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Scientists turning to crowdsourcing to gather more information about earthquakes - 1 views

  • In the past, seismologists have had to rely on information provided by just a few sensors in the vicinity of an earthquake to get information about it
  • afterwards, on anecdotal evidence provided by people that had experienced the quake first hand
  • new sources of data are becoming available that are giving scientists much more information about an earthquake,
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  • example is Twitter. Because it’s a public system, scientists can use filters to pinpoint messages being sent about a specific topic, in this case earthquakes
  • researchers can watch in real time as people send messages about it, outpacing the quake itself
  • new sources of data are becoming available as well as more people become interested in helping scientists gather data
  • Seismic monitors can now be purchased by ordinary citizens, for example, and attached to buildings, private or public where they send data via WiFi to designated research facilities
  • Other new sources of data are becoming available as well as more people become interested in helping scientists gather
  • Smartphone apps are now available as well that can be used to turn a phone into a vibration sensing device during times when the phone is not being carried.
  • earthquake scientists have also begun to set up websites with query forms that people can fill in to add what they know about an earthquake to an existing database
  • seismologists are able to create a far more detailed picture of an earthquake
  • helps in understanding what led to it occurring and the more detailed information scientists receive the more accurate their prediction models should become
  • Citizens have long participated in earthquake science through the reporting, collection, and analysis of individual experiences
  • Today's communications infrastructure has taken citizen engagement to a new level
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Could Pulses in Earth's Magnetic Field Forecast Earthquakes? | Science/AAAS | News - 0 views

  • In the days leading up to some recent moderate-sized earthquakes, instruments nearby have picked up brief low-frequency pulses in Earth’s magnetic field
  • A few scientists have proposed that such pulses, which seemed to become stronger and more frequent just before the earthquakes occurred, could serve as an early warning sign for impending seismic activity
  • Now, a team has come up with a model for how these magnetic pulses might be generated, though some critics say they may have a humanmade origin.
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  • Brief fluctuations in Earth’s magnetic field have been detected before many earthquakes in the past 50 years
  • Friedemann Freund, a crystallographer at San Jose State University
  • in the weeks before a magnitude-5.4 quake struck about 15 kilometers northeast of San Jose in October 2007, an instrument near the epicenter sensed a number of unusual magnetic pulses
  • Those blips became more frequent as the day of the earthquake approached, Freund says
  • recently, prior to several medium- to moderate-sized quakes in Peru, two sensitive magnetometers recorded the same sort of pulses
  • how such pulses could be generated
  • suggest that these blips stem from microscopic changes in crystals in rocks under seismic stress deep within Earth
  • In many types of rocks, particularly volcanic rocks that have substantial amounts of water locked inside them, crystals are chock-full of oxygen-oxygen bonds called peroxy bonds
  • (These bonds formed long ago, after chemical changes split some of the water molecules, freeing the hydrogen atoms to bond together and then diffuse out of the rocks as gas.)
  • When those rocks are squeezed, say, by the sides of a fault zone scraping past one another, some of the peroxy bonds break
  • Those broken bonds release negatively charged electrons, which remain trapped in place, and create positively charged “holes” in the crystal
  • his team propose that the same process might be happening within Earth’s crust
  • As stress on large volumes of rock builds in advance of an impending quake, many, many of these electrical holes are created inside them
  • the mass migration of such holes that creates the large electrical currents responsible for generating the low-frequency magnetic pulses that make their way to detectors on Earth’s surface
  • they say
  • some critics of his model have proposed
  • lightning
  • as an alternative explanation
  • he notes, with data from the two sensors in Peru he and his colleagues were able to pinpoint the strongest of those pulses as originating within a few kilometers of the epicenters of subsequent quakes
  • For now, Freund admits, the team’s model is preliminary: The paper has been submitted to a journal and is now being reviewed by other scientists.
  • two instruments aren’t sufficient to pinpoint the location of an event; to truly “triangulate” an event you need at least three sensors
  • “I’m concerned that the pulses are not originating deep within the Earth.”
  • “This paper only makes sense if the observations [of magnetic pulses] are good,”
  • John Ebel, a seismologist at Boston College, who wasn’t involved in the research
  • the blips may have some inexplicable humanmade origin
  • Decades ago
  • his Boston-based magnetometers started picking up a series of odd pulses every morning.
  • Eventually
  • identified
  • It was the engineers cranking up Boston’s trolley cars at a rail yard a few kilometers away from the instruments
  • Even if the magnetic pulses originate within Earth along seismic zones under stress, Freund says, the blips don’t always foretell a quake
  • It’s more likely to be the pattern of pulses—and, in particular, changes in their size and frequency—that Freund and his colleagues say might offer scientists a crystal ball for impending temblors
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March 27 - Today in Science History - Scientists born on March 27th, died, and events - 0 views

