Showing posts with label cassini spacecraft. Show all posts
Showing posts with label cassini spacecraft. Show all posts

NASA Goddard Delivers Magnetometers for NASA's Next Mission to Mars

Mission to Mars

Magnetometers built by scientists and engineers at NASA Goddard Space Flight Center in Greenbelt, Md. for NASA's Mars Atmosphere And Volatile EvolutioN (MAVEN) mission have been delivered to the University of California at Berkeley Space Sciences Laboratory for integration into the Particles and Field Package.

"The team worked hard and completed delivery of the magnetometers on schedule," said Jack Connerney, Magnetometer Instrument Lead from NASA Goddard. "We are looking forward to launch, orbit insertion and seeing the data come back."

The pair of flux gate magnetometers measures the magnetic field at the location of the spacecraft. As part of the Particles and Fields Package, the magnetometer sensors are positioned at the outermost ends of the solar panels to keep them as far away as possible from stray magnetic fields generated by the spacecraft. Since the motion of escaping charged particles is governed by the magnetic field, this measurement is important in understanding how the solar wind interacts with the planet’s atmosphere and causes loss to space.

NASA's Lunar Reconnaissance Orbiter Brings 'Earthrise' to Everyone

NASA's Lunar

The spacecraft rolls over, and you glimpse a sliver of intense light starting to climb over the rough horizon. It might be dawn, except that the bright sliver quickly morphs into an arc of dazzling white swirled with vivid blue and then rises far enough to be recognized as the brilliant, marbled Earth. Captured on film, this breathtaking view becomes the iconic photograph "Earthrise."

On December 24, 1968, three people saw this happen firsthand: Apollo 8 Commander Frank Borman and crew members William A. Anders and James A. Lovell, Jr. Now, in honor of Earth Day 2012, the rest of us can see what that was like in a new NASA visualization, which draws on richly detailed maps of the moon's surface made from data gathered by NASA's Lunar Reconnaissance Orbiter (LRO).

"This visualization recreates for everyone the wondrous experience of seeing Earth from that privileged viewpoint," says LRO Project Scientist Rich Vondrak of NASA's Goddard Space Flight Center in Greenbelt, Md. At the time of the famous photo, Apollo 8 was rounding the moon for the fourth time, traveling in a nearly circular orbit about 110 kilometers (68 miles) above the moon's surface at about a mile per second. "The spacecraft was pointed down to look at the moon's surface, because Anders was conducting an extensive photographic survey," explains James Rice, an astrogeologist at Goddard. "But Lovell needed to perform a navigation sighting, so Borman rolled the spacecraft." That's when Earth abruptly appeared.

Useful Links: Merchants Moving, Southern, Anywhere

Launch Aborts Challenge Rocket Engineers

Launch Rocket

While companies design and perfect spacecraft and rockets to take people into space safely, teams of NASA engineers are deciphering what needs to happen if a launch goes wrong. In other words, what kind of ejection system will astronauts need to survive?

"We're trying to give the crew that last option for when things go bad," said Brent Jett, deputy director of NASA's Commercial Crew Program, or CCP, and four-time space shuttle astronaut. Keep in mind that the system needs to work at all points during ascent, from the launch pad where the air is thick and the spacecraft is not moving at all, to more than 100 miles above Earth, where there is no discernable air and the spacecraft and crew are speeding along at 17,500 mph, or about 5 miles a second.

Also, consider that because rockets can malfunction and even explode within a second of the first problem, the ejection system needs to be able to spot a problem and get the spacecraft out of danger before it's too late. "Basically, you're separating from the rocket with a smaller rocket and it's a pretty extreme environment to put the crew into," said Chris Gerace, deputy chief of CCP's Systems Engineering and Requirements Office.


MSL "Go" for Nov. 25 Launch

MSL

NASA and contractor managers for the Mars Science Laboratory (MSL) launch held their Flight Readiness Review meeting at NASA's Kennedy Space Center this morning. After an evaluation of the MSL spacecraft and United Launch Alliance Atlas V rocket, managers gave a "go" to continue proceeding toward a liftoff at 10:25 a.m. EST next Friday, Nov. 25. Managers will meet again Nov. 22 for the Launch Readiness Review.

