Investigation Tests New Methods of Water Recycling in Space

ISS - International Space Station logo.

July 25, 2017

Sometimes the best solution to a complex problem is the simplest one. That’s the approach that the Capillary Structures for Exploration Life Support (Capillary Structures) team took when designing the fluid physics investigation aboard the International Space Station. The Capillary Structures investigation uses capillary action, or the ability for a liquid to flow through a narrow spaces, such as small tubes, to move liquids and gases in microgravity, a task that can’t be tested in Earth’s gravity environment.

Life-support technology aboard any spacecraft is vitally important, especially as crews move farther away from Earth and into deep space. Many life support systems function differently in the space station’s microgravity environment than they would on Earth, including the way that liquids collect on and move across surfaces.

Image above: NASA astronaut Jack Fischer works with the capillary sorbent hardware, that is made up of 3D printed contactors (center) with several capillary channels. The contactors, or capillary structures under investigation, are supported by tubing, valves, and a pump. This highly interactive experiment simulates the fluidics of a liquid sorbent system for the removal of CO2 from the air. Image Credit: NASA.

Currently, the life-support systems aboard the space station require special equipment to separate liquids and gases. This technology utilizes rotating and moving parts that, if broken or otherwise compromised, could cause contamination and/or system failure. The Capillary Structures investigation studies a new method of water recycling and carbon dioxide removal using structures designed in specific shapes to manage fluid and gas mixtures in microgravity.

As opposed to the expensive, machine-based processes currently in use aboard the station, the Capillary Structures equipment is made up of small, 3-D printed geometric shapes of varying sizes that clip into place.

The impact of this research could benefit those on Earth as well. Research gathered during this investigation will teach us about using geometry to optimize evaporation, more efficient water recovery systems, passive purification methods, other water processing approaches on Earth. 

Image above: Prototype of the Capillary Evaporator hardware comprised of a test stand, lighting backdrop, and test arms to hold transparent capillary structures filled with test fluids. The structures are photographed over the course of several days while the fluids evaporate. Image Credit: IRPI LLC.

The first of this two-part investigation focuses on evaporation, a process that is specifically influenced by gravity and one that isn’t obvious in the microgravity environment of space.

“If you could do controllable evaporation in space, you could do all kinds of things” said Mark Weislogel, one of the project’s principal investigators.  “You could evaporate urine and recover all of the water. All of it. If you had a way of holding the liquid in a passive, no-moving-parts way like a puddle does on earth, but in space, then you could do a lot of unique processing, safely and with no maintenance.”

Crew members will fill each structure as research teams on the ground observe the behavior of the liquids over a few days via time lapse photography. Results from the investigation could lead to the development of new processes that are simple, trustworthy, and highly reliable in the case of an electrical failure or other mechanical system malfunction.

Image above: The Capillary Sorbent contactor designed with parallel, open channels to expose liquid to ambient air while containing and wicking fluids in a controlled manner. Image Credit: IRPI LLC.

“Were going to be getting detailed information about how the liquid evaporates out of the structures,” said Kyle Viestenz, co-investigator for the project. “The structures are set up to have different geometries, different angles, different heights, all these different parameters that we are varying across these structures to get quantitative data of evaporation in low gravity.”

The second part of the investigation demonstrates the use of fluids in a carbon dioxide removal system, called the Carbon Dioxide Liquid Sorbent System. This system uses a network of “water falls” to bring a liquid sorbent, or a material used to absorb gases, into contact with air, allowing the carbon dioxide to be carried away by the liquid. Of course, in a microgravity environment, the liquid does not “fall,” but is driven by surface tension forces generated passively by the unique surface geometry of the capillary structures.

International Space Station (ISS). Image Credit: NASA

Also comprised of 3-D printed capillary structures, this portion of the investigation is optimized for liquids to flow through the structures, rather than to simply evaporate.

“One of the things needed to scrub the carbon dioxide out of the air would be to split the fluid into multiple channels to achieve high surface area for the reaction,” said Viestenz. “In this investigation, we are going to be splitting the flow into multiple parallel open passages and recollecting them again--something that hasn’t been done before and will go a long way in demonstrating this kind of technology. The results are broadly applicable to liquid fuels, propellants, and coolants as well as myriad passive water management operations for life support”

For more information about other science happening aboard the orbiting laboratory, follow https://twitter.com/ISS_research. 