  • Alaska earthquake
  • In 1965, south central Alaska was rocked by North America's greatest earthquake. (At 8.3-8.5 on the Richter scale, it released over twice the energy of the 1906 San Francisco earthquake.) Its epicenter was near Price William Sound, along a 1,000 km thrust fault where the Pacific plate subducts under the North american plate. The earthquake tilted at least 120,000 sq km. Some landmasses were thrust up locally as high as 25 m; elsewhere land sank as much as 2.5m. The shock was felt over almost 1,300,000 sq km. Extensive coastal damage resulted from submarine landslides and tsunamis which caused 122 of the 131 deaths. Property damage cost was about $311 million. Tsunami damage reached Crescent City, Calif. Tens of thousands of aftershocks indicated that the region of faulting extended about 1,000 km.
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Scientists Identify Cause of Japan's Devastating 2011 Tsunami - 0 views

  • In March 2011, a devastating tsunami struck Japan's Tohoku region
  • Now, researchers have uncovered the cause of this tsunami, shedding light on what displaced the seafloor off the northeastern coast of Japan
  • Learning more about the 2011 tsunami and its causes is an important step for monitoring future events.
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  • could help researchers provide earlier warnings
  • During their study
  • scientists underwent a 50-day expedition on the Japanese drilling vessel Chikyu
  • They then drilled three holes in the Japan Trench area in order to study the rupture zone of the 2011 earthquake
  • a fault in the ocean floor where two of Earth's major tectonic plates meet deep beneath the surface of the Pacific Ocean.
  • The conventional view among geologists
  • has been that deep beneath the seafloor, where rocks are strong, movements of the plates can generate a lot of elastic rebound
  • Closer to the surface of the seafloor, where rocks are softer and less compressed, this rebound effect was thought to taper off
  • In fact
  • the largest displacement of plates before the 2011 tsunami occurred in 1960 off the coast of Chile
  • That's when a powerful earthquake displaced seafloor plates by an average of 20 meters
  • The Tohoku earthquake, in contrast, displaced its own plates by 30 to 50 meters.
  • So what caused this unexpectedly violent slip
  • the fault itself is very thin--less than five meters thick in the area sampled.
  • makes it the thinnest plate boundary on Earth.
  • In addition, clay deposits that fill the narrow fault are made of extremely fine sediment, which makes it extremely slippery
  • these findings don't just show researchers a bit more about the past; they also have implications for the future
  • Other subduction zones in the northwest Pacific where this type of clay is present--from Russia's Kamchatka peninsula to the Aleutian Islands--may also be capable of generating similar, huge earthquakes
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Unusual Indian Ocean Earthquakes Hit at Tectonic Breakup: Scientific American - 0 views

  • According to prevailing theories of plate tectonics, the Indo-Australian plate began to deform internally about 10 million years ago
  • thrusting the Himalayas up and slowing India down
  • Most scientists think that the Australian portion forged ahead, creating twisting tensions
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  • inferred the presence of these seismic stresses by modeling stress changes from shortly before the 2012 earthquakes
  • magnitude-9.1 tremor in 2004
  • and another quake in 2005 — probably triggered the 2012 event by adding to pent-up stresses in the plate’s middle region.
Mars Base

January 26 - Today in Science History - Scientists born on January 26th, died, and events - 0 views

