vendredi 26 mai 2017

First Year of BEAM Demo Offers Valuable Data on Expandable Habitats












ISS - International Space Station logo.

May 26, 2017

 Bigelow Expandable Activity Module on ISS. Image Credit: NASA

Halfway into its planned two-year demonstration attached to the International Space Station, the Bigelow Expandable Activity Module, or BEAM, is showing that soft materials can perform as well as rigid materials for habitation volumes in space. The BEAM was launched and attached to station through a partnership between NASA’s Advanced Exploration Systems Division (AES) and Bigelow Aerospace, headquartered in North Las Vegas, Nevada.

NASA and Bigelow are primarily evaluating characteristics directly related to the module’s ability to protect humans from the harsh space environment. Astronauts aboard station work with researchers on the ground to monitor the module’s structural integrity, thermal stability, and resistance to space debris, radiation, and microbial growth.

Researchers at NASA’s Langley Research Center in Hampton, Virginia, continually analyze data from internal sensors designed to monitor and locate external impacts by orbital debris, and, as expected, have recorded a few probable micrometeoroid debris impacts so far. BEAM has performed as designed in preventing debris penetration with multiple outer protective layers exceeding space station shielding requirements.


Image above: Astronauts aboard the space station 3-D printed a shield to cover one of the two Radiation Environment Monitors inside the BEAM. The shield, the white hemispherical shape at the center of the photograph, is shown above inside the BEAM module. In the coming months, the crew will print successively thicker shields to determine the shielding effectiveness at blocking radiation. Image Credit: NASA.

Over the next several months, NASA and Bigelow will focus on measuring radiation dosage inside the BEAM. Using two active Radiation Environment Monitors (REM) inside the module, researchers at NASA’s Johnson Space Center in Houston are able to take real-time measurements of radiation levels. They have found that Galactic Cosmic Radiation (GCR) dose rates inside the BEAM are similar to other space station modules, and continue to analyze contributions to the daily dose from the Earth’s trapped radiation belts to better understand the shielding properties of the module for application to long-term missions. The space station and the BEAM enjoy a significant amount of protection from Earth’s magnetosphere. Future deep space missions will be far more exposed to energized radiation particles speeding through the solar system, so NASA is actively working on ways to mitigate the effects of radiation events.

In late April, NASA’s radiation researchers at Johnson began a multi-month BEAM radiation experiment by installing a .04 inch (1.1 mm) thick shield onto one of the two REM sensors in BEAM. The station crew produced a hemispherical shield using the 3-D printer on the space station, and in the next few months this first shield will be replaced by two successively thicker shields, also 3-D printed, with thicknesses of about .13 inches (3.3mm) and .4 inches (10mm), respectively. The difference in measurements from the two REMs—one with a shield and one without—will help better resolve the energy spectra of the trapped radiation particles, particularly those coming from the South Atlantic Anomaly.


Image above: Peggy Whitson and Thomas Pesquet inside the BEAM module. Image Credit: NASA.

Space station crew members have entered the BEAM nine times since its expansion in May 2016. In addition to the REM shielding experiment activities, the crew has swapped out passive radiation badges called Radiation Area Monitors and they routinely collect microbial air and surface samples. These badges and samples are sent back to Earth for standard microbial and radiation analysis at Johnson.

The BEAM technology demonstration is helping NASA to advance and learn about expandable space habitat technology in low-Earth orbit for application toward future human exploration missions. The partnership between NASA and Bigelow supports NASA’s objective to develop a deep space habitat for human missions beyond Earth orbit while fostering commercial capabilities for non-government applications.

Related links:

NASA’s Advanced Exploration Systems Division (AES): https://www.nasa.gov/directorates/heo/aes/index.html

Bigelow Expandable Activity Module (BEAM): https://www.nasa.gov/content/bigelow-expandable-activity-module

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

Images (mentioned), Text, Credits: NASA/Erin Mahoney.

Greetings, Orbiter.ch

New NASA Mission to Study Mysterious Neutron Stars, Aid in Deep Space Navigation












ISS - International Space Station patch.

May 26, 2017

A new NASA mission is headed for the International Space Station next month to observe one of the strangest observable objects in the universe.

Launching June 1, the Neutron Star Interior Composition Explorer (NICER) will be installed aboard the space station as the first mission dedicated to studying neutron stars, a type of collapsed star that is so dense scientists are unsure how matter behaves deep inside it.

A neutron star begins its life as a star between about seven and 20 times the mass of our sun. When this type of star runs out of fuel, it collapses under its own weight, crushing its core and triggering a supernova explosion. What remains is an ultra-dense sphere only about 12 miles (20 kilometers) across, the size of a city, but with up to twice the mass of our sun squeezed inside. On Earth, one teaspoon of neutron star matter would weigh a billion tons.

"If you took Mount Everest and squeezed it into something like a sugar cube, that's the kind of density we're talking about," said Keith Gendreau, the principal investigator for NICER at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Unlocking Secrets of Neutron Stars with NICER

Video above: Though we know neutron stars are small and extremely dense, there are still many aspects of these remnants of explosive deaths of other stars that we have yet to understand. NICER, a facility to be mounted on the outside of the International Space Station, seeks to find the answers to some of the questions still being asked about neutron stars. By capturing the arrival time and energy of the X-ray photons produced by pulsars emitted by neutron stars, NICER seeks to answer decades-old questions about extreme forms of matter and energy. Data from NICER will also be used in SEXTANT, an on-board demonstration of pulsar-based navigation. Video Credits: NASA's Johnson Space Center.

Because neutron stars are so dense, scientists are uncertain how matter behaves in their interiors. In everyday experience, objects are composed of atoms. When neutron stars form, their atoms become crushed together and merge. As a result, the bulk of a neutron star is made up of tightly packed subatomic particles — primarily neutrons, as well as protons and electrons, in various states. NICER measurements will help scientists better understand how matter behaves in this environment.

"As soon as you go below the surface of a neutron star, the pressures and densities rise extremely rapidly, and soon you're in an environment that you can't produce in any lab on Earth," said Columbia University research scientist Slavko Bogdanov, who leads the NICER light curve modeling group.

The only object known to be denser than a neutron star is its dark cousin, the black hole. A black hole forms when a star more than approximately 20 times the mass of our sun collapses. A black hole's powerful gravity establishes a barrier known as an event horizon, which prevents direct observation. So scientists turn to neutron stars to study matter at nature's most extreme observable limit.



Image above: Animated still image of the NICER payload aboard the International Space Station. Image Credits: NASA's Goddard Space Flight Center.

"Neutron stars represent a natural density limit for stable matter that you can't exceed without becoming a black hole," said Goddard's Zaven Arzoumanian, NICER deputy principal investigator and science lead. "We don't know what happens to matter near this maximum density."

