NASA Provides New Look at Puerto Rico Post-Hurricane Maria

NASA - Suomi NPP Mission patch.

Dec. 10, 2018

When Hurricane Maria struck Puerto Rico head-on as a Category 4 storm with winds up to 155 miles per hour in September 2017, it damaged homes, flooded towns, devastated the island's forests and caused the longest electricity black-out in U.S. history.

Image above: On Sept. 21, 2017, NASA-NOAA's Suomi NPP satellite provided this thermal image of Hurricane Maria after it moved off the coast of Puerto Rico. Image Credit: NOAA/NASA Goddard Rapid Response Team.

Two new NASA research efforts delve into Hurricane Maria's far-reaching effects on the island's forests as seen in aerial surveys and on its residents' energy and electricity access as seen in data from space. The findings, presented Monday at the American Geophysical Union meeting in Washington, illustrate the staggering scope of Hurricane Maria's damage to both the natural environment and communities.

An Island Gone Dark

At night, Earth is lit up in bright strings of roads dotted with pearl-like cities and towns as human-made artificial light takes center stage. During Hurricane Maria, Puerto Rico's lights went out.

In the days, weeks and months that followed, research physical scientist Miguel Román at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and his colleagues developed neighborhood-scale maps of lighting in communities across Puerto Rico. To do this, they combined daily satellite data of Earth at night from the NASA/NOAA Suomi National Polar-orbiting Partnership satellite with USGS/NASA Landsat data and OpenStreetMap data. They monitored where and when the electricity grid was restored, and analyzed the demographics and physical attributes of neighborhoods longest affected by the power outages.

NASA's Black Marble Maps Puerto Rico's Energy Use After Hurricane Maria

Video above: Credits: NASA's Goddard Space Flight Center.

A disproportionate share of long-duration power failures occurred in rural communities. The study found that 41 percent of Puerto Rico’s rural municipalities experienced prolonged periods of outage, compared to 29 percent of urban areas. When combined, power failures across Puerto Rico’s rural communities accounted for 61 percent of the estimated cost of 3.9 billion customer-interruption hours, six months after Hurricane Maria. These regions are primarily rural in the mountainous interior of the island where residents were without power for over 120 days. However, even more heavily populated areas had variable recovery rates between neighborhoods, with suburbs often lagging behind urban centers.

The difference between urban and rural recovery rates is in part because of the centralized set-up of Puerto Rico's energy grid that directs all power to prioritized locations rather than based on proximity to the nearest power plant, Román said. Areas were prioritized, in part, based on their population densities, which is a disadvantage to rural areas. Within cities, detached houses and low-density suburban areas were also without power longer.

"It’s not just the electricity being lost," Román said. "Storm damage to roads, high-voltage power lines and bridges resulted in cascading failures across multiple sectors, making many areas inaccessible to recovery efforts. So people lost access to other basic services like running water, sanitation, and food for extended time periods."

The absence of electricity as seen in the night lights data offers a new way to visualize storm impacts to vulnerable communities across the entirety of Puerto Rico on a daily basis. It's an indicator visible from space that critical infrastructure, beyond power, may be damaged as well, including access to fuel and other necessary supplies. The local communities with long-duration power outages also correspond to areas that reported lack of access to medical resources.

The next step for Román when looking at future disasters is to go beyond night lights data and sync it up with updated information on local infrastructure – roads, bridges, internet connectivity, clean water sources – so that when the lights are out, disaster responders can cross-reference energy data with other infrastructure bottlenecks that needs to be solved first, which would help identify at-risk communities and allocate resources.

The Buzz-Cut Forest

Hurricane Maria's lashing rain and winds also transformed Puerto Rico's lush tropical rainforest landscape. Research scientist Doug Morton of Goddard was part of the team of NASA researchers who had surveyed Puerto Rico's forests six months before the storm. The team used Goddard’s Lidar, Hyperspectral, and Thermal (G-LiHT) Airborne Imager, a system designed to study the structure and species composition of forests. Shooting 600,000 laser pulses per second, G-LiHT produces a 3D view of the forest structure in high resolution, showing individual trees in high detail from the ground to treetop. In April 2018, post-Maria, the team went back and surveyed the same tracks as in 2017.