  • Canadian earthquake   In 1700, an earthquake, the most intense Canada has ever seen, hit the sea floor off the British Columbia coast. Long before Europeans first landed on Vancouver Island, native legend tells of a great disaster. The sea rose in a heaving wave, and landslides buried a sleeping village. Myth was resolved with science in 2003 by government research. Earthquakes of that intensity cause tidal waves, and Japanese written history tells of a massive tsunami striking fishing villages the next day along the coast of Honshu, killing hundreds. Coupled with geological evidence of the level 9 quake, the connection was clear. Mythology and seismology came together to validate history.
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Sumatra quake was part of crustal plate breakup: Study shows huge jolt measured 8.7, ri... - 0 views

  • Seismologists have known for years that the Indo-Australian plate of Earth's crust is slowly breaking apart
  • quake was caused by at least four undersea fault ruptures
  • within a 2-minute, 40-second period
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  • This is part of the messy business of breaking up a plate. … This is a geologic process
  • will take millions of years to form a new plate boundary
  • likely, it will take thousands of similar large quakes for that to happen."
  • All four faults
  • were strike-slip faults, meaning ground on one side of the fault moves horizontally past ground on the other side
  • great quake of last April 11 "is possibly the largest strike-slip earthquake ever seismically recorded
  • although a similar size quake in Tibet in 1950 was of an unknown type
  • 2012 quakes likely were triggered, at least in part, by changes in crustal stresses caused by the magnitude-9.1 Sumatra-Andaman earthquake of Dec. 26, 2004
  • the 8.7 and 8.2 quakes were generated by horizontal movements
  • not by vertical motion
  • explains why they didn't generate major tsunamis
  • 8.7 quake caused small tsunamis, the largest of which measured about 12 inches in height at Meulaboh, Indonesia
  • Indo-Australian plate is breaking into two or perhaps three pieces
  • happening because it is colliding with Asia in the northwest, which slows down the western part of the plate, while the eastern part of the plate continues moving more easily by diving or "subducting" under the island of Sumatra to the northeast
  • subduction zone off Sumatra caused the catastrophic 2004 magnitude-9.1 quake and tsunami
  • ruptured along a roughly 90-mile length
  • seafloor on one side of the fault slipped about 100 feet past the seafloor on the fault's other side
  • second fault, which slipped about 25 feet, began to rupture 40 seconds after
  • extended an estimated 60 miles to 120 miles north-northeast to south-southwest – perpendicular to the first fault and crossing it.
  • third fault was parallel to the first fault and about 90 to the miles southwest
  • started breaking 70 seconds after the quake began
  • along a length of about 90 miles
  • slipped about 70 feet
  • The fourth fault paralleled the first and third faults
  • began to rupture 145 seconds after the quake began
  • fault rupture was roughly 30 miles to 60 miles long.
  • fault slipped about 20 feet past ground on the other side
Mars Base

Santorini Bulges as Magma Balloons Underneath - 0 views

  • Santorini locals began to suspect last year that something was afoot with the volcano under their Greek island group
  • Wine glasses occasionally vibrated and clinked in cafes, suggesting tiny tremors, and tour guides smelled strange gasses.
  • satellite radar technology has revealed the source of the symptoms. A rush of molten rock swelled the magma chamber under the volcano by some 13 to 26 million cubic yards (10 to 20 million cubic meters)—about 15 times the volume of London's Olympic Stadium—between January 2011 and April 2012
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  • even forced parts of the island's surface to rise upward and outward by 3 to 5.5 inches (8 to 14 centimeters).
  • volcano has been quiet for 60 years
  • recent events don't indicate an imminent eruption
  • the earthquake activity and the rate of bulging have both slowed right down in the last few months, it doesn't look as though the volcano is about to start to erupt, and it is quite likely that it could remain quiet for another few years or decades.
  • don't know enough about the lifecycle of large volcanoes in between eruptions to be certain
  • beginning in the January 2011 data, more than a thousand small quakes, most of them imperceptible
  • confirmed a subtle rise in Santorini's surface level with satellite radar images and GPS receivers
  • Catastrophic eruptions on Santorini, which produce mostly pumice rather than lava, appear to occur here about 20,000 years apart
  • The last one, in 1950, oozed enough lava to cover a few tennis courts
  • Despite its relative quiet, Santorini is an ideal location to learn more about processes like the magma chamber's rapid inflation
  • While satellite evidence of swelling magma chambers has rarely been available for an active volcano, the processes the data represent may not be all that unusual
  • some large volcanoes like Santorini and Yellowstone spend hundreds or thousands of years in a state of what you'd call dormancy
  • they'll often have these little restless patches
  • These types of phenomena are likely to be common, but you need the right instruments and technology to detect what are usually rather small changes in behavior."
  • we aren't any closer to knowing if, or when, the next lava eruption might happen
  • likening the recent swelling to someone blowing a big breath into an invisible balloon.
  • don't know how small or big the balloon is, and we don't know whether just one more breath will be enough for it to pop or not
Mars Base