Related links:

Capillary Structures for Exploration Life Support (Capillary Structures): https://www.nasa.gov/mission_pages/station/research/experiments/2364.html

Fluid physics investigation: https://www.nasa.gov/connect/ebooks/researchers_guide_fluid_physics_detail.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Kristine Rainey/JSC/International Space Station Program Science Office/Jenny Howard.

Greetings, Orbiter.ch

Ring-Bow

NASA & ESA - Cassini-Huygens Mission to Saturn & Titan patch.

July 25, 2017

Although the rings lack the many colors of the rainbow, they arc across the sky of Saturn. From equatorial locations on the planet, they'd appear very thin since they would be seen edge-on. Closer to the poles, the rings would appear much wider;  in some locations (for parts of the Saturn's year), they would even block the sun for part of each day.

This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 10, 2017.

The view was obtained at a distance of approximately 680,000 miles (1.1 million kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 128 degrees. Image scale is 43 miles (69 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/Tony Greicius/JPL-Caltech/Space Science Institute.

Best regards, Orbiter.ch

Crew Tests Lower Body Suit to Protect Vision; Soyuz Rocket Rolls Out Wednesday

ISS - Expedition 52 Mission patch.

July 25, 2017

One of the effects of living in space is the tendency of fluids to shift upward towards an astronaut’s head. This results in the common “puffy face” appearance astronauts experience when they escape Earth’s gravity. However, the more serious effects observed on orbit could include eye and vision damage.

Image above: Astronaut Peggy Whitson looks at the Earth below from inside the seven-windowed cupola. Image Credit: NASA.

The three Expedition 52 crew members are exploring a unique device that reverses some of these headward fluid shifts and could counter changes to vision in space. Peggy Whitson of NASA tried on the Lower Body Negative Pressure suit today with assistance from Commander Fyodor Yurchikhin of Roscosmos. NASA astronaut Jack Fischer joined the commander and conducted brain/ear fluid pressure tests and eye exams on Whitson.

Image above: Watching the Aurora From Orbit. Expedition 52 Flight Engineer Jack Fischer of NASA shared photos and time-lapse video of a glowing green aurora seen from his vantage point 250 miles up, aboard the International Space Station. This aurora photo was taken on June 26, 2017. Image Credits: NASA/Jack Fischer.

Back on Earth, three new Expedition 52-53 crew members will see their Soyuz MS-05 rocket roll out to its launch pad Wednesday. The trio from the United States, Russia and Italy will blast off inside the Soyuz rocket Friday at 11:41 a.m. EDT from the Baikonur Cosmodrome in Kazakhstan. Randy Bresnik of NASA, Sergey Ryazanskiy from Roscosmos and Paolo Nespoli from the European Space Agency will live on the orbital complex until mid-December.

Related links:

Expedition 52: https://www.nasa.gov/mission_pages/station/expeditions/expedition52/index.html

Fluid shifts: https://www.nasa.gov/mission_pages/station/research/experiments/1257.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

Large, Distant Comets More Common Than Previously Thought

NASA - NEO WISE Mission logo.

July 25, 2017

Image above: This illustration shows how scientists used data from NASA's WISE spacecraft to determine the nucleus sizes of comets. They subtracted a model of how dust and gas behave in comets in order to obtain the core size. Image Credits: NASA/JPL-Caltech.

Comets that take more than 200 years to make one revolution around the Sun are notoriously difficult to study. Because they spend most of their time far from our area of the solar system, many "long-period comets" will never approach the Sun in a person's lifetime. In fact, those that travel inward from the Oort Cloud -- a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun -- can have periods of thousands or even millions of years.

NASA's WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about these distant wanderers. Scientists found that there are about seven times more long-period comets measuring at least 0.6 miles (1 kilometer) across than had been predicted previously. They also found that long-period comets are on average up to twice as large as "Jupiter family comets," whose orbits are shaped by Jupiter’s gravity and have periods of less than 20 years.

Researchers also observed that in eight months, three to five times as many long-period comets passed by the Sun than had been predicted. The findings are published in the Astronomical Journal.

"The number of comets speaks to the amount of material left over from the solar system's formation," said James Bauer, lead author of the study and now a research professor at the University of Maryland, College Park. "We now know that there are more relatively large chunks of ancient material coming from the Oort Cloud than we thought."