The spacecraft -- with its rover, Curiosity -- is sealed inside the protective payload fairing atop the Atlas V rocket, which stands inside the Vertical Integration Facility at nearby Cape Canaveral Air Force Station's Launch Complex 41. Closeouts of the spacecraft and the Atlas V fairing are planned for Saturday, with a countdown dress rehearsal on Sunday's schedule.

Curiosity has 10 science instruments to search for evidence about whether Mars has had environments favorable for microbial life, including the chemical ingredients for life. The unique rover will use a laser to look inside rocks and release the gasses so that its spectrometer can analyze and send the data back to Earth.


New Crew Launches to Join Expedition 29

New Crew Launches

Expedition 29 crew members Anton Shkaplerov, Anatoly Ivanishin and Dan Burbank are on their way to the International Space Station. The Soyuz TMA-22 spacecraft carrying the new trio launched from Baikonur Cosmodrome, Kazakhstan, at 11:14 p.m. EST Sunday (10:14 a.m. Baikonur time Monday).

The Soyuz TMA-22 will dock to the Poisk mini-research module at 12:33 a.m. Wednesday. Expedition 29 Commander Mike Fossum and Flight Engineers Satoshi Furukawa and Sergei Volkov will welcome their new crewmates a little while later when they open the hatches about 2:55 a.m. Shkaplerov, Ivanishin and Burbank are scheduled to live and work aboard the orbiting laboratory until March.

NASA astronaut and Flight Engineer Dan Burbank is making his third visit to the International Space Station. His previous two visits were both aboard space shuttle Atlantis. He helped prepare the station for its first crew during STS-106 and helped install the P3/P4 truss during STS-115.


NASA Studying Ways to Make 'Tractor Beams' a Reality

Tractor Beams

Tractor beams the ability to trap and move objects using laser light -- are the stuff of science fiction, but a team of NASA scientists has won funding to study the concept for remotely capturing planetary or atmospheric particles and delivering them to a robotic rover or orbiting spacecraft for analysis.

The NASA Office of the Chief Technologist (OCT) has awarded Principal Investigator Paul Stysley and team members Demetrios Poulios and Barry Coyle at NASA's Goddard Space Flight Center in Greenbelt, Md., $100,000 to study three experimental methods for corralling particles and transporting them via laser light to an instrument -- akin to a vacuum using suction to collect and transport dirt to a canister or bag. Once delivered, an instrument would then characterize their composition.

"Though a mainstay in science fiction, and Star Trek in particular, laser-based trapping isn't fanciful or beyond current technological know-how," Stysley said. The team has identified three different approaches for transporting particles, as well as single molecules, viruses, ribonucleic acid, and fully functioning cells, using the power of light.

Cassini Closes in on Saturn's Tumbling Moon Hyperion

Cassini Closes

NASA's Cassini spacecraft captured new views of Saturn's oddly shaped moon Hyperion during its encounter with this cratered body on Thursday, Aug. 25. Raw images were acquired as the spacecraft flew past the moon at a distance of about 15,500 miles (25,000 kilometers), making this the second closest encounter.

Hyperion is a small moon -- just 168 miles (270 kilometers) across. It has an irregular shape and surface appearance, and it rotates chaotically as it tumbles along in orbit. This odd rotation prevented scientists from predicting exactly what terrain the spacecraft's cameras would image during this flyby.

However, this flyby's closeness has likely allowed Cassini's cameras to map new territory. At the very least, it will help scientists improve color measurements of the moon. It will also help them determine how the moon's brightness changes as lighting and viewing conditions change, which can provide insight into the texture of the surface. The color measurements provide additional information about different materials on the moon's deeply pitted surface.

Cassini Probe Sees Electric Link With Saturn And One Of Its Moons

http://nasa-satellites.blogspot.com/
NASA is releasing the first images and sounds of an electrical connection between Saturn and one of its moons. The data collected by the agency's Cassini spacecraft enable scientists to improve their understanding of the complex web of interaction between the planet and its numerous moons. The results of the data analysis are published in the journals Nature and Geophysical Research Letters. Scientists previously theorized an electrical circuit should exist at Saturn. After analyzing data that Cassini collected in 2008, scientists saw a glowing patch of ultraviolet light emissions near Saturn's north pole that marked the presence of a circuit, even though the moon is 150,000 miles (240,000 kilometers) away from the planet.