In order to study this limit, NICER will observe rapidly rotating neutron stars, also known as pulsars. These stars can rotate hundreds of times per second, faster than the blades of a household blender. Pulsars also possess enormously strong magnetic fields, trillions of times stronger than Earth's. The combination of fast rotation and strong magnetism accelerates particles to nearly the speed of light. Some of these particles follow the magnetic field to the surface, raining down on the magnetic poles and heating them until they form so-called hot spots that glow brightly in X-ray light.

"NICER is designed to see the X-ray emission from those hot spots," Arzoumanian said. "As the spots sweep toward us, we see more intensity as they move into our sightline and less as they move out, brightening and dimming hundreds of times each second."

A neutron star's gravity is so strong it warps space-time, the fabric of the cosmos, distorting our view of the star's surface and its sweeping hot spots. NICER will measure brightness changes related to these distortions as the star spins. This will allow scientists to determine the pulsar's radius, a key measurement needed to fully understand its interior structure.

"Once we have a measure of the mass and radius, we can tie those results directly into the nuclear physics of what goes on when you compress so much mass into such a small volume," Arzoumanian said.


Animation above: Animation of the NICER payload aboard the International Space Station. Animation Credits: NASA's Goddard Space Flight Center.

In addition to understanding how neutron stars are put together, NICER's observations will also help scientists better understand the critical mass a star must achieve before it can turn into a black hole. This is particularly important in systems where neutron stars orbit another star, allowing them to pull material off the companion star and gain more mass.

"The more neutron stars we observe at high masses, the higher the mass threshold becomes for a star turning into a black hole," said NICER science team member Alice Harding at Goddard. "Understanding what that critical mass is will help us determine how many black holes and neutron stars there are in the universe."

NICER will also provide scientists and technologists with a unique opportunity to make advances in deep space navigation. Its X-ray measurements will record the arrival times of pulses from each neutron star it observes, using the regular emissions of pulsars as ultra-precise cosmic clocks, rivaling the accuracy of atomic clocks such as those used inside GPS satellites. Built-in flight software — developed for the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) demonstration — can see how the predicted arrival of X-ray pulses from a given neutron star changes as NICER moves in its orbit. The difference between expected and actual arrival times allows SEXTANT to determine NICER's orbit solely by observing pulsars.

Although spacecraft in Earth orbit use the same GPS system that helps drivers navigate on the ground, there's no equivalent system available for spacecraft traveling far beyond Earth.

"Unlike GPS satellites, which just orbit around Earth, pulsars are distributed across our galaxy," said Jason Mitchell, the SEXTANT project manager at Goddard. "So we can use them to form a GPS-like system that can support spacecraft navigation throughout the solar system, enabling deep-space exploration in the future."

Installation on the space station provides scientists and technologists with an opportunity to develop a multi-purpose mission on an established platform.

"With the NICER-SEXTANT mission, we have an excellent opportunity to use the International Space Station to demonstrate technology that will lead us into the outer solar system and beyond, and tell us about some of the most exciting objects in the sky," Gendreau said.

NICER is an Astrophysics Mission of Opportunity within NASA's Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA's Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation.

Related Links:

NASA's NICER mission website: https://www.nasa.gov/nicer

More information on SEXTANT: https://gameon.nasa.gov/projects/deep-space-x-ray-navigation-and-communication/

Download NICER-SEXTANT multimedia resources: https://svs.gsfc.nasa.gov/Gallery/NICER.html

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

NASA's Goddard Space Flight Center, by Claire Saravia/Rob Garner.

Camera on NASA’s Lunar Orbiter Survived 2014 Meteoroid Hit












NASA - Lunar Reconnaissance Orbiter (LRO) patch.

May 26, 2017

On Oct.13, 2014 something very strange happened to the camera aboard NASA’s Lunar Reconnaissance Orbiter (LRO). The Lunar Reconnaissance Orbiter Camera (LROC), which normally produces beautifully clear images of the lunar surface, produced an image that was wild and jittery. From the sudden and jagged pattern apparent in the image, the LROC team determined that the camera must have been hit by a tiny meteoroid, a small natural object in space. 


Image above: The first wild back-and-forth line records the moment on October 13, 2014 when the left Narrow Angle Camera's radiator was struck by a meteoroid. Image Credits: NASA's Goddard Space Flight Center/Arizona State University.

LROC is a system of three cameras mounted on the LRO spacecraft. Two Narrow Angle Cameras (NACs) capture high resolution black and white images. The third Wide Angle Camera captures moderate resolution images using filters to provide information about the properties and color of the lunar surface.

The NAC works by building an image one line at a time. The first line is captured, then the orbit of the spacecraft moves the camera relative to the surface, and then the next line is captured, and so on, as thousands of lines are compiled into a full image.

According to Mark Robinson, professor and principal investigator of LROC at ASU’s School of Earth and Space Exploration, the jittery appearance of the image captured is the result of a sudden and extreme cross-track oscillation of the camera. LROC researchers concluded that there must have been a brief violent movement of the left Narrow Angle Camera.

There were no spacecraft events like solar panel movements or antenna tracking that might have caused spacecraft jitter during this period. “Even if there had been, the resulting jitter would have affected both cameras identically,” says Robinson. “The only logical explanation is that the NAC was hit by a meteoroid.”

How big was the meteoroid?

During LROC’s development, a detailed computer model was made to insure the NAC would not fail during the severe vibrations caused by the launch of the spacecraft. The computer model was tested before launch by attaching the NAC to a vibration table that simulated launch. The camera passed the test with flying colors, proving its stability.

Using this detailed computer model, the LROC team ran simulations to see if they could reproduce the distortions seen on the Oct. 13 image and determine the size of the meteoroid that hit the camera. They estimate the impacting meteoroid would have been about half the size of a pinhead (0.8 millimeter), assuming a velocity of about 4.3 miles (7 kilometers) per second and a density of an ordinary chondrite meteorite (2.7 grams/cm3).

“The meteoroid was traveling much faster than a speeding bullet,” says Robinson. “In this case, LROC did not dodge a speeding bullet, but rather survived a speeding bullet!”

How rare is it that the effects of an event like this were captured on camera? Very rare, according to Robinson. LROC typically only captures images during daylight and then only about 10 percent of the day, so for the camera to be hit by a meteor during the time that it was also capturing images is statistically unlikely.


Image above: The Narrow Angle Camera sits on a bench in the clean room at Malin Space Science Systems. The radiator (right) extends off the electronics end and keeps the sensor cool while imaging the moon. Computer modeling shows the meteoroid impacted somewhere on the radiator. Image Credits: Malin Space Science Systems/Arizona State University.

“LROC was struck and survived to keep exploring the moon,” says Robinson, “thanks to Malin Space Science Systems’ robust camera design.”

“Since the impact presented no technical problems for the health and safety of the instrument, the team is only now announcing this event as a fascinating example of how engineering data can be used, in ways not previously anticipated, to understand what is happing to the spacecraft over 236,000 miles (380,000 kilometers) from the Earth," said John Keller, LRO project scientist from NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Launched on June 18, 2008, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the moon.