The Oort Cloud is too distant to be seen by current telescopes, but is thought to be a spherical distribution of small icy bodies at the outermost edge of the solar system. The density of comets within it is low, so the odds of comets colliding within it are rare. Long-period comets that WISE observed probably got kicked out of the Oort Cloud millions of years ago. The observations were carried out during the spacecraft's primary mission before it was renamed NEOWISE and reactivated to target near-Earth objects (NEOs).

"Our study is a rare look at objects perturbed out of the Oort Cloud," said Amy Mainzer, study co-author based at NASA's Jet Propulsion Laboratory, Pasadena, California, and principal investigator of the NEOWISE mission. "They are the most pristine examples of what the solar system was like when it formed."

An animation of a comet. Animation Credits: NASA/JPL-Caltech

Astronomers already had broader estimates of how many long-period and Jupiter family comets are in our solar system, but had no good way of measuring the sizes of long-period comets. That is because a comet has a "coma," a cloud of gas and dust that appears hazy in images and obscures the cometary nucleus. But by using the WISE data showing the infrared glow of this coma, scientists were able to "subtract" the coma from the overall comet and estimate the nucleus sizes of these comets. The data came from 2010 WISE observations of 95 Jupiter family comets and 56 long-period comets.

The results reinforce the idea that comets that pass by the Sun more often tend to be smaller than those spending much more time away from the Sun. That is because Jupiter family comets get more heat exposure, which causes volatile substances like water to sublimate and drag away other material from the comet’s surface as well.

"Our results mean there's an evolutionary difference between Jupiter family and long-period comets," Bauer said.

The existence of so many more long-period comets than predicted suggests that more of them have likely impacted planets, delivering icy materials from the outer reaches of the solar system.

Researchers also found clustering in the orbits of the long-period comets they studied, suggesting there could have been larger bodies that broke apart to form these groups.

The results will be important for assessing the likelihood of comets impacting our solar system's planets, including Earth.

"Comets travel much faster than asteroids, and some of them are very big," Mainzer said. "Studies like this will help us define what kind of hazard long-period comets may pose."

WISE spacecraft. Image Credits: NASA /JPL-Caltech

NASA's Jet Propulsion Laboratory in Pasadena, California, managed and operated WISE for NASA's Science Mission Directorate in Washington. The NEOWISE project is funded by the Near Earth Object Observation Program, now part of NASA’s Planetary Defense Coordination Office. The spacecraft was put into hibernation mode in 2011 after twice scanned the entire sky, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.

Related link:

Astronomical Journal: http://iopscience.iop.org/article/10.3847/1538-3881/aa72df

For more information on WISE, visit: https://www.nasa.gov/wise

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Elizabeth Landau.

Greetings, Orbiter.ch

Groundbreaking for an international neutrino experiment

CERN - European Organization for Nuclear Research logo.

24 Jul 2017

Image above: This 11-meter high prototype at CERN will refine neutrino detector technology. The final DUNE detectors will be 20 times larger than this prototype and located in the new LBNF cavern in the United States. (Image: M. Brice, J. Ordan/CERN).

Today, construction started on an international mega-science facility that will employ the expertise of CERN to study the properties of neutrinos; ghostly fundamental particles that play by an unknown set of rules. The 1.6km-deep experimental cavern is part of the Long Baseline Neutrino Facility, an international research centre located in the United States that will eventually host four giant neutrino detectors. Researchers at CERN are currently building prototypes for these detectors and experimenting with new technologies that will enhance our pictures of these ghostly cosmic nomads.

“Some of the open questions in fundamental physics today are related to extremely fascinating and elusive particles called neutrinos,” says CERN’s Director-General Fabiola Gianotti. “The Long-Baseline Neutrino Facility in the United States, whose start of construction is officially inaugurated with today’s ground-breaking ceremony, brings together the international particle physics community to explore some of the most interesting properties of neutrinos.’

Small Particles, Big Science: The International LBNF/DUNE Project

Video above: This animation explains how the Long-Baseline Neutrino Facility will operate and supply neutrino beams to the Deep Underground Neutrino Experiment (DUNE) 1300km from the source. (Video: Fermilab).

Neutrinos are among the most abundant fundamental particle in the universe, but little is known about them because they rarely interact with ordinary matter. Previous research has shown that neutrinos play by a different set of rules than all other particles, giving scientist hope that neutrinos might be the key to many lingering questions about the origin and evolution of the cosmos.