Magma Boils Beneath Antarctic Ice | Science/AAAS | News - 0 views

  • Marie Byrd Land is a desolate region of Antarctica buried deep beneath the West Antarctic Ice Sheet
  • Historic eruptions have punctured the ice sheet, creating a chain of volcanoes amid the ice
  • researchers have shown that molten rock still stirs deep underground
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  • Only the largest eruptions could melt all the ice above them and poke through to the surface, but even smaller eruptions could potentially cause global sea level to rise, although no one knows how big the rise might be
  • The crust is thinned by the West Antarctic Rift System, a series of giant rift valleys beneath the ice sheet
  • erupted lava from underground magma chambers has burst through the ice repeatedly over geological history as the plates moved over the top
  • No one knew whether magma was still stirring
  • until seismic monitoring stations were installed on the ice between 2007 and 2010.
  • Researchers built the stations to study the shifting crustal blocks of the West Antarctic Rift System
  • But seismologist
  • found another use
  • They noticed a series of small earthquakes, mainly occurring during two “seismic swarms” in January and February 2010 and March 2011
  • These earthquakes were unusual: The ground was shaking much more slowly during the quakes than one would expect from the plates grinding against each other
  • looked at two different types of waves that come in—the P wave, which is the primary wave, and the S wave, which is the secondary wave
  • calculations revealed that the waves had come from 25 to 40 kilometers below Earth's surface and were centered around a point
  • approximately the point the volcanic activity should have reached if it had continued the linear trend of volcanoes to the south
  • The exact cause of these deep quakes is not understood, but they are thought to result from the movement of magma deep below active or soon-to-be active volcanoes
  • They found that the area showed a slightly higher magnetic field than the surrounding area and that there was a bump in the crust—common signals of magmatic activity
  • Radar mapping also indicated a layer of volcanic ash embedded in the ice
  • probably
  • from an eruption of Mount Waesche about 8000 years ago—very recent geological history
  • There is no evidence of an actual eruption since then, but, because magma is still moving deep under the Earth, an eruption could occur at any time
  • The current center of volcanic activity is covered by at least 1 kilometer of ice, and it would take an exceptionally large eruption to melt all this
  • But an eruption could make its presence felt in subtler ways. As fresh snow adds to their own mass, ice sheets flow downward into the sea
  • melting the base of the ice sheet, an eruption could speed up this flow, potentially raising the level of the ocean. No one knows how significant such a rise might be
  • Any effect on the ice sheet above, and thus any effect on the oceans, would probably be quite small
  • a proper study is needed to find out how significant volcanic activity could be to future sea levels
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Dazzling Meteor Fireball Lights Up UK Night Sky | Space.com - 0 views