Lunar Reconnaissance Orbiter or LRO. Image Credit: NASA

“A meteoroid impact on the LROC NAC reminds us that LRO is constantly exposed to the hazards of space,” says Noah Petro, deputy project scientist from NASA Goddard. “And as we continue to explore the moon, it reminds us of the precious nature of the data being returned.”

LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, as a project under NASA's Discovery Program. The Discovery Program is managed by NASA's Marshall Spaceflight Center in Huntsville, Alabama, for the Science Mission Directorate at NASA Headquarters in Washington.

The Lunar Reconnaissance Orbiter Camera was developed at Malin Space Science Systems in San Diego, California and Arizona State University in Tempe.

LRO (Lunar Reconnaissance Orbiter): http://www.nasa.gov/mission_pages/LRO/main/index.html and http://www.nasa.gov/lro

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center, by Nancy Neal Jones/Karl Hille.

Greetings, Orbiter.ch

CubeSats Deployed Before Upcoming Crew and Cargo Missions












ISS - Expedition 51 Mission patch.

May 26, 2017

More CubeSats were ejected from the International Space Station this week to explore the Earth’s upper atmosphere. Meanwhile, the Expedition 51 crew trained for a crew departure and cargo craft arrival.

NanoRacks, a private company with facilities on the space station, deployed a total of 17 CubeSats over two days this week from a satellite deployer outside the Japanese Kibo lab module. The tiny satellites will orbit Earth for up to two years observing Earth’s thermosphere and studying space weather.


Image above: A trio of CubeSats, with Earth’s limb and thin atmosphere in the background, is seen shortly after being ejected from a small satellite deployer outside Japan’s Kibo lab module. Image Credit: NASA.

Two Expedition 51 crew members are returning to Earth June 2 completing a 196 day mission in space. Soyuz Commander Oleg Novitskiy and Flight Engineer Thomas Pesquet practiced their descent today in their Soyuz MS-03 spacecraft. The duo are expected to land in Kazakhstan next Friday at 10:10 a.m. EDT.

The Dragon resupply ship, from SpaceX and loaded with brand new science experiments, will launch June 1 and arrive at the station June 4. NASA astronaut Jack Fischer will be at the robotics controls commanding the Canadarm2 to reach out and grapple Dragon. He and station Commander Peggy Whitson familiarized themselves today with the Dragon capture procedures and lighting conditions inside the cupola.

Related links:

CubeSats: https://www.nasa.gov/mission_pages/cubesats/index.html

NanoRacks: http://nanoracks.com/products/smallsat-deployment/

Soyuz MS-03: https://www.nasa.gov/feature/visiting-vehicle-launches-arrivals-and-departures

SpaceX: https://www.nasa.gov/spacex

Expedition 51: https://www.nasa.gov/mission_pages/station/expeditions/expedition51/index.html

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

Best regards, Orbiter.ch

NASA’s SDO Sees Partial Eclipse in Space












NASA - Solar Dynamics Observatory (SDO) patch.

May 26, 2017

On May 25, 2017, NASA's Solar Dynamics Observatory, or SDO, saw a partial solar eclipse in space when it caught the moon passing in front of the sun. The lunar transit lasted almost an hour, between 2:24 and 3:17 p.m. EDT, with the moon covering about 89 percent of the sun at the peak of its journey across the sun’s face. The moon’s crisp horizon can be seen from this view because the moon has no atmosphere to distort the sunlight.

While the moon’s edge appears smooth in these images, it’s actually quite uneven. The surface of the moon is rugged, sprinkled with craters, valleys and mountains. Peer closely at the image, and you may notice the subtle, bumpy outline of these topographical features.


Animation above: On May 25, 2017, NASA’s Solar Dynamics Observatory, or SDO, experienced a partial solar eclipse in space when it observed the moon passing in front of the sun. The lunar transit lasted about an hour, between 2:24 and 3:17 p.m. EDT, with the moon covering about 89 percent of the sun at the peak of its journey across the face of the sun. Animation Credits: NASA’s Goddard Space Flight Center/SDO/Joy Ng, producer.

Later this summer on Aug. 21, 2017, SDO will witness another lunar transit, but the moon will only barely hide part of the sun. However, on the same day, a total eclipse will be observable from the ground. A total solar eclipse — in which the moon completely obscures the sun — will cross the United States on a 70-mile-wide ribbon of land stretching from Oregon to South Carolina. Throughout the rest of North America — and even in parts of South America, Africa, Europe and Asia — a partial eclipse will be visible.

The moon’s rough, craggy terrain influences what we see on Earth during a total solar eclipse. Light rays stream through lunar valleys along the moon’s horizon and form Baily’s beads, bright points of light that signal the beginning and end of totality.

The moon’s surface also shapes the shadow, called the umbra, that races across the path of totality: Sunlight peeks through valleys and around mountains, adding edges to the umbra. These edges warp even more as they pass over Earth’s own mountain ranges. Visualizers used data from NASA’s Lunar Reconnaissance Orbiter, or LRO, coupled with NASA topographical data of Earth, to precisely map the upcoming eclipse in unprecedented detail. This work shows the umbral shape varies with time, and is not simply an ellipse, but an irregular polygon with slightly curved edges.

LRO is currently at the moon gathering data and revolutionizing our understanding of Earth’s nearest celestial neighbor. Knowing the shape of Earth and the moon plays a big part in accurately predicting the umbra’s shape as it falls on Earth, come Aug. 21.

SDO will see its partial eclipse in space just after the total eclipse exits the United States.

For more information about the upcoming total solar eclipse, visit eclipse2017.nasa.gov.

Related links:

NASA Satellites Ready When Stars and Planets Align: https://www.nasa.gov/feature/goddard/2017/nasa-satellites-ready-when-stars-and-planets-align

SDO Witnesses a Double Eclipse: http://orbiterchspacenews.blogspot.ch/2016/09/nasas-sdo-witnesses-double-eclipse.html

The Moon and Sun: Two NASA Missions Join Images: https://www.nasa.gov/mission_pages/LRO/news/sun-moon.html

NASA's Solar Dynamics Observatory, or SDO: https://www.nasa.gov/mission_pages/sdo/main/index.html

NASA’s Lunar Reconnaissance Orbiter, or LRO: https://www.nasa.gov/mission_pages/LRO/overview/index.html

Animation (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, By Lina Tran/Rob Garner.


Greetings, Orbiter.ch

Soyuz rocket successfully lift off EKS-2












ROSCOSMOS logo.

May 26, 2017


Image above: Launch of the Soyuz-2.1b rocket with the EKS-2 satellite from the Plesetsk Cosmodrome on May 25, 2017. Image Credit: Russian Ministry of Defence.

Shortly after 2:34 a.m. EDT (06:34 GMT), May 25, 2017, a Russian Soyuz 2.1b rocket lifted off from site No. 43 at the Plesetsk Cosmodrome and delivered the second of the EKS series of early-warning satellites to a rare Tundra orbit.