“Studying neutrinos could provide answers to some major mysteries in physics, such as why is the Universe made entirely of matter and not antimatter,” says Filippo Resnati, a CERN researcher working at the Neutrino Platform. “We need a powerful neutrino beam and huge detectors if we want to measure and understand their properties.”

Neutrinos can traverse thousands of kilometers through rock and dirt before bumping into a terrestrial atom. While this aloofness makes neutrinos incredibly difficult to detect, it is also the principle underlying the Deep Under Ground Neutrino Experiment, which will be the first tenant in the new LBNF cavern. As neutrinos travel, they change their properties—a phenomenon which is little understood. The LBNF/DUNE Experiment will catch and measure neutrinos generated by a proton beam at Fermilab near Chicago, Illinois, before and after their 1300km subterranean sprint to Sanford Lab located in Lead, South Dakota. CERN’s Neutrino Platform is hosting an international community of researchers as they design and build prototypes for DUNE’s far detectors.

“Building and testing large prototypes is a necessary intermediary step for a project as massive as LBNF/DUNE,” Marzio Nessi, the head of CERN’s Neutrino Platform saiys. “We’re figuring out how to adapt the existing technology to thrive inside a house-sized detector. Once we’ve proven that it can work, we will then scale it up by a factor of 25 for the final DUNE detectors.”

Image above: Workers stand on scaffolding inside the DUNE prototype (ProtoDUNE). The metallic paneling will act as an expandable tank for the liquid argon, which will generate electrons and light when a particle interacts with the atoms of the liquid. (Image: Maximilien Brice, Julien Ordan/CERN).

The CERN prototypes are refining a detection technology originally developed by Carlo Rubbia, a Nobel prize winning physicist and former CERN Director General. Hatched panels of delicate wires and photon sensors record the electrical and light signals generated by neutrinos as they crash into argon atoms. This information enables physicists to triangulate the positions of neutrinos and measure their properties. These panels will be submerged in liquid argon in one prototype, and the other prototype will test a newer technology which uses electron multipliers suspended in argon vapor.

In addition to building and testing the detector prototypes for LBNF/DUNE, CERN will serve as the European hub for neutrino physicists working on research based in the United States and elsewhere in the world. CERN has a rich history of neutrino research and contributed to past discoveries, such as the direct observation of neutrino shape-shifting made by the OPERA experiment at Gran Sasso laboratory in Italy. CERN also provides the infrastructure for DUNE researchers to build and test their detectors using CERN’s test beam facility. This is the first-time CERN joins projects located in the United States, with an active role designing final DUNE detectors and building the cryogenics infrastructure.

Fly above ProtoDUNE at CERN Neutrino Platform

Video above: Take a look at the CERN Neutrino platform with the eye of a drone. The huge red cube is the ProtoDUNE, a prototype for the DUNE detectors which will be installed in South-Dakota, USA, in the new Long-Baseline Neutrino Facility cavern. (Video: CERN).

“Things are changing,” Resnati said. “CERN’s mission is to seek answers to the big questions in physics, and we want to be part of this worldwide quest for knowledge. We’re pulling together as a global community of physicists and making it happen.”

The groundbreaking ceremony at Sanford Lab in South Dakota starting at 11:20 pm CEST will be webcast. Watch the webcast! http://go.web.cern.ch/go/Gsc8

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Long Baseline Neutrino Facility: http://lbnf.fnal.gov/

Neutrino Platform: http://home.cern/about/experiments/cern-neutrino-platform

For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/

Images (mentioned), Videos (mentioned), Text, Credits: CERN/Sarah Charley/Corinne Pralavorio.

Greetings, Orbiter.ch

Launch Preps in Kazakhstan; Cancer Therapies Researched on Station

ISS - Expedition 52 Mission patch.

July 24, 2017

International Space Station (ISS). Animation Credit: NASA

A new International Space Station crew is less than a week away from beginning a 4-1/2 month mission living and working in space. The trio from the United States, Russia and Italy is in Kazakhstan counting down to a Friday launch at 11:41 a.m. EDT inside the Soyuz MS-05 spacecraft.