The patch occurs at the end of a magnetic field line connecting Saturn and its moon Enceladus. The area, known as an auroral footprint, is the spot where energetic electrons dive into the planet's atmosphere, following magnetic field lines that arc between the planet's north and south polar regions. "The footprint discovery at Saturn is one of the most important fields and particle revelations from Cassini and ultimately may help us understand Saturn's strange magnetic field," said Marcia Burton, a Cassini fields and particles scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It gives us the first visual connection between Saturn and one of its moons."

The auroral footprint measures approximately 750 miles by less than 250 miles, covering an area comparable to California or Sweden. At its brightest, the footprint shone with an ultraviolet light intensity far less than Saturn's polar auroral rings, but comparable to the faintest aurora visible at Earth without a telescope in the visible light spectrum. Scientists have not found a matching footprint at the southern end of the magnetic field line. "Cassini fields and particles instruments found particle beams aligned with Saturn's magnetic field near Enceladus, and scientists started asking if we could see an expected ultraviolet spot at the end of the magnetic field line on Saturn," said Wayne Pryor, a lead author of the Nature study released today, and Cassini co-investigator at Central Arizona College in Coolidge, Ariz. "We were delighted to find the glow close to the 'bulls-eye' at the center of our target."

Cassini Finds Enceladus is a Powerhouse

http://nasa-satellites.blogspot.com/
Heat output from the south polar region of Saturn's moon Enceladus is much greater than was previously thought possible, according to a new analysis of data collected by NASA's Cassini spacecraft. The study was published in the Journal of Geophysical Research on March 4. Data from Cassini's composite infrared spectrometer of Enceladus' south polar terrain, which is marked by linear fissures, indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fueled power stations. This is more than an order of magnitude higher than scientists had predicted, according to Carly Howett, the lead author of study, who is a postdoctoral researcher at Southwest Research Institute in Boulder, Colo., and a composite infrared spectrometer science team member.

"The mechanism capable of producing the much higher observed internal power remains a mystery and challenges the currently proposed models of long-term heat production," said Howett. It has been known since 2005 that Enceladus' south polar terrain is geologically active and the activity is centered on four roughly parallel linear trenches, 130 kilometers (80 miles) long and about 2 kilometers (1 mile) wide, informally known as the "tiger stripes." Cassini also found that these fissures eject great plumes of ice particles and water vapor continually into space. These trenches have elevated temperatures due to heat leaking out of Enceladus' interior.

A 2007 study predicted the internal heat of Enceladus, if principally generated by tidal forces arising from the orbital resonance between Enceladus and another moon, Dione, could be no greater than 1.1 gigawatts averaged over the long term. Heating from natural radioactivity inside Enceladus would add another 0.3 gigawatts. The latest analysis, which also involved the composite infrared spectrometer team members John Spencer at Southwest Research Institute, and John Pearl and Marcia Segura at NASA's Goddard Space Flight Center in Greenbelt, Md., uses observations taken in 2008, which cover the entire south polar terrain. They constrained Enceladus' surface temperatures to determine the region's surprisingly high output.

Cassini to Sample Magnetic Environment around Titan

http://nasa-satellites.blogspot.com/
NASA's Cassini spacecraft is set to skim close to Saturn's moon Titan on Friday, Feb. 18, to learn about the interaction between Titan and Saturn's magnetosphere, the magnetic bubble around the planet. The closest approach will take place at 8:04 a.m. PST (4:04 p.m. UTC) and bring Cassini within about 3,650 kilometers (2,270 miles) of Titan's surface. As Titan makes a complete 360-degree orbit around Saturn, the relative influence of the sun's illumination and the hot ionized gas trapped in the magnetic bubble changes. These factors are important for understanding the relationship between Titan and Saturn's magnetosphere. It is important to make measurements at a variety of locations in the Saturn magnetosphere, so this flyby will occur in a part of the magnetosphere that has been poorly sampled so far.

Previous flybys have shown the magnetic environment near Titan to be rather variable and unpredictable. For 12 hours before and after closest approach, the Cassini plasma spectrometer instrument will be pointing in a direction to capture ionized gas in the region. At the same time, Cassini's radio science subsystem will be gathering sensitive gravity data from Titan to improve understanding of the structure of the interior. Collecting data like these will eventually enable scientists to determine whether Titan has an ocean under its crust. Other instruments will also be collecting data, much of it pertaining to seasonal change.