Soyuz 2.1b launches Kosmos-2518 (EKS-2)

A Russian government Soyuz rocket as launched the EKS 1 early warning satellite for the Russian military. The EKS, or Tundra, satellites fly in highly elliptical tundra orbits. The rocket fly in the Soyuz-2.1b configuration with a Fregat upper stage.


Image above: A small-scale model of the EKS series of early-warning satellites. Image credit: The Moscow Times.

The Fregat-MT, outfitted with an S5.95 engine, provided up to 4,460 pounds-force (about 20 kilonewtons) of vacuum thrust over multiple firings to deliver the EKS-2 satellite to its drop-off spot. EKS-2, which has its own propulsion system, will fine-tune its orbit over the coming days to place itself in its desired Tundra orbit.

For more Information about ROSCOSMOS, visit: https://www.roscosmos.ru/

Images (mentioned), Video (SciNews), Text, Credits: ROSCOSMOS/Orbiter.ch Aerospace.

Greetings, Orbiter.ch

jeudi 25 mai 2017

New Horizons Deploys Global Team for Rare Look at Next Flyby Target















NASA - New Horizons Mission logo / NASA & DLR - SOFIA patch.

May 25, 2017


Image above: Artist's view of New Horizons spacecraft flyby 2014 MU69 Kuiper Belt object. Image Credit: NASA.

On New Year’s Day 2019, more than 4 billion miles from home, NASA’s New Horizons spacecraft will race past a small Kuiper Belt object known as 2014 MU69 – making this rocky remnant of planetary formation the farthest object ever encountered by any spacecraft.

But over the next six weeks, the New Horizons mission team gets an “MU69” preview of sorts – and a chance to gather some critical encounter-planning information – with a rare look at their target object from Earth.


Image above: First look: Projected path of the 2014 MU69 occultation shadow, across South America and the southern tip of Africa, on June 3. Image Credits: NASA/JHUAPL/SWRI.

On June 3, and then again on July 10 and July 17, MU69 will occult – or block the light from – three different stars, one on each date. To observe the June 3 “stellar occultation,” more than 50 team members and collaborators are deploying along projected viewing paths in Argentina and South Africa. They’ll fix camera-equipped portable telescopes on the occultation star and watch for changes in its light that can tell them much about MU69 itself.

“Our primary objective is to determine if there are hazards near MU69 – rings, dust or even satellites – that could affect our flight planning,” said New Horizons Principal Investigator Alan Stern, of Southwest Research Institute (SwRI) in Boulder, Colorado. “But we also expect to learn more about its orbit and possibly determine its size and shape. All of that will help feed our flyby planning effort.”

What Are They Looking at?

In simplest terms, an astronomical occultation is when something moves in front of, or occults, something else. “When the moon passes in front of the sun and we have a solar eclipse, that's one kind of occultation,” said Joel Parker, a New Horizons co-investigator from SwRI. “If you're in the path of an eclipse, it means you're in the path of the shadow on Earth that’s created by the moon passing between us and the sun. If you're standing in the right place at the right time, the solar eclipse can last up to a few minutes.”


Animation above: New Horizons Flyby the Pluto System. Animation Credit: NASA.

The team will have no such luxury with the MU69 occultations. Marc Buie, the New Horizons co-investigator from SwRI who is leading the occultation observations, said that because MU69 is so small – thought to be about 25 miles (40 kilometers) across – the occultations should only last about two seconds.  But scientists can learn a lot from even that, and observations from several telescopes that see different parts of the shadow can reveal information about an object’s shape as well as its brightness.

A Space Challenge

The mission team has 22 new, portable 16-inch (40-centimeter) telescopes at the ready, along with three others portables and over two-dozen fixed-base telescopes that will be located along the occultation path through Argentina and South Africa. But deciding exactly where to place them was a challenge. This particular Kuiper Belt object was discovered just three years ago, so its orbit is still largely unknown. Without a precise fix on the object’s position – or on the exact path its narrow shadow might take across Earth – the team is spacing the telescope teams along “picket fence lines,” one every 6 to 18 miles (10 or 25 kilometers), to increase the odds that at least one or more of the portable telescopes will catch the center of the event and help determine the size of MU69.

The other telescopes will provide multiple probes for debris that could be a danger to the fast-moving New Horizons spacecraft when it flies by MU69 at about 35,000 miles per hour (56,000 kilometers per hour), on Jan. 1, 2019.


Image above: New Horizons team members prepare one of the new 16-inch telescopes for deployment to occultation observation sites in Argentina and South Africa. Image Credits: Kerri Beisser.

“Deploying on two different continents also maximizes our chances of having good weather,” said New Horizons Deputy Project Scientist Cathy Olkin, from SwRI. “The shadow is predicted to go across both locations and we want observers at both, because we wouldn't want a huge storm system to come through and cloud us out — the event is too important and too fleeting to miss.”

The team gets help from above for the July 10 occultation, adding the powerful 100-inch (2.5-meter) telescope on NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA). Enlisting SOFIA, with its vantage point above the clouds, takes the bad weather factor out of the picture. The plane also should be able to improve its measurements by maneuvering into the very center of the occultation shadow.

Insight for Encounter Planning

Any information on MU69, gathered from the skies or on the ground, is welcome. Carly Howett, deputy principal investigator of New Horizons' Ralph instrument, of SwRI, said so little is known about MU69 that the team is planning observations of a target it doesn’t fully understand – and time to learn more about the object is short. “We were only able to start planning the MU69 encounter after we flew by Pluto in 2015,” she said.  “That gives us two years, instead of almost seven years we had to plan the Pluto encounter. So it's a very different and, in many ways, more challenging flyby to plan.”


Image above: NASA & DLR airborne Stratospheric Observatory for Infrared Astronomy (SOFIA) on NASA's Boeing 747 SP. Image Credit: NASA.

If weather cooperates and predicted targeting proves on track, the upcoming occultation observations could provide the first precise size and reflectivity measurements of MU69. These figures will be key to planning the flyby itself – knowing the size of the object and the reflectivity of its surface, for example, helps the team set exposure times on the spacecraft’s cameras and spectrometers.

“Spacecraft flybys are unforgiving,” Stern said. “There are no second chances. The upcoming occultations are valuable opportunity to learn something about MU69 before our encounter, and help us plan for a very unique flyby of a scientifically important relic of the solar system’s era of formation.”

Follow the observations in Argentina, South Africa and on board SOFIA on Facebook https://www.facebook.com/new.horizons1/ and Twitter https://twitter.com/NASANewHorizons

Related links:

NASA's New Horizons: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA): http://www.nasa.gov/mission_pages/SOFIA/index.html

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Bill Keeter.

Greetings, Orbiter.ch

Rocket Lab successfully makes it to space











Rocket Lab logo.