Cosmonaut Sergey Ryazanskiy will command the Soyuz vehicle during the six-hour, 19-minute ride from Earth to the station’s Rassvet module. He will be flanked by crewmates Randy Bresnik of NASA and astronaut Paolo Nespoli from the European Space Agency. NASA TV will cover the launch and docking activities live.

Meanwhile, the Expedition 52 crew orbiting Earth now explored how microgravity impacts cancer therapies. The trio also worked on various maintenance tasks throughout the orbital lab.

Image above: Expedition 52-53 crew members (from left) Paolo Nespoli, Sergey Ryazanskiy and Randy Bresnik, stand in front of the Soyuz rocket that will launch them to space. Image Credits: Andrey Shelepin/Gagarin Cosmonaut Training Center.

New space research aboard the station is providing insights that may accelerate development of drugs that target only cancer cells. Flight Engineer Peggy Whitson peered at cells today through a microscope for the cancer study that started in April this year. Results may create more effective treatments for cancer patients on Earth.

Jack Fischer of NASA moved a variety of science gear around and cleaned a mouse habitat. He also swapped out a hard drive for an experiment that measures the composition of meteors orbiting and entering Earth’s atmosphere.

Related links:

Expedition 52: https://www.nasa.gov/mission_pages/station/expeditions/expedition52/index.html

Cancer study: https://www.nasa.gov/mission_pages/station/research/experiments/2347.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Animation (mentioned), Image (mentioned),  Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

Saturn Surprises As Cassini Continues its Grand Finale

NASA - Cassini Mission to Saturn patch.

July 24, 2017

Image above: This mosaic combines views captured by Cassini as it made the first dive of the mission's Grand Finale on April 26, 2017, and shows details in bands and swirls in the atmosphere. Image Credits: NASA/JPL-Caltech/SSI/Hampton University.

As NASA's Cassini spacecraft makes its unprecedented series of weekly dives between Saturn and its rings, scientists are finding -- so far -- that the planet's magnetic field has no discernable tilt. This surprising observation, which means the true length of Saturn's day is still unknown, is just one of several early insights from the final phase of Cassini's mission, known as the Grand Finale.

Other recent science highlights include promising hints about the structure and composition of the icy rings, along with high-resolution images of the rings and Saturn's atmosphere.

Image above: Recent images of features in Saturn's C ring called "plateaus" reveal a streaky texture that is very different from the textures of the regions around them. Image Credits: NASA/JPL-Caltech/Space Science Institute.

Cassini is now in the 15th of 22 weekly orbits that pass through the narrow gap between Saturn and its rings. The spacecraft began its finale on April 26 and will continue its dives until Sept. 15, when it will make a mission-ending plunge into Saturn's atmosphere.

"Cassini is performing beautifully in the final leg of its long journey," said Cassini Project Manager Earl Maize at NASA's Jet Propulsion Laboratory, Pasadena, California. "Its observations continue to surprise and delight as we squeeze out every last bit of science that we can get."

Image above: Recent images of features in Saturn's C ring called "plateaus" reveal a streaky texture that is very different from the textures of the regions around them. Image Credits: NASA/JPL-Caltech/Space Science Institute.

Cassini scientists are thrilled as well -- and surprised in some cases -- with the observations being made by the spacecraft in the finale. "The data we are seeing from Cassini's Grand Finale are every bit as exciting as we hoped, although we are still deep in the process of working out what they are telling us about Saturn and its rings," said Cassini Project Scientist Linda Spilker at JPL.

Early Magnetic Field Analysis

Based on data collected by Cassini's magnetometer instrument, Saturn's magnetic field appears to be surprisingly well-aligned with the planet's rotation axis. The tilt is much smaller than 0.06 degrees -- which is the lower limit the spacecraft's magnetometer data placed on the value prior to the start of the Grand Finale.

This observation is at odds with scientists' theoretical understanding of how magnetic fields are generated. Planetary magnetic fields are understood to require some degree of tilt to sustain currents flowing through the liquid metal deep inside the planets (in Saturn's case, thought to be liquid metallic hydrogen). With no tilt, the currents would eventually subside and the field would disappear.

Image above: Recent images of features in Saturn's C ring called "plateaus" reveal a streaky texture that is very different from the textures of the regions around them. Image Credits: NASA/JPL-Caltech/Space Science Institute.

Any tilt to the magnetic field would make the daily wobble of the planet's deep interior observable, thus revealing the true length of Saturn's day, which has so far proven elusive.