Comparing the before and after data, the team found that 40 to 60 percent of the tall trees that formed the canopy of the forest were damaged, either snapped in half, uprooted by strong winds or lost large branches.

3-D Views of Puerto Rico's Forests After Hurricane Maria

Video above: Credits: NASA's Goddard Space Flight Center.

"Maria gave the island's forests a haircut," said Morton. "The island lost so many large trees that the overall height of forests was shortened by one-third. We basically saw 60 years' worth of what we would otherwise consider natural treefall disturbances happen in one day."

The extensive damage to Puerto Rico's forests had far-reaching effects, Morton said. Fallen trees that no longer stabilize soil on slopes with their roots as well as downed branches can contribute to landslides and debris flows, increased erosion, and poor water quality in streams and rivers where sediments build up.

In addition, the lidar surveys across the island corroborate findings presented at AGU by ecologist Maria Uriarte at Columbia University in New York City, who looked at tree death and damage rates in ground plots at the National Science Foundation Luquillo Long-Term Ecological Research site. Uriarte found certain tree species were more susceptible to the high wind damage, while others such as the palms, survived at higher rates, along with shrubs and shorter trees in the understory.

Morton and Uriarte will continue to follow the fate of Puerto Rican forests as they recover from hurricane damages using laser technology from the ground to make detailed measurements of forest regrowth.

Related articles:

NASA Measures Hurricane Maria's Torrential Rainfall, Sees Eye Re-open
https://orbiterchspacenews.blogspot.com/2017/09/nasa-measures-hurricane-marias.html

NASA Looks Within Category 5 Hurricane Maria Before and After First Landfall
https://orbiterchspacenews.blogspot.com/2017/09/nasa-looks-within-category-5-hurricane.html

NASA Sees Maria Intensify into a Major Hurricane
https://orbiterchspacenews.blogspot.com/2017/09/nasa-sees-maria-intensify-into-major.html

NASA Finds Very Heavy Rainfall in Hurricane Maria
https://orbiterchspacenews.blogspot.com/2017/09/nasa-finds-very-heavy-rainfall-in.html

NASA Infrared Data Targets Maria's Strongest Side
https://orbiterchspacenews.blogspot.com/2017/09/nasa-infrared-data-targets-marias.html

For more information on NASA's Black Marble data, visit: https://viirsland.gsfc.nasa.gov/Products/NASA/BlackMarble.html

For more information on NASA's G-LiHT data: https://gliht.gsfc.nasa.gov/

Suomi NPP (National Polar-orbiting Partnership): http://www.nasa.gov/mission_pages/NPP/main/index.html

Image (mentioned), Videos (mentioned), Text, Credits: NASA/Sara Blumberg/Earth Science News Team, by Ellen Gray.

Greetings, Orbiter.ch

Improved Membrane Technology Creates Tiny Pores with Big Impact

ISS - International Space Station logo.

Dec. 10, 2018

Membranes – thin barriers that allow some things to pass through, but stop others – occur naturally in cells and tissues. Artificial membranes modeled after natural ones are used in a number of applications, including separating and removing carbon dioxide (CO₂) from waste gases released in energy production.

An investigation on the International Space Station looks at whether making artificial membranes in microgravity can help reduce greenhouse gas emissions on Earth.

Image above: Cemsica calcium silicate nanoparticles, which have diameters as small as a few nanometers. Image Credits: Cemsica.

The Cemsica investigation uses particles of calcium-silicate to make membranes with openings or pores smaller than 100 nanometers, known as nanoporous membranes, to separate carbon dioxide molecules from air and other gases. These membranes are as thin as a human hair. Membranes already represent one of the most energy-efficient and cost-effective technologies for separating and removing CO₂ from waste gases.

The investigation takes its name from Houston-based Cemsica, LLC, a company that is commercializing this gas separation membrane technology. “Our technology not only controls the shape and size of the membrane pores,” said Negar Rajabi, principal investigator and Cemsica founder and CEO. “It also creates an affinity to certain gases such as CO₂, meaning those gases are drawn to the membrane.” That gives the membranes significantly greater separation capability.