May 25, 2017

It's a Test - Launch Day Video

Video above: It's a Test - Rocket Lab's Electron launch test at 16:20pm Thursday 25 May (NZST). Video Credits: Rocket Lab/KiwiSpace Foundation.

Electron lifted-off at 16:20 NZST from Rocket Lab Launch Complex 1 on the Mahia Peninsula in New Zealand. It was the first orbital-class rocket launched from from a private launch site in the world.

“It has been an incredible day and I’m immensely proud of our talented team,” said Peter Beck, CEO and founder of Rocket Lab. “We’re one of a few companies to ever develop a rocket from scratch and we did it in under four years. We’ve worked tirelessly to get to this point. We’ve developed everything in house, built the world’s first private orbital launch range, and we’ve done it with a small team.

“It was a great flight. We had a great first stage burn, stage separation, second stage ignition and fairing separation. We didn’t quite reach orbit and we’ll be investigating why, however reaching space in our first test puts us in an incredibly strong position to accelerate the commercial phase of our programme, deliver our customers to orbit and make space open for business,” says Beck.


Image above: Rocket Lab broke new ground today when its Electron rocket reached space at 16:23 NZST. Image Credit: Rocket Lab.

Over the coming weeks, Rocket Lab’s engineers in Los Angeles and Auckland, New Zealand will work through the 25,000 data channels that were collected during. The results will inform measures taken to optimize the vehicle.

“We have learnt so much through this test launch and will learn even more in the weeks to come. We’re committed to making space accessible and this is a phenomenal milestone in that journey. The applications doing this will open up are endless. Known applications include improved weather reporting, Internet from space, natural disaster prediction, up-to-date maritime data as well as search and rescue services,” says Beck.

Today’s launch was the first of three test flights scheduled for this year. Rocket Lab will target getting to orbit on the second test and look to maximize the payload the rocket can carry.


Image above: Rocket Lab Electron rocket poster. Image Credit: Rocket Lab.

At full production, Rocket Lab expects to launch more than 50 times a year, and is regulated to launch up to 120 times a year. In comparison, there were 22 launches last year from the United States, and 82 internationally.

Rocket Lab’s commercial phase will see Electron fly already-signed customers including NASA, Spire, Planet, Moon Express and Spaceflight.

For more information about Rocket Lab, visit: https://www.rocketlabusa.com/

Images (mentioned),, Video (mentioned), Text, Credit: Rocket Lab.

Best regards, Orbiter.ch

Collapsing Star Gives Birth to a Black Hole














NASA - Hubble Space Telescope patch / NASA - Spitzer Space Telescope patch.

May 25, 2017

Astronomers have watched as a massive, dying star was likely reborn as a black hole. It took the combined power of the Large Binocular Telescope (LBT), and NASA's Hubble and Spitzer space telescopes to go looking for remnants of the vanquished star, only to find that it disappeared out of sight.

It went out with a whimper instead of a bang.

The star, which was 25 times as massive as our sun, should have exploded in a very bright supernova. Instead, it fizzled out—and then left behind a black hole.

Star Gives Birth to Possible Black Hole in Hubble and Spitzer Images

Video above: A team of astronomers at The Ohio State University watched a star disappear and possibly become a black hole. Instead of becoming a black hole through the expected process of a supernova, the black hole candidate formed through a "failed supernova." Video Credits: NASA’s Goddard Space Flight Center/Katrina Jackson.

"Massive fails" like this one in a nearby galaxy could explain why astronomers rarely see supernovae from the most massive stars, said Christopher Kochanek, professor of astronomy at The Ohio State University and the Ohio Eminent Scholar in Observational Cosmology.

As many as 30 percent of such stars, it seems, may quietly collapse into black holes — no supernova required.

"The typical view is that a star can form a black hole only after it goes supernova," Kochanek explained. "If a star can fall short of a supernova and still make a black hole, that would help to explain why we don’t see supernovae from the most massive stars."


Image above: This pair of visible-light and near-infrared Hubble Space Telescope photos shows the giant star N6946-BH1 before and after in vanished out of sight by imploding to form a black hole. The left image shows the 25 solar mass star as it looked in 2007. In 2009, the star shot up in brightness to become over 1 million times more luminous than our sun for several months. But then it seemed to vanish, as seen in the right panel image from 2015. A small amount of infrared light has been detected from where the star used to be. This radiation probably comes from debris falling onto a black hole. The black hole is located 22 million light-years away in the spiral galaxy NGC 6946. Image Credits: NASA, ESA, and C. Kochanek (OSU).

He leads a team of astronomers who published their latest results in the Monthly Notices of the Royal Astronomical Society.

Among the galaxies they've been watching is NGC 6946, a spiral galaxy 22 million light-years away that is nicknamed the "Fireworks Galaxy" because supernovae frequently happen there — indeed, SN 2017eaw, discovered on May 14th, is shining near maximum brightness now. Starting in 2009, one particular star, named N6946-BH1, began to brighten weakly. By 2015, it appeared to have winked out of existence.

After the LBT survey for failed supernovas turned up the star, astronomers aimed the Hubble and Spitzer space telescopes to see if it was still there but merely dimmed. They also used Spitzer to search for any infrared radiation emanating from the spot. That would have been a sign that the star was still present, but perhaps just hidden behind a dust cloud.


Image above: The doomed star, named N6946-BH1, was 25 times as massive as our sun. It began to brighten weakly in 2009. But, by 2015, it appeared to have winked out of existence. By a careful process of elimination, based on observations researchers eventually concluded that the star must have become a black hole. This may be the fate for extremely massive stars in the universe. Image Credits: NASA, ESA, and P. Jeffries (STScI).

All the tests came up negative. The star was no longer there. By a careful process of elimination, the researchers eventually concluded that the star must have become a black hole.

It's too early in the project to know for sure how often stars experience massive fails, but Scott Adams, a former Ohio State student who recently earned his doctorate doing this work, was able to make a preliminary estimate.

"N6946-BH1 is the only likely failed supernova that we found in the first seven years of our survey. During this period, six normal supernovae have occurred within the galaxies we've been monitoring, suggesting that 10 to 30 percent of massive stars die as failed supernovae," he said.

"This is just the fraction that would explain the very problem that motivated us to start the survey, that is, that there are fewer observed supernovae than should be occurring if all massive stars die that way."

Hubble Space Telescope. Animation Credits: NASA/ESA

To study co-author Krzysztof Stanek, the really interesting part of the discovery is the implications it holds for the origins of very massive black holes — the kind that the LIGO experiment detected via gravitational waves. (LIGO is the Laser Interferometer Gravitational-Wave Observatory.)

It doesn't necessarily make sense, said Stanek, professor of astronomy at Ohio State, that a massive star could undergo a supernova — a process which entails blowing off much of its outer layers — and still have enough mass left over to form a massive black hole on the scale of those that LIGO detected.

"I suspect it's much easier to make a very massive black hole if there is no supernova," he concluded.