"The tilt seems to be much smaller than we had previously estimated and quite challenging to explain," said Michele Dougherty, Cassini magnetometer investigation lead at Imperial College, London. "We have not been able to resolve the length of day at Saturn so far, but we're still working on it."

The lack of a tilt may eventually be rectified with further data. Dougherty and her team believe some aspect of the planet's deep atmosphere might be masking the true internal magnetic field. The team will continue to collect and analyze data for the remainder of the mission, including during the final plunge into Saturn.

Image above: This colorful spectrogram represents data collected by Cassini's Radio and Plasma Wave Science instrument as it crossed through Saturn's D ring on May 28, 2017. Image Credits: NASA/JPL-Caltech/University of Iowa.

The magnetometer data will also be evaluated in concert with Cassini's measurements of Saturn's gravity field collected during the Grand Finale. Early analysis of the gravity data collected so far shows discrepancies compared with parts of the leading models of Saturn's interior, suggesting something unexpected about the planet's structure is awaiting discovery.

Sampling Saturn

In addition to its investigation of the planet's interior, Cassini has now obtained the first-ever samples of the planet's atmosphere and main rings, which promise new insights about their composition and structure. The spacecraft's cosmic dust analyzer (CDA) instrument has collected many nanometer-size ring particles while flying through the planet-ring gap, while its ion and neutral mass spectrometer (INMS) has sniffed the outermost atmosphere, called the exosphere.

During Cassini's first dive through the gap on April 26, the spacecraft was oriented so its large, saucer-shaped antenna would act as a shield against oncoming ring particles that might cause damage. While at first it appeared that there were essentially no particles in the gap, scientists later determined the particles there are very small and could be detected using the CDA instrument.

Image above: This false-color view from NASA's Cassini spacecraft gazes toward the rings beyond Saturn's sunlit horizon, where a thin haze can be seen along the limb. Image Credits: NASA/JPL-Caltech/Space Science Institute.

The cosmic dust analyzer was later allowed to peek out from behind the antenna during Cassini's third of four passes through the innermost of Saturn's main rings, the D ring, on June 29. During Cassini's first two passes through the inner D ring, the particle environment there was found to be benign. This prompted mission controllers to relax the shielding requirement for one orbit, in hopes of capturing ring particles there using CDA. As the spacecraft passed through the ring, the CDA instrument successfully captured some of the tiniest particles there, which the team expects will provide significant information about their composition.

During the spacecraft's final five orbits, as well as it final plunge, the INMS instrument will obtain samples deeper down in the atmosphere. Cassini will skim through the outer atmosphere during these passes, and INMS is expected to send particularly important data on the composition of Saturn's atmosphere during the final plunge.

Cassini Grand Finale. Animation Credits: NASA/JPL-Caltech/Space Science Institute

Amazing Images

Not to be outdone, Cassini's imaging cameras have been hard at work, returning some of the highest-resolution views of the rings and planet they have ever obtained. For example, close-up views of Saturn's C ring -- which features mysterious bright bands called plateaus -- reveal surprisingly different textures in neighboring sections of the ring. The plateaus appear to have a streaky texture, whereas adjacent regions appear clumpy or have no obvious structure at all. Ring scientists believe the new level of detail may shed light on why the plateaus are there, and what is different about the particles in them.

On two of Cassini's close passes over Saturn, on April 26 and June 29, the cameras captured ultra-close views of the cloudscape racing past, showing the planet from closer than ever before. Imaging scientists have combined images from these dives into two new image mosaics and a movie sequence. (Specifically, the previously released April 26 movie was updated to greatly enhance its contrast and sharpness.)

Image above: Cassini captured the near-infrared images in this mosaic on June 29, 2017, as it raced toward the gap between Saturn and its rings. Image Credits: NASA/JPL-Caltech/SSI/Hampton University.

Launched in 1997, Cassini has orbited Saturn since arriving in 2004 for an up-close study of the planet, its rings and moons, and its vast magnetosphere. Cassini has made numerous dramatic discoveries, including a global ocean with indications of hydrothermal activity within the moon Enceladus, and liquid methane seas on another moon, Titan.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.

More information about the Cassini mission:

https://www.nasa.gov/cassini

https://saturn.jpl.nasa.gov

http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Preston Dyches.

Best regards, Orbiter.ch