their laboratory, which mimics the LISA system. They introduced random, artificial noise into their lasers and then, through a complicated set of data processing actions, subtracted most of it back out. Their recent success demonstrated that they could see changes in the distances between mock spacecraft on the order of a picometer.
In essence, they hushed the roar of the laser beams, so that LISA, if selected for construction, will be able to hear the universe softly hum a tune of gravitational waves.
Other authors of the paper from JPL are Brent Ware; Kirk McKenzie; Robert E. Spero and Daniel A. Shaddock, who has a joint post with JPL and the Australian National University in Canberra.
LISA is a proposed joint NASA and European Space Agency mission. The NASA portion of the mission is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. Some of the key instrumentation studies for the mission are being performed at JPL. The U.S. mission scientist is Tom Prince at the California Institute of Technology in Pasadena. JPL is managed by Caltech for NASA.
For more information visit http://www.nasa.gov/topics/universe/features/lisa20101123.html
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