Titan is currently in northern spring, approaching northern summer, and scientists want to know what has changed with the north polar winter vortex weather pattern. The composite infrared spectrometer, for instance, will be mapping temperatures in Titan's stratosphere. The imaging science subsystem will also be monitoring the lakes, clouds and transport of aerosols in the Titan atmosphere. This latest flyby is dubbed "T74," though planning changes early in the orbital tour have made this the 75th targeted flyby of Titan. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., 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. 

Cassini Spots Potential Ice Volcano On Saturn Moon

http://nasa-satellites.blogspot.com/
NASA's Cassini spacecraft has found possible ice volcanoes on Saturn's moon Titan that are similar in shape to those on Earth that spew molten rock. Topography and surface composition data have enabled scientists to make the best case yet in the outer solar system for an Earth-like volcano landform that erupts in ice. The results were presented today at the American Geophysical Union meeting in San Francisco. "When we look at our new 3-D map of Sotra Facula on Titan, we are struck by its resemblance to volcanoes like Mt. Etna in Italy, Laki in Iceland and even some small volcanic cones and flows near my hometown of Flagstaff," said Randolph Kirk, who led the 3-D mapping work, and is a Cassini radar team member and geophysicist at the U.S. Geological Survey (USGS) Astrogeology Science Center in Flagstaff, Ariz.

Scientists have been debating for years whether ice volcanoes, also called cryovolcanoes, exist on ice-rich moons, and if they do, what their characteristics are. The working definition assumes some kind of subterranean geological activity warms the cold environment enough to melt part of the satellite's interior and sends slushy ice or other materials through an opening in the surface. Volcanoes on Jupiter's moon Io and Earth spew silicate lava. Some cryovolcanoes bear little resemblance to terrestrial volcanoes, such as the tiger stripes at Saturn's moon Enceladus, where long fissures spray jets of water and icy particles that leave little trace on the surface.

At other sites, eruption of denser materials might build up volcanic peaks or finger-like flows. But when such flows were spotted on Titan in the past, theories explained them as non-volcanic processes, such as rivers depositing sediment. At Sotra, however, cryovolcanism is the best explanation for two peaks more than 3000 feet high with deep volcanic craters and finger-like flows. "This is the very best evidence, by far, for volcanic topography anywhere documented on an icy satellite," said Jeffrey Kargel, a planetary scientist at the University of Arizona, Tucson. "It's possible the mountains are tectonic in origin, but the interpretation of cryovolcano is a much simpler, more consistent explanation."

Cassini Back to Normal, Ready for Enceladus

http://nasa-satellites.blogspot.com/
NASA's Cassini spacecraft resumed normal operations today, Nov. 24. All science instruments have been turned back on, the spacecraft is properly configured and Cassini is in good health. Mission managers expect to get a full stream of data during next week's flyby of the Saturnian moon Enceladus. 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. 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. 

Cassini's CIRS Reveals Saturn Is on a Cosmic Dimmer Switch

http://nasa-satellites.blogspot.com/
Like a cosmic light bulb on a dimmer switch, Saturn emitted gradually less energy each year from 2005 to 2009, according to observations by NASA’s Cassini spacecraft. But unlike an ordinary bulb, Saturn's southern hemisphere consistently emitted more energy than its northern one. On top of that, energy levels changed with the seasons and differed from the last time a spacecraft visited in the early 1980s. These never-before-seen trends came from an analysis of comprehensive data from the Composite Infrared Spectrometer (CIRS), an instrument built by NASA's Goddard Space Flight Center in Greenbelt, Md., as well as a comparison with earlier data from NASA's Voyager spacecraft. When combined with information about the energy coming to Saturn from the sun, the results could help scientists understand the nature of Saturn's internal heat source.

The findings were reported November 9 in the Journal of Geophysical Research-Planets by Liming Li of Cornell University in Ithaca, N.Y., and colleagues from several institutions, including Goddard and NASA's Jet Propulsion Laboratory in Pasadena Calif., which manages the Cassini mission. "The Cassini CIRS data are very valuable because they give us a nearly complete picture of Saturn," says Li. "This is the only single data set that provides so much information about this planet, and it's the first time that anybody has been able to study the power emitted by one of the giant planets in such detail." The planets in our solar system lose energy in the form of heat radiation in wavelengths that are invisible to the human eye. The CIRS instrument picks up wavelengths in the thermal infrared region, which is beyond red light, where the wavelengths correspond to heat emission.