Creating these membranes in microgravity may resolve current challenges in the technology, including high-cost and manufacturing difficulties, Rajabi added. Resolving those challenges could lead to development of lower-cost membranes with improved performance and stability, as well as improved manufacturing techniques.

Large gaps or separation of the calcium-silicate particles and substrate material adversely affect membrane performance. Microgravity minimizes these problems since calcium-silicate crystals grow larger and in more organized structures in space, creating organized, defect-free pores and higher surface area.

Image above: The rise of carbon dioxide in the atmosphere. In 2013, CO₂ levels surpassed 400 ppm for the first time in recorded history. Image Credits: National Oceanic and Atmospheric Administration.

Surface area plays a key role in gas separation in microgravity, where separation occurs only through diffusion. The higher surface area remains a significant factor in improved gas separation even in Earth’s gravity because it creates higher surface tension that facilitates affinity-based gas separation.

This investigation was sponsored by the International Space Station U.S. National Laboratory. “Cemsica’s novel approach to gas separation membranes in microgravity conditions provides the energy community a new avenue for evaluating unique ways to reduce the effects of CO₂ emissions on our planet,” said Patrick O’Neill with the National Lab. “The project also could reduce energy consumption while improving the chemical stability of products on Earth.”

Lessons learned from the investigation may enable Earth-based production of membranes that can separate and capture CO₂ from fossil-fuel power plants using half the energy of current methods. Roughly 40 percent of CO₂ emissions in the U.S. come from these power plants. Other potential applications include oil and gas production and water treatment.

These membrane pores may be tiny, but they have very big potential.

Related links:

Cemsica, LLC: http://www.cemsica.com/

International Space Station U.S. National Laboratory: http://www.iss-casis.org/

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/Michael Johnson/JSC/International Space Station Program Science Office/Melissa Gaskill.

Best regards, Orbiter.ch

LHC prepares for new achievements

CERN - European Organization for Nuclear Research logo.

Dec. 10, 2018

After an outstanding performance, the Large Hadron Collider (LHC), the accelerator complex and the experiments are now stopping for two years for major improvements and upgrading.

Image above: The Superconducting Magnets and Circuits Consolidation project which took place during the first Long Shutdown (LS1) (Image: Maximilien Brice/CERN).

Geneva, 3 December 2018. Early this morning, operators of the CERN Control Centre turned off the Large Hadron Collider (LHC), ending the very successful second run of the world’s most powerful particle accelerator. CERN’s accelerator complex will be stopped for about two years to enable major upgrade and renovation works.

During this second run (2015–2018), the LHC performed beyond expectations, achieving approximately 16 million billion proton-proton collisions at an energy of 13 TeV and large datasets for lead-lead collisions at an energy of 5.02 TeV. These collisions produced an enormous amount of data, with more than 300 petabytes (300 million gigabytes) now permanently archived in CERN’s data centre tape libraries. This is the equivalent of 1000 years of 24/7 video streaming! By analysing these data, the LHC experiments have already produced a large amount of results, extending our knowledge of fundamental physics and of the Universe.

“The second run of the LHC has been impressive, as we could deliver well beyond our objectives and expectations, producing five times more data than during the first run, at the unprecedented energy of 13 TeV,” says Frédérick Bordry, CERN Director for Accelerators and Technology. “With this second long shutdown starting now, we will prepare the machine for even more collisions at the design energy of 14 TeV.”

“In addition to many other beautiful results, over the past few years the LHC experiments have made tremendous progress in the understanding of the properties of the Higgs boson,” adds Fabiola Gianotti, CERN Director-General. “The Higgs boson is a special particle, very different from the other elementary particles observed so far; its properties may give us useful indications about physics beyond the Standard Model.”

A cornerstone of the Standard Model of particle physics – the theory that best describes the elementary particles and the forces that bind them together – the Higgs boson was discovered at CERN in 2012 and has been studied ever since. In particular, physicists are analysing the way it decays or transforms into other particles, to check the Standard Model’s predictions. Over the last three years, the LHC experiments extended the measurements of rates of Higgs boson decays, including the most common, but hard-to-detect, decay into bottom quarks, and the rare production of a Higgs boson in association with top quarks. The ATLAS and CMS experiments also presented updated measurement of the Higgs boson mass with the best precision to date.