  • A spectacular meteor wowed stargazers across the United Kingdom Friday (Sept. 21) when it flared up and shattered into piece
  • spotted by observers across Scotland and northern England as well as Ireland
  • Many observers captured views of the meteor on camera
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  • video of the Sept. 21 meteor shows what appears to be a fireball created as a small space rock breaks apart in Earth's atmosphere. Pieces of the meteor can easily be seen separating from the main body in his view
  • many witnesses to wonder if it was sparked by a man-made piece of space junk falling out of orbit
  • experts have conclusively tied the event to a naturally occurring space rock burning up in Earth's atmosphere
  • Veteran satellite tracker Marco Langbroe
  • the fireball was definitely a meteor.
  • sighting reports to determine the fireball's trajectory and studied videos posted by witnesses to determine how long it lasted
  • ack-of-the-envelope reconstruction therefore shows that this must have been a meteoric fireball, quite likely of asteroidal origin, and we definitely can exclude a satellite re-entry
  • meteor in space is called a meteoroid. Only when it flares up in the night sky does it become a meteor. Any remains of the object that reach the ground, meanwhile, are called meteorites
  • Earlier this year, a rare daytime fireball surprised U.S. observers in California and Nevada when it unleashed a sonic boom that some mistook for a small earthquake. The meteor was caused by a minivan-size asteroid and created several meteorites that NASA retrieved in a follow-up search
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Russia meteor virtually impossible to see coming | Atom & Cosmos | Science News - 0 views

  • Scientists have begun piecing together the characteristics of the meteor that exploded over Russia on the morning of February 15, using data from seismic instruments that track earthquakes and microphones designed to detect sonic booms from nuclear explosions
  • The explosion had the equivalent of up to 500,000 tons of TNT
  • about 30 times the energy output of the Hiroshima atomic bomb
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  • only 5 percent of the energy of the famous 1908 Tunguska meteor that downed trees over a 2,000-square-kilometer area in Siberia
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Smallest Exoplanet Yet Discovered by 'Listening' to a Sun-like Star - 0 views

  • Scientists have discovered a new planet orbiting a Sun-like star, and the exoplanet is the smallest yet found in data from the Kepler mission
  • Kepler-37b, is smaller than Mercury, but slightly larger than Earth’s Moon
  • discovery came from a collaboration between Kepler scientists and a consortium of international researchers who employ asteroseismology
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  • measuring oscillations in the star’s brightness caused by continuous star-quakes, and turning those tiny variations in the star’s light into sounds
  • The bigger the star, the lower the frequency, or ‘pitch’ of its song
  • The measurements made by the astroseismologists allowed the Kepler research team to more accurately measure the tiny Kepler-37b
  • revealing two other planets in the same planetary system: one slightly smaller than Earth and one twice as large
  • Kepler-37b is very likely a rocky planet with no atmosphere or water, similar to Mercury
  • “The detection of such a small planet shows for the first time that stellar systems host planets much smaller as well as much larger than anything we see in our own Solar System.”
  • host star, Kepler-37, is about 210 light-years from Earth
  • All three planets orbit the star at less than the distance Mercury is to the Sun
  • Kepler-37b orbits every 13 days at less than one-third Mercury’s distance from the Sun
  • estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin
  • hot enough to melt the zinc in a penny
  • Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively
  • The size of the star must be known in order to measure the planet’s size accurately
  • scientists examined sound waves generated by the boiling motion beneath the surface of the star
  • The technique for stellar seismology is analogous to how geologists use seismic waves generated by earthquakes to probe the interior structure of Earth
  • sound waves travel into the star and bring information back up to the surface
  • waves cause oscillations that Kepler observes as a rapid flickering of the star’s brightness
  • barely discernible, high-frequency oscillations in the brightness of small stars are the most difficult to measure
  • why most objects previously subjected to asteroseismic analysis are larger than the Sun
  • Kepler-37 has a radius just three-quarters of the Sun
  • the radius of the star is known to 3 percent accuracy, which translates to exceptional accuracy in the planet’s size.
  • this discovery took a long time to verify, as the signature of this very small exoplanet was hard to confirm
  • Kepler is sending astronomers photometry data that’s “probably the best we’ll see in our lifetimes
  • uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible
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Twitter Kept Up With Haiti Cholera Outbreak - Science News - 0 views