Adams is now an astrophysicist at Caltech. Other co-authors were Ohio State doctoral student Jill Gerke and University of Oklahoma astronomer Xinyu Dai. Their research was supported by the National Science Foundation.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington, D.C. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

Spitzer Space Telescope. Animation Credits: NASA/JPL-Caltech

The Large Binocular Telescope is an international collaboration among institutions in the United Sates, Italy and Germany.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Related Links:

The science paper by S. Adams et al.: https://media.stsci.edu/preview/file/science_paper/file_attachment/238/adams_kochanek_bh_mnras_paper.pdf

NASA's Hubble Portal: http://www.nasa.gov/hubble

NASA's Spitzer Portal: http://www.nasa.gov/spitzer

Caltech's Spitzer Portal: http://www.spitzer.caltech.edu/

Ohio State University's Release: http://news.osu.edu/

Images (mentioned), Animations (mentioned), Video (mentioned), Text, Credits: NASA/Karl Hille/Space Telescope Science Institute/Ray Villard/JPL/Elizabeth Landau/Caltech, Pasadena/Scott Adams/Ohio State University/Pam Frost Gorder.

Best regards, Orbiter.ch

A Whole New Jupiter: First Science Results from NASA’s Juno Mission












NASA - JUNO Mission logo.

May 25, 2017

Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought.

“We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. "It was a long trip to get to Jupiter, but these first results already demonstrate it was well worth the journey.”

Juno launched on Aug. 5, 2011, entering Jupiter’s orbit on July 4, 2016. The findings from the first data-collection pass, which flew within about 2,600 miles (4,200 kilometers) of Jupiter's swirling cloud tops on Aug. 27, are being published this week in two papers in the journal Science, as well as 44 papers in Geophysical Research Letters.


Image above: This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles.

“We knew, going in, that Jupiter would throw us some curves,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

Among the findings that challenge assumptions are those provided by Juno’s imager, JunoCam. The images show both of Jupiter's poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together.

“We're puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn't look like the south pole,” said Bolton. “We're questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we're going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”

Another surprise comes from Juno’s Microwave Radiometer (MWR), which samples the thermal microwave radiation from Jupiter’s atmosphere, from the top of the ammonia clouds to deep within its atmosphere. The MWR data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures. The data suggest the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred miles or kilometers.

(Click on the image for enlarge)

Image above: This sequence of enhanced-color images shows how quickly the viewing geometry changes for NASA’s Juno spacecraft as it swoops by Jupiter. The images were obtained by JunoCam. Image Credits: NASA/SWRI/MSSS/Gerald Eichstädt/Seán Doran.

Prior to the Juno mission, it was known that Jupiter had the most intense magnetic field in the solar system. Measurements of the massive planet’s magnetosphere, from Juno’s magnetometer investigation (MAG), indicate that Jupiter’s magnetic field is even stronger than models expected, and more irregular in shape. MAG data indicates the magnetic field greatly exceeded expectations at 7.766 Gauss, about 10 times stronger than the strongest magnetic field found on Earth.

“Juno is giving us a view of the magnetic field close to Jupiter that we’ve never had before,” said Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA's Goddard Space Flight Center in Greenbelt, Maryland. “Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”

Juno also is designed to study the polar magnetosphere and the origin of Jupiter's powerful auroras—its northern and southern lights. These auroral emissions are caused by particles that pick up energy, slamming into atmospheric molecules. Juno’s initial observations indicate that the process seems to work differently at Jupiter than at Earth.

Juno is in a polar orbit around Jupiter, and the majority of each orbit is spent well away from the gas giant. But, once every 53 days, its trajectory approaches Jupiter from above its north pole, where it begins a two-hour transit (from pole to pole) flying north to south with its eight science instruments collecting data and its JunoCam public outreach camera snapping pictures. The download of six megabytes of data collected during the transit can take 1.5 days.


Animation above: Juno spacecraft swings close to Jupiter. Animation Credit: NASA.

“Every 53 days, we go screaming by Jupiter, get doused by a fire hose of Jovian science, and there is always something new,” said Bolton. “On our next flyby on July 11, we will fly directly over one of the most iconic features in the entire solar system -- one that every school kid knows -- Jupiter’s Great Red Spot. If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno and her cloud-piercing science instruments.”

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the Juno mission for NASA. The principal investigator is Scott Bolton of the Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems, in Denver, built the spacecraft.

More information on the Juno mission is available at:

https://www.nasa.gov/juno

http://missionjuno.org

Follow the mission on Facebook and Twitter at:

http://www.facebook.com/NASAJuno

http://www.twitter.com/NASAJuno

Images (menrioned), Animation (mentioned), Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/Karen Northon/JPL/DC Agle/Southwest Research Institute/Deb Schmid.

Greetings, Orbiter.ch

mercredi 24 mai 2017

Cassini Looks on as Solstice Arrives at Saturn












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

May 24, 2017

NASA's Cassini spacecraft still has a few months to go before it completes its mission in September, but the veteran Saturn explorer reaches a new milestone today. Saturn's solstice -- that is, the longest day of summer in the northern hemisphere and the shortest day of winter in the southern hemisphere -- arrives today for the planet and its moons. The Saturnian solstice occurs about every 15 Earth years as the planet and its entourage slowly orbit the sun, with the north and south hemispheres alternating their roles as the summer and winter poles.


Animations above: These natural color views from Cassini show how the color of Saturn’s north-polar region changed between June 2013 and April 2017, as the northern hemisphere headed toward summer solstice. Animations Credits: NASA/JPL-Caltech/SSI/Hampton Univ.

Reaching the solstice, and observing seasonal changes in the Saturn system along the way, was a primary goal of Cassini's Solstice Mission -- the name of Cassini's second extended mission.

Cassini arrived at Saturn in 2004 for its four-year primary mission to study Saturn and its rings and moons. Cassini's first extended mission, from 2008 to 2010, was known as the Equinox Mission. During that phase of the mission, Cassini watched as sunlight struck Saturn's rings edge-on, casting shadows that revealed dramatic new ring structures. NASA chose to grant the spacecraft an additional seven-year tour, the Solstice Mission, which began in 2010.

"During Cassini's Solstice Mission, we have witnessed -- up close for the first time -- an entire season at Saturn," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. "The Saturn system undergoes dramatic transitions from winter to summer, and thanks to Cassini, we had a ringside seat."

Saturn

During its Solstice Mission, Cassini watched a giant storm erupt and encircle the planet. The spacecraft also saw the disappearance of bluer hues that had lingered in the far north as springtime hazes began to form there. The hazes are part of the reason why features in Saturn's atmosphere are more muted in their appearance than those on Jupiter.


Image above: Cassini's view of Saturn during its 2009 equinox shows both the northern and southern hemispheres equally sunlit, with the north pole half in shadow. Since then, the sun has risen fully over the north, while the south has slipped into winter shadow. Image Credits: NASA/JPL/Space Science Institute.