Besides the Higgs boson, the LHC experiments produced a wide range of results and hundreds of scientific publications, including the discovery of exotic new particles such as Ξcc++ and pentaquarks with the LHCb experiment, and the unveiling of so-far unobserved phenomena in proton–proton and proton-lead collisions at ALICE.

During the two-year break, Long Shutdown 2 (LS2), the whole accelerator complex and detectors will be reinforced and upgraded for the next LHC run, starting in 2021, and the High-Luminosity LHC (HL-LHC) project, which will start operation after 2025. Increasing the luminosity of the LHC means producing far more data.

“The rich harvest of the second run enables the researchers to look for very rare processes,” explains Eckhard Elsen, Director for Research and Computing at CERN. “They will be busy throughout the shutdown examining the huge data sample for possible signatures of new physics that haven’t had the chance to emerge from the dominant contribution of the Standard Model processes. This will guide us into the HL-LHC when the data sample will increase by yet another order of magnitude.”

Large Hadron Collider (LHC)

Several components of the accelerator chain (injectors) that feed the LHC with protons will be renewed to produce more intense beams. The first link in this chain, the linear accelerator Linac2, will be replaced by Linac4. The new linear accelerator will accelerate H- ions, which are later stripped to protons, allowing the preparation of brighter beams. The second accelerator in the chain, the Proton Synchrotron Booster, will be equipped with completely new injection and acceleration systems. The Super Proton Synchrotron (SPS), the last injector before the LHC, will have new radio frequency power to accelerate higher beam intensities, and will be connected to upgraded transfer lines.

Some improvements of the LHC are also planned during LS2. The bypass diodes – the electrical components that protect the magnets in case of quench – will be shielded, as a prerequisite for extending the LHC beam energy to 7 TeV after the LS2, and more than 20 main superconducting magnets will be replaced. Moreover, civil engineering works for the HL-LHC that started in June 2018 will continue, new galleries will be connected to the LHC tunnel, and new powerful magnet and superconducting technologies will be tested for the first time.

All the LHC experiments will upgrade important parts of their detectors in the next two years. Almost the entire LHCb experiment will be replaced with faster detector components that will enable the collaboration to record events at full proton-proton rate. Similarly, ALICE will upgrade the technology of its tracking detectors. ATLAS and CMS will undergo improvements and start to prepare for the big experiments’ upgrade for HL-LHC.

Proton beams will resume in spring 2021 with the LHC’s third run.

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:

Higgs boson: https://home.cern/science/physics/higgs-boson

ATLAS paper: https://arxiv.org/pdf/1806.00242.pdf

CMS paper: https://arxiv.org/abs/1706.09936

High-Luminosity LHC (HL-LHC) project: https://home.cern/science/accelerators/high-luminosity-lhc

Linac2: https://home.cern/news/news/accelerators/so-long-linac2-and-thanks-all-protons

Large Hadron Collider (LHC): https://home.web.cern.ch/fr/topics/large-hadron-collider

ATLAS: https://home.web.cern.ch/about/experiments/atlas

CMS: https://home.web.cern.ch/about/experiments/cms

ALICE: https://home.web.cern.ch/about/experiments/alice

LHCb: https://home.web.cern.ch/about/experiments/lhcb

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

Image, Animation, Text, Credit: CERN.

Best regards, Orbiter.ch

NASA’s Newly Arrived OSIRIS-REx Spacecraft Already Discovers Water on Asteroid

NASA - OSIRIS-REx Mission patch.

Dec. 10, 2018

Image above: This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24km). Image Credits: NASA/Goddard/University of Arizona.

Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.

During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.

Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.

OSIRIS-REx arrival at Bennu. Animation Credit: NASA

“The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”

Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.

One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).

Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.

3D Shape Model of Asteroid Bennu

Video above: This preliminary shape model of asteroid Bennu was created from a compilation of images taken by OSIRIS-REx’s PolyCam camera during the spacecraft’s approach toward Bennu during the month of November. This 3D shape model shows features on Bennu as small as six meters. Video Credits: NASA/Goddard/University of Arizona.