  • Twitter, blogs and other social media can be powerful tools for tracking infectious diseases as they spread
  • researchers who followed social media during Haiti’s post-earthquake cholera outbreak in 2010.
  • Twitter posts and news about cholera gathered
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  • in the first 100 days of the outbreak tracked closely
  • data reported from hospital and clinics
  • social media data were available almost instantly
  • others have shown that Twitter and other online sources can provide meaningful information about outbreaks of diseases such as H1N1 and swine flu
  • new work establishes that the approach is useful for tracking a disease that emerges in the unsafe living conditions that often follow a disaster, says Polgreen.
  • 188,819 tweets that contained or were tagged with the word cholera during the first 100 days of the cholera outbreak
  • analysis suggests the social tool provides a good measure of the disease’s spread
  • The researchers compared the tweets to data from HealthMap, a disease-tracking tool that mines Internet news stories, blogs and discussion groups and lets the public report illness by cell phone. Both the Twitter and HealthMap data corresponded to official data from the Haitian Ministry of Public Health.
  • Official sources of data are better validated, but on the downside they are going to take time
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May 18 - Today in Science History - Scientists born on May 18th, died, and events - 0 views

  • Mount St. Helens
  • In 1980, following a weeklong series of earthquakes and smaller explosions of ash and smoke, the long-dormant Mount St. Helens volcano erupted in Washington state, U.S., hurling ash 15,000 feet into the air and setting off mudslides and avalanches. The eruptions caused minimal damage in the sparsely populated area, but about 400 people - mostly loggers and forest rangers - were evacuated. The explosion was characterized as the equivalent of 27,000 atomic bombs. The cloud of ash eventually circled the globe
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35-year-old ISEE 3 Craft Phones Home | Sky & Telescope - 0 views

  • The team successfully established contact that afternoon — notwithstanding a minor earthquake in the area — at a heart-thumping transmission rate of 512 bits per second.
  • approval from NASA to attempt contact, and that go-ahead came on May 29th
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ISEE-3 Reboot Project Update: BULLSEYE! and More - Space College - 0 views

  • spacecraft has two transponders,
  • transponder A and Transponder B
  • Transponder B is normally the engineering telemetry transponder and transponder A is the ranging transponder
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  • The final state of the spacecraft before was to have both of the transponders transmitters active and that is what people around the world have been tracking.
  • the spacecraft is set up with a lot of redundancy so you can use either transponder A or B to send telemetry or range
  • We tried several times to command the spacecraft's B transponder at 2041.9479 MHz into the mode where it normally sends engineering telemetry
  • did not work
  • Then we tried the same process on transponder A
  • modulation from the output of the telemetry system
  • The initial command was just to turn engineering telemetry on at 512 bits/second. This was successful.
  • successfully commanded the spacecraft into engineering telemetry mode.
  • initial verification
  • later
  • through the A transponder's receiver we commanded through the B transponder's command decoder to output engineering telemetry through transponder B's transmitter
  • verified so far the following systems on the spacecraft
  • 1. Transponder A receiver
  • 2. Transponder A's Command Decoder and Data Handling Unit
  • 3. Transponder B's Command Decoder and Data Handling Unit
  • tried to command the spacecraft into 64 bits/second mode, which was a mode that is much more complicated to set up and we did not get working successfully during the limited time that the spacecraft is visible from Arecibo
  • need to do this so that the smaller dishes at Morehead State and Bochum will have a positive signal margin so that we can record several hours of data
  • neither of the ISEE-3/ICE receivers had met their specification in testing
  • for -120 dbm sensitivity
  • receiver A was tested at about -114 dbm, and Receiver B at -111 dbm
  • after our end to end systems test we had an earthquake
  • how observations could be affected by vibrations in the dome structure as it translates during an observation and then that happened
  • later processed our first day's data dump from the spacecraft and we received 49 full frames of data at a bit rate of 512 bits/second
  • there were no errors on the downlink
  • milestones related to commanding and receiving data
  • 1. Successful commanding multiple times of ISEE-3/ICE
  • 2. Received engineering telemetry from both data multiplexing units on the spacecraft
  • 3. Successful demodulation on the ground of the received data, through the output of bits
  • 4. Verification of good data at 512 bits/sec, including frame synchronization, correct number of bits/frame, and with no errors, showing a very strong 30+ db link margin through Arecibo
  • If we can maneuver the spacecraft by June 17th we get the very small delta V number
  • this starts to climb rapidly as the spacecraft gets closer to the moon
  • cannot at this time rule out a lunar impact.
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