Data from the mission showed how the formation of Saturn's hazes is related to the seasonally changing temperatures and chemical composition of Saturn's upper atmosphere. Cassini researchers have found that some of the trace hydrocarbon compounds there -- gases like ethane, propane and acetylene -- react more quickly than others to the changing amount of sunlight over the course of Saturn's year.

Researchers were also surprised that the changes Cassini observed on Saturn didn't occur gradually. They saw changes occur suddenly, at specific latitudes in Saturn's banded atmosphere. "Eventually a whole hemisphere undergoes change, but it gets there by these jumps at specific latitude bands at different times in the season," said Robert West, a Cassini imaging team member at JPL.

Rings

Following equinox and continuing toward northern summer solstice, the sun rose ever higher above the rings' northern face. And as the sun rises higher, its light penetrates deeper into the rings, heating them to the warmest temperatures seen there during the mission. The solstice sunlight helps reveal to Cassini's instruments how particles clump together and whether the particles buried in the middle of the ring plane have a different composition or structure than the ones in the rings' outer layers.


Image above: During its seven-year Solstice Mission, Cassini watched as a huge storm erupted and encircled Saturn. Scientists think storms like this are related, in part, to seasonal effects of sunlight on Saturn's atmosphere. Image Credits: NASA/JPL/Space Science Institute.

Saturn's changing angle with respect to the sun also means the rings are tipped toward Earth by their maximum amount at solstice. In this geometry, Cassini's radio signal passes more easily and cleanly through the densest rings, providing even higher-quality data about the ring particles there.

Titan

Cassini has watched Saturn's largest moon, Titan, change with the seasons, with occasional dramatic outbursts of cloud activity. After observing methane storm clouds around Titan's south pole in 2004, Cassini watched giant storms transition to Titan's equator in 2010. Although a few northern clouds have begun to appear, scientists have since been surprised at how long it has taken for cloud activity to shift to the northern hemisphere, defying climate models that had predicted such activity should have started several years earlier.


Image above: Following Saturnian equinox in 2009, Cassini observed cloud activity on Titan shift from southern latitudes toward the equator, and eventually to the high north. Such observations have provided evidence of seasonal shifts in Titan's weather systems. Image Credits: NASA/JPL/Space Science Institute.

"Observations of how the locations of cloud activity change and how long such changes take give us important information about the workings of Titan's atmosphere and also its surface, as rainfall and wind patterns change with the seasons too," said Elizabeth Turtle, a Cassini imaging team associate at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

In 2013, Cassini observed a sudden and rapid buildup of haze and trace hydrocarbons in the south that were previously observed only in Titan's high north. This indicated to scientists that a seasonal reversal was underway, in which Titan’s main atmospheric circulation changes direction. This circulation was apparently channeling fresh hydrocarbon chemicals from closer to the equator toward the south pole, where they were safe from destruction by sunlight as that pole moved deeper into winter shadow.

Enceladus

For Enceladus, the most important seasonal change was the onset of winter darkness in the south. Although it meant Cassini could no longer take sunlit images of the geologically active surface, the spacecraft could more clearly observe the heat coming from within Enceladus itself.


Image above: Saturn's Moon Enceladus. Image Credits: NASA/JPL/Space Science Institute.

With the icy moon's south pole in shadow, Cassini scientists have been able to monitor the temperature of the terrain there without concern for the sun's influence. These observations are helping researchers to better understand the global ocean that lies beneath the surface. From the moon's south polar region, that hidden ocean sprays a towering plume of ice and vapor into space that Cassini has directly sampled.

Toward the Final Milestone

As Saturn's solstice arrives, Cassini is currently in the final phase of its long mission, called its Grand Finale. Over the course of 22 weeks from April 26 to Sept. 15, the spacecraft is making a series of dramatic dives between the planet and its icy rings. The mission is returning new insights about the interior of the planet and the origins of the rings, along with images from closer to Saturn than ever before. The mission will end with a final plunge into Saturn's atmosphere on Sept. 15.

Cassini Spacecraft Animation. Video Credit: ESA

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 Cassini:

https://www.nasa.gov/cassini

https://saturn.jpl.nasa.gov

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

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

Best regards, Orbiter.ch

NASA Moves Up Launch of Psyche Mission to a Metal Asteroid












NASA - Psyche Mission logo.

May 24, 2017

Psyche, NASA's Discovery Mission to a unique metal asteroid, has been moved up one year with launch in the summer of 2022, and with a planned arrival at the main belt asteroid in 2026 -- four years earlier than the original timeline. 

“We challenged the mission design team to explore if an earlier launch date could provide a more efficient trajectory to the asteroid Psyche, and they came through in a big way,” said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. “This will enable us to fulfill our science objectives sooner and at a reduced cost.”

The Discovery program announcement of opportunity had directed teams to propose missions for launch in either 2021 or 2023. The Lucy mission was selected for the first launch opportunity in 2021, and Psyche was to follow in 2023.  Shortly after selection in January, NASA gave the direction to the Psyche team to research earlier opportunities.

"The biggest advantage is the excellent trajectory, which gets us there about twice as fast and is more cost effective," said Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. "We are all extremely excited that NASA was able to accommodate this earlier launch date. The world will see this amazing metal world so much sooner."

The revised trajectory is more efficient, as it eliminates the need for an Earth gravity assist, which ultimately shortens the cruise time. In addition, the new trajectory stays farther from the sun, reducing the amount of heat protection needed for the spacecraft. The trajectory will still include a Mars gravity assist in 2023.


Image above: Artist's Concept of Psyche Spacecraft with Five-Panel Array. Image Credits: NASA/JPL-Caltech/Arizona State Univ./Space Systems Loral/Peter Rubin.

"The change in plans is a great boost for the team and the mission," said Psyche Project Manager Henry Stone at NASA's Jet Propulsion Laboratory, Pasadena, California. "Our mission design team did a fantastic job coming up with this ideal launch opportunity."

The Psyche spacecraft is being built by Space Systems Loral (SSL), Palo Alto, California. In order to support the new mission trajectory, SSL redesigned the solar array system from a four-panel array in a straight row on either side of the spacecraft to a more powerful five-panel x-shaped design, commonly used for missions requiring more capability. Much like a sports car, by combining a relatively small spacecraft body with a very high-power solar array design, the Psyche spacecraft will speed to its destination at a faster pace than is typical for a larger spacecraft.

"By increasing the size of the solar arrays, the spacecraft will have the power it needs to support the higher velocity requirements of the updated mission," said SSL Psyche Program Manager Steve Scott.

The Psyche Mission

Psyche, an asteroid orbiting the sun between Mars and Jupiter, is made almost entirely of nickel-iron metal. As such, it offers a unique look into the violent collisions that created Earth and the terrestrial planets.

The Psyche Mission was selected for flight earlier this year under NASA's Discovery Program, a series of lower-cost, highly focused robotic space missions that are exploring the solar system.