“Our initial data show that the team picked the right asteroid as the target of the OSIRIS-REx mission. We have not discovered any insurmountable issues at Bennu so far,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “The spacecraft is healthy and the science instruments are working better than required. It is time now for our adventure to begin.”

The mission currently is performing a preliminary survey of the asteroid, flying the spacecraft in passes over Bennu’s north pole, equator, and south pole at ranges as close as 4.4 miles (7 km) to better determine the asteroid’s mass. The mission’s scientists and engineers must know the mass of the asteroid in order to design the spacecraft’s insertion into orbit because mass affects the asteroid’s gravitational pull on the spacecraft. Knowing Bennu’s mass will also help the science team understand the asteroid’s structure and composition.

This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations, now that the spacecraft is in proximity to Bennu.

The spacecraft’s first orbital insertion is scheduled for Dec. 31, and OSIRIS-REx will remain in orbit until mid-February 2019, when it exits to initiate another series of flybys for the next survey phase. During the first orbital phase, the spacecraft will orbit the asteroid at a range of 0.9 miles (1.4 km) to 1.24 miles (2.0 km) from the center of Bennu — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.

Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.

For more information about OSIRIS-REx, visit: https://www.nasa.gov/osiris-rex

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/Katherine Brown/GSFC/Nancy Jones/University of Arizona/Erin Morton.

Greetings, Orbiter.ch

NASA’s Voyager 2 Probe Enters Interstellar Space

NASA - Voyager 1 & 2 Mission patch.

Dec. 10, 2018

Image above: This illustration shows the position of NASA’s Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Image Credits: NASA/JPL-Caltech.

For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.

Members of NASA’s Voyager team will discuss the findings at a news conference at 11 a.m. EST (8 a.m. PST) today at the meeting of the American Geophysical Union (AGU) in Washington. The news conference will stream live on the agency’s website.

NASA’s Voyager 2 Enters Interstellar Space

Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.

Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.

The most compelling evidence of Voyager 2’s exit from the heliosphere came from its onboard Plasma Science Experiment (PLS), an instrument that stopped working on Voyager 1 in 1980, long before that probe crossed the heliopause. Until recently, the space surrounding Voyager 2 was filled predominantly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble – the heliosphere – that envelopes the planets in our solar system. The PLS uses the electrical current of the plasma to detect the speed, density, temperature, pressure and flux of the solar wind. The PLS aboard Voyager 2 observed a steep decline in the speed of the solar wind particles on Nov. 5. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has left the heliosphere.

In addition to the plasma data, Voyager’s science team members have seen evidence from three other onboard instruments – the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer – that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager’s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is traveling.

Image above: The set of graphs on the left illustrates the drop in electrical current detected in three directions by Voyager 2's plasma science experiment (PLS) to background levels. They are among the key pieces of data that show that Voyager 2 entered interstellar space in November 2018. Image Credits: NASA/JPL-Caltech/MIT.

“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.

Together, the two Voyagers provide a detailed glimpse of how our heliosphere interacts with the constant interstellar wind flowing from beyond. Their observations complement data from NASA’s Interstellar Boundary Explorer (IBEX), a mission that is remotely sensing that boundary. NASA also is preparing an additional mission – the upcoming Interstellar Mapping and Acceleration Probe (IMAP), due to launch in 2024 – to capitalize on the Voyagers’ observations.

“Voyager has a very special place for us in our heliophysics fleet,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. “Our studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun’s influence gives us an unprecedented glimpse of truly uncharted territory.”

While the probes have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won’t be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the Oort Cloud, a collection of small objects that are still under the influence of the Sun’s gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units (AU) from the Sun and to extend to about 100,000 AU. One AU is the distance from the Sun to Earth. It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.

The Voyager probes are powered using heat from the decay of radioactive material, contained in a device called a radioisotope thermal generator (RTG). The power output of the RTGs diminishes by about four watts per year, which means that various parts of the Voyagers, including the cameras on both spacecraft, have been turned off over time to manage power.