"In planetary science, we tend to think of planets as losing power evenly in all directions and at a steady rate," says Li. "Now we know Saturn is not doing that." Instead, Saturn's flow of outgoing energy was lopsided, with its southern hemisphere giving off about one-sixth more energy than the northern one, Li explains. This effect matched Saturn's seasons: during those five Earth years, it was summer in the southern hemisphere and winter in the northern one. Like Earth, Saturn has these seasons because the planet is tilted on its axis, so one hemisphere receives more energy from the sun and experiences summer while the other receives less energy and is shrouded in winter. Saturn’s equinox, when the sun was directly over the equator, occurred in August 2009.

The (Long) Weekend Warrior: Nine Moons, 62 Hours

http://nasa-satellites.blogspot.com/
Taking a long-weekend road trip, NASA's Cassini spacecraft successfully glided near nine Saturnian moons, sending back a stream of raw images as mementos of its adrenaline-fueled expedition. The spacecraft sent back particularly intriguing images of the moons Dione and Rhea. The Dione and Rhea pictures are the highest-resolution views yet of parts of their surfaces. The views of the southern part of Dione's leading hemisphere and the equatorial region of Rhea's leading hemisphere are more detailed than the last time we saw these terrains with NASA's Voyager spacecraft in the early 1980s.

Of the five big icy moons of Saturn, Dione and Rhea are often considered a pair because they orbit close to each other, are darker than the others, and exhibit similar patterns of light reflecting off them. These new images, however, highlight the differences between these sister moons. Both images show similar geographic regions on each satellite. However, scientists can identify differences in geological histories of the two bodies from differences in the numbers and sizes of visible craters on their surfaces. The number and size of craters on a body's surface help indicate the age of that surface the more craters there are and the larger they are, the older the surface is.

Rhea, for example, shows ancient, intense bombardments throughout this region. However, the same region of Dione is divided into distinct areas that exhibit variations in the number and size of preserved craters. In particular, while parts of Dione are heavily cratered like Rhea, there are other areas covered by relatively smooth plains. Those areas have many small craters, but few large impact scars, which indicates that they are geologically younger than the heavily cratered areas. The smooth plains must have been resurfaced at some point in Dione's past an event that seems to be missing from Rhea's geological history on this side of the moon.

Hello, Saturn Summer Solstice: Cassini's New Chapter

http://nasa-satellites.blogspot.com/
Turning a midsummer night's dream into reality, NASA's Cassini spacecraft begins its new mission extension the Cassini Solstice Mission today. The mission extension will take Cassini a few months past Saturn's northern summer solstice (or midsummer) through September 2017. It will enable scientists to study seasonal changes and other long-term weather changes on Saturn and its moons. Cassini had arrived just after Saturn's northern winter solstice in 2004, and the extension continues a few months past the northern summer solstice in May 2017. A complete seasonal period on Saturn has never been studied at this level of detail.

Cassini has revealed a bounty of scientific discoveries since its launch in 1997, including previously unknown characteristics of the Earth-like world of Saturn's moon Titan, and the plume of water vapor and organic particles spewing from another moon, Enceladus. The Cassini Solstice Mission will enable continued study of these intriguing worlds. It will also allow scientists to continue observations of Saturn's rings and the magnetic bubble around the planet, known as the magnetosphere. Near the end of the mission, the spacecraft will make repeated dives between Saturn and its rings to obtain in-depth knowledge of the gas giant. During these dives, the spacecraft will study the internal structure of Saturn, its magnetic fluctuations and ring mass.

Cassini entered orbit around Saturn in 2004. Mission managers had originally planned for a four-year tour of the Saturnian system. In 2008, Cassini received a mission extension through September 2010 to probe the planet and its moons through equinox, when the sun was directly over the equator. Equinox, which occurred in August 2009, marked the turn from southern fall to northern spring. The second mission extension, called the Cassini Solstice Mission, was announced earlier this year. "After nearly seven years in transit and six years in Saturn orbit, this spacecraft still just hums along," said Bob Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "With seven more years to go, the science should be just as exciting as what we've seen so far."