The scientific goals of the Psyche mission are to understand the building blocks of planet formation and explore firsthand a wholly new and unexplored type of world. The mission team seeks to determine whether Psyche is the core of an early planet, how old it is, whether it formed in similar ways to Earth's core, and what its surface is like. The spacecraft's instrument payload will include magnetometers, multispectral imagers, and a gamma ray and neutron spectrometer.

For more information about NASA’s Psyche mission go to: http://www.nasa.gov/psyche

Image (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/Martin Perez/JPL/D.C. Agle/Arizona State University School of Earth and Space Exploration/Karin Valentine.

Greetings, Orbiter.ch

NASA’s CYGNSS Satellite Constellation Begins Public Data Release

NASA - Cyclone Global Navigation Satellite System (CYGNSS) logo.

May 24, 2017

On May 22, NASA’s Cyclone Global Navigation Satellite System (CYGNSS) began regular production of its science data products – measurements of ocean surface wind speed and roughness – with public release of these data facilitated by the NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC). The production and distribution is timed to coincide with the beginning of the Atlantic hurricane season on June 1.

CYGNSS – a constellation of eight microsatellite spacecraft launched into low inclination, low-Earth orbit over the tropics on December 15 – will make frequent measurements of ocean surface winds in the tropics, with a primary objective of monitoring the location, intensity, size, and development of tropical cyclones.


Image above: These maps show measurements of ocean surface wind speeds made by four of the eight CYGNSS spacecraft on March 6, 2017, as Tropical Cyclone Enawo approaches landfall on Madagascar. The times of the measurements are, from top to bottom: 1830, 1930, and 2030 UTC (1:30 p.m., 2:30 p.m., and 3:30 p.m. EST).

The ability of the CYGNSS constellation to track the development of surface winds in a major storm is demonstrated by preliminary measurements made during its flyover of Tropical Cyclone Enawo on March 6, as the system approached Madagascar with surface winds in excess of 100 mph.

“Successive spacecraft in the constellation observed Enawo over a period of several hours just before it made landfall on Madagascar,” explained Chris Ruf, Professor of Atmospheric Science at the University of Michigan and CYGNSS Principal Investigator. “During the flyover, four of our eight spacecraft were operating in science mode and we managed to capture important elements of the size and structure of the storm.” According to Ruf, the other four spacecraft were still undergoing engineering commissioning activities. “Those activities are now largely complete and, as we enter the Atlantic hurricane season, we expect to have all eight of them available for science observations. This will effectively double our sampling and coverage.” 

CYGNSS (Cyclone Global Navigation Satellite System) spacecraft

The CYGNSS mission is led by the University of Michigan. The Southwest Research Institute led the engineering development and manages the operation of the constellation. The University of Michigan Climate and Space Sciences and Engineering department leads the science investigation, and the Earth Science Division of NASA’s Science Mission Directorate oversees the mission.

Related link:

NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC): https://podaac.jpl.nasa.gov/

For more information about  CYGNSS (Cyclone Global Navigation Satellite System), visit: http://www.nasa.gov/cygnss/

Images, Text, Credits: NASA/Joe Atkinson.

Greetings, Orbiter.ch

Sentinel-2 captures coral bleaching of Great Barrier Reef










ESA - Sentinel-2 Mission logo.

24 May 2017

Sentinel-2

Scientists observed the bleaching of Australia’s Great Barrier Reef early this year using satellite images. While capturing these events from space has been difficult in the past, Sentinel-2’s frequent revisits and its resolution makes it possible.

The corals of the Great Barrier Reef have now suffered two bleaching events in successive years. Experts are very concerned about the capacity for reef survival under the increased frequency of these global warming-induced events.

Bleaching happens when algae living in the corals’ tissues, which capture the Sun’s energy and are essential to coral survival, are expelled owing to high water temperatures.

Sentinel-2 captures coral bleaching

The whitening coral may die, with subsequent effects on the reef ecosystem, and thus fisheries, regional tourism and coastal protection.

The bleached state of a coral can last up to six weeks. The corals might recover, or die and become covered by algae, in either case turning dark again, making them hard to distinguish from healthy coral in a satellite image. Such a pattern requires systematic and frequent monitoring to reliably identify a coral bleaching event from space.

Studying Sentinel-2 images captured over the reef between January and April, scientists working under ESA’s Sen2Coral project noticed areas that were likely to be coral appearing to turn bright white, then darken as time went on.

The event was confirmed by two successive images captured in February, indicating the approximate duration of the bleaching being at least 10 days.

“In general, interpreting changes is ambiguous. You can’t just jump to the conclusion brightening is bleaching because the brightness of any spot on a reef varies from image to image for many reasons due to both the water and bottom changes,” said Dr John Hedley, scientific leader of Sen2Coral.

Sentinel-2 times series over corals

Dr Chris Roelfsema of the University of Queensland’s Remote Sensing Research Centre, and lead of the Great Barrier Reef Habitat Mapping Project, conducted field campaigns in the area, collecting thousands of geo-located photos of the corals in January and again in April. These were used to confirm the satellite observations.

“Sadly, in the areas where bleaching can be seen, the abundant coral cover we observed in January was in April mostly overgrown with turf algae, with only some individual coral species surviving. The imagery and field data suggest this area has been hit badly,” he said.

Since monitoring of bleaching is typically conducted manually by airborne surveys or diving, many reefs of the world are not effectively monitored.

Bleaching is also difficult to monitor in satellite imagery because of constant variations in the overlying water and other changes in the bottom such as micro-algal blooms.

The frequent revisits of Sentinel-2 allow these variations to be removed and help the detection of bleaching events before coral recovery or algal overgrowth turns the area dark again.

Field campaign results

With both Sentinel-2 satellites now in orbit, the mission can contribute significantly to an increased understanding of pressures on coral reefs at a global scale.

“Sentinel 2 is a game-changer for coral reef remote sensing; the combination of frequent revisit and spatial resolution is enabling us to see genuinely new things,” said Dr Hedley.

“We now know bleaching can be visible in satellite imagery, but the challenge is to produce reliable software that can map or quantify that.

“It has to account for all sources of temporal variation and, importantly, the uncertainty in the methods. The methods have to be open for scientists to be able to interpret the outputs.”

Towards this aim, a set of software specifically for coral reef applications is being created by ESA’s Sen2Coral project and is expected to be available on the open-source SNAP toolbox by the end of the year.

Related links:

SNAP toolbox: http://step.esa.int/main/toolboxes/snap

Sen2Coral: http://www.sen2coral.org/

Remote Sensing Research Centre: https://www.rsrc.org.au/gbrcommon

Sentinel-2: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-2

Images, Video, Text, Credits: ESA/contains modified Copernicus Sentinel data (2016–17), processed by J. Hedley; conceptual model by C. Roelfsema/C. Roelfsema, University of Queensland.

Greetings, Orbiter.ch