“I think we’re all happy and relieved that the Voyager probes have both operated long enough to make it past this milestone,” said Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “This is what we've all been waiting for. Now we’re looking forward to what we’ll be able to learn from having both probes outside the heliopause.”

Voyager 2 launched in 1977, 16 days before Voyager 1, and both have traveled well beyond their original destinations. The spacecraft were built to last five years and conduct close-up studies of Jupiter and Saturn. However, as the mission continued, additional flybys of the two outermost giant planets, Uranus and Neptune, proved possible. As the spacecraft flew across the solar system, remote-control reprogramming was used to endow the Voyagers with greater capabilities than they possessed when they left Earth. Their two-planet mission became a four-planet mission. Their five-year lifespans have stretched to 41 years, making Voyager 2 NASA’s longest running mission.

The Voyager story has impacted not only generations of current and future scientists and engineers, but also Earth's culture, including film, art and music. Each spacecraft carries a Golden Record of Earth sounds, pictures and messages. Since the spacecraft could last billions of years, these circular time capsules could one day be the only traces of human civilization.

Voyager’s mission controllers communicate with the probes using NASA’s Deep Space Network (DSN), a global system for communicating with interplanetary spacecraft. The DSN consists of three clusters of antennas in Goldstone, California; Madrid, Spain; and Canberra, Australia.

The Voyager Interstellar Mission is a part of NASA’s Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA’s Science Mission Directorate in Washington. JPL built and operates the twin Voyager spacecraft. NASA’s DSN, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions. The Commonwealth Scientific and Industrial Research Organisation, Australia’s national science agency, operates both the Canberra Deep Space Communication Complex, part of the DSN, and the Parkes Observatory, which NASA has been using to downlink data from Voyager 2 since Nov. 8.

Related article:

NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble'
https://orbiterchspacenews.blogspot.com/2013/06/nasas-voyager-1-explores-final-frontier.html

Related links:

Interstellar Boundary Explorer (IBEX): https://www.nasa.gov/mission_pages/ibex/index.html

Interstellar Mapping and Acceleration Probe (IMAP): https://www.nasa.gov/press-release/nasa-selects-mission-to-study-solar-wind-boundary-of-outer-solar-system

Deep Space Network (DSN): https://www.nasa.gov/directorates/heo/scan/services/networks/dsn

For more information about the Voyager mission, visit: https://www.nasa.gov/voyager

More information about NASA’s Heliophysics missions is available online at: https://www.nasa.gov/sunearth

Images (mentioned), Animations, Video, Text, Credits: NASA/Dwayne Brown/Karen Fox/Sean Potter/JPL/Calla Cofield.

Best regards, Orbiter.ch

Jupiter's North Equatorial Belt

NASA - JUNO Mission logo.

Dec. 10, 2018

Colorful swirling clouds in Jupiter's North Equatorial Belt practically fill this image from NASA's Juno spacecraft. This is the closest image captured of the Jovian clouds during this recent flyby of the gas giant planet.

The color-enhanced image was taken at 2:08 p.m. PDT (5:08 p.m. EDT) on Oct. 29, 2018 as the spacecraft performed its 16th close flyby of Jupiter. At the time, Juno was about 2,100 miles (3,400 kilometers) from the planet's cloud tops, at approximately 14 degrees north latitude. In other words, the spacecraft was about as close to Jupiter as San Francisco is to Chicago, which is quite close when racing over a planet that's 11 times wider than Earth.

Juno spacecraft orbiting Jupiter

Citizen scientist Björn Jónsson created this image using data from the spacecraft's JunoCam imager.

JunoCam's raw images are available for the public to peruse and to process into image products at: http://missionjuno.swri.edu/junocam.  

More information about Juno is at: http://www.nasa.gov/juno and http://missionjuno.swri.edu.

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ULA - Delta 4-Heavy countdown aborted moments before launch

ULA - NROL-71 Mission patch.

Dec. 9, 2018

Image above: The mobile service tower retracts into position for launch during a countdown Dec. 8. Image Credit: United Launch Alliance.

A dramatic automatic abort 7.5 seconds before the planned liftoff of a United Launch Alliance Delta 4-Heavy rocket Saturday night kept the towering launcher on the pad at Vandenberg Air Force Base, California, with a top secret spy payload for the National Reconnaissance Office.

The 233-foot-tall (71-meter) rocket was counting down to launch at 8:15 p.m. PST Saturday (11:15 p.m. PST; 0415 GMT Sunday), but an automated sequencer detected a technical issue and triggered an abort.

Delta 4-Heavy countdown aborted moments before launch

“Hold hold hold,” a member of the ULA launch team declared on the countdown net.

A burst of flame appeared at the base of the rocket, a normal occurrence in the final seconds of a Delta 4 countdown as sparklers activate near the engines to burn off excess hydrogen gas before ignition, a measure aimed at eliminating the risk of a fireball or explosion.

It was not immediately clear whether any of the rocket’s three Aerojet Rocketdyne RS-68A main engines started their ignition sequences, but a statement later released by ULA said the computer-controlled countdown sequencer ordered an abort at T-minus 7.5 seconds.

In the statement, ULA said the abort was “due to an unexpected condition during terminal count at approximately 7.5 seconds before liftoff.

Image above: The mobile service tower retracts into position for launch during a countdown Dec. 8. Image Credit: United Launch Alliance.

“The team is currently reviewing all data and will determine the path forward. A new launch date will be provided when available,” ULA said.

The Delta 4-Heavy is made up of three Delta 4 first stage boosters bolted together, each with an RS-68A engine burning liquid hydrogen and liquid oxygen propellants. ULA commands the three RS-68A engines to start in a staggered sequence, beginning with the starboard engine at T-minus 7 seconds, followed two seconds later by ignition of the center and port engines.

The timing of the abort at T-minus 7.5 seconds suggests the countdown stopped around a half-second before the first of the Delta 4-Heavy’s three main engines was supposed to ignite.

ULA’s launch team quickly “safed” the rocket, disarmed ordnance, and drained the Delta 4-Heavy of its supply of cryogenic propellants. The launch team did not set a new target launch date, but officials were instructed to plan for an extended turnaround after Saturday night’s scrub, and the Delta 4-Heavy flight was expected to be delayed at least a few days.

Image above: The mobile service tower retracts into position for launch during a countdown Dec. 7. Image Credit: United Launch Alliance.

A similar cutoff in the final seconds of a Delta 4 countdown in 2010 resulted in a three-day slip to resolve the problem responsible for the abort — and replace the hydrogen burn-off sparklers on the pad — before the rocket successfully launched from Cape Canaveral with a GPS navigation satellite.

The upcoming mission from Vandenberg, located around 140 miles (225 kilometers) northwest of Los Angeles, is codenamed NROL-71 by the National Reconnaissance Office, which owns the U.S. government’s classified intelligence-gathering satellites. The NRO has not released any information about the spacecraft aboard the Delta 4-Heavy, but independent observers of NRO space launches believe the payload is heading for an unusual, high-inclination orbit, and is likely a new Keyhole-type high-resolution optical imaging satellite, with an Earth-pointing telescope capable of capturing extremely detailed imagery of sites around the world for review by government intelligence analysts.

The Delta 4-Heavy is ULA’s biggest rocket, and can loft up to 51,950 pounds (23,560 kilograms) of payload mass to a 120-mile-high (200-kilometer) low Earth orbit inclined 90 degrees to the equator.

The heavy-lift variant of the Delta 4 rocket has launched 10 times to date. The NROL-71 mission will be the 11th flight of a Delta 4-Heavy, and the 38th mission overall for the Delta 4 family since November 2002. It will also be ULA’s ninth and final launch of the year, following five Atlas 5 launches, a pair of Delta 4s, and the final liftoff of the company’s now-retired Delta 2 rocket.

A launch attempt for the NROL-71 mission Friday night was scrubbed after the Delta 4 team encountered a problem with a communications link between the control center and the rocket associated with the holdfire system.

For more information about United Launch Alliance (ULA): https://www.ulalaunch.com/

Images (mentioned), Video, Text, Credits: ULA/Spaceflight Now.com/Stephen Clark.

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