vendredi 16 novembre 2018

Russia’s Cargo Craft Blasts Off to Station for Sunday Delivery












ROSCOSMOS - Russian Vehicles patch.

November 16, 2018


Image above: Russia’s Progress 71 cargo craft blasts off on time to the International Space Station for a Sunday delivery. Image Credits: ROSCOSMOS/NASA.

Carrying almost three tons of food, fuel and supplies for the International Space Station crew, the unpiloted Russian Progress 71 cargo spacecraft launched at 1:14 p.m. EST (12:14 a.m. Saturday, Nov. 17, Baikonur) from the Baikonur Cosmodrome in Kazakhstan.

At the time of launch, the International Space Station was flying about 252 statute miles over southern Kazakhstan.

The resupply ship reached preliminary orbit and deployed its solar arrays and navigational antennas as planned. The Russian cargo craft will make 34 orbits of Earth before docking to the orbiting laboratory at 2:30 p.m. on Sunday, Nov. 18. NASA Television coverage of rendezvous and docking will begin at 1:45 p.m.

Soyuz-FG launches Progress MS-10

Progress 71 will remain docked at the station for more than four months before departing in March for its deorbit in Earth’s atmosphere.

Crew aboard the space station are scheduled to receive two cargo resupply missions in the coming days. Tomorrow, launch of Northrop Grumman’s Antares rocket with Cygnus cargo spacecraft bound for the International Space Station is targeted for 4:01 a.m. from Pad 0A of Virginia Space’s Mid-Atlantic Regional Spaceport, located at NASA’s Wallops Flight Facility on Virginia’s Eastern Shore. NASA TV will provide launch broadcast coverage online beginning at 3:30 a.m. A Cygnus launch Saturday would result in capture and berthing on Monday, Nov. 19.

Related links:

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

NASA TV: http://www.nasa.gov/live

ROSCOSMOS Press Release: https://www.roscosmos.ru/25739/

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

Image (mentioned), Video, Text, Credits: NASA/Marck Garcia/SciNews.

Best regards, Orbiter.ch

Io Rising













NASA - JUNO Mission logo.

Nov. 16, 2018


Jupiter's moon Io rises just off the horizon of the gas giant planet in this image from NASA's Juno spacecraft. Slightly larger than Earth's moon, Io is the most volcanically active world in the solar system.

This color-enhanced image was taken at 2:26 p.m. PDT (5:56 p.m. EDT) on Oct. 29, 2018 as the spacecraft performed its 16th close flyby of Jupiter. At the time, Juno was about 11,400 miles (18,400 kilometers) from the planet's cloud tops, at approximately 32 degrees south latitude.

Citizen scientists Gerald Eichstädt and Justin Cowart created this image using data from the spacecraft's JunoCam imager. This image has been rotated approximately 155 degrees from the source image.

Juno spacecraft orbiting Jupiter

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.

Image, Animation, Text, Credits: NASA/Tony Greicius/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Justin Cowart.

Greetings, Orbiter.ch

Electric blue thrusters propelling BepiColombo to Mercury













ESA - BepiColombo Mission patch.

16 November 2018

In mid-December, twin discs will begin glowing blue on the underside of a minibus-sized spacecraft in deep space. At that moment Europe and Japan’s BepiColombo mission will have just come a crucial step closer to Mercury.

This week sees the in-flight commissioning and test firing of the four thrusters – with one or two firing at a time – of the Solar Electric Propulsion System that BepiColombo relies on to reach the innermost planet. This marks the first in-flight operation of the most powerful and highest-performance electric propulsion system flown on any space mission to date.

Twin ion thrusters firing

Each thruster and its associated power processing and propellant flow control units will be tested to full power to check no ill-effects were incurred from launch, culminating in the first twin thruster operations – the configuration to be used throughout most of the mission.

Their first routine firing is scheduled for the middle of next month, and the propulsion system will operate continuously for three months to optimise the spacecraft’s trajectory for the long voyage to Mercury.

The voyage inward

BepiColombo, launched from Europe’s Spaceport in French Guiana on 20 October, faces a different challenge from ESA planetary science missions before it: it is headed inward, toward the Sun, not out, and needs to lose velocity instead of gaining it.

Animation visualising BepiColombo’s journey to Mercury

Like all objects in the Solar System, the spacecraft is in solar orbit, moving perpendicular to the pull of the Sun’s gravity. BepiColombo therefore has to slow down through a series of braking manoeuvres and flybys, making it more susceptible to the Sun’s gravity and letting it spiral closer to the heart of the Solar System.

The thrust produced by the electric propulsion system serves to decelerate the spacecraft, or in some cases accelerates it to make its braking flybys more effective. No less than nine planetary flybys of Earth (once), Venus (twice) and Mercury itself (six times) are required to place the multi-module spacecraft in orbit around Mercury in seven years’ time.

Space tug

The Mercury Transfer Module portion of the spacecraft, containing the propulsion system, is in essence a high performance ‘space tug’. Its task is to perform all the active trajectory control manoeuvres needed to convey the other portions of the BepiColombo ‘stack’ – ESA’s Mercury Planet Orbiter and Japan’s Mercury Magnetospheric Orbiter – to Mercury orbit.

Thrusters firing on BepiColombo

The high performance of the propulsion system, in terms of the amount of fuel the thrusters require, is critical. Inert xenon gas is fed in to the thrusters, where electrons are first stripped off the xenon atoms. The resulting electrically charged atoms, referred to as ions, are then focused and ejected out of the thrusters using a high voltage grid system at a velocity of 50 000 meters per second.

This exhaust velocity is 15 times greater than conventional chemical rocket thrusters, allowing a dramatic reduction in the amount of propellant required to achieve the mission.

“The propulsion system transforms electricity generated by the Mercury Transfer Module’s twin 15 m-long solar arrays into thrust,” explains ESA electric propulsion engineer Neil Wallace.

MTM at base of BepiColombo

“At full power, a thrust equivalent to the weight of three 1-euro coins is developed, meaning that the thrusters have to keep firing for long periods to be effective, but in the absence of any drag and assuming you are patient, the manoeuvres that are possible and the payload that can be carried are dramatic.”

Electrifying spacecraft propulsion

The four T6 thrusters around which the solar electric propulsion system is designed, have a heritage dating back decades. QinetiQ in the UK – formerly the UK Defence Evaluation and Research Agency and before that the Farnborough Royal Aircraft Establishment – has been researching electric propulsion since the 1960s.

The first flight of their technology came with the 10 cm-diameter T5 thruster, a key element of ESA’s 2009 gravity-mapping GOCE mission, where it allowed the satellite to orbit at the top of Earth’s atmosphere for over three years, skimming through the diffuse atmosphere at the unprecedentedly low orbital altitude needed for the mission.

T6 test firing

The scaled-up T6 thrusters are 22 cm in diameter, the increase in size required for the higher thrust and lifetime requirements of the BepiColombo mission. And unlike GOCE’s T5, these T6 thrusters are manoeuverable, courtesy of gimbal systems developed by RUAG Space in Austria.

“They are clever mechanisms that complicate the system design a bit – all the electrical cables and pipes have to cross a moving boundary – but add a lot to performance,” adds Neil. “They ensure the thrust vector of either a single or double engine firing crosses through the centre of gravity of the spacecraft, which changes over time as propellant is used up.”

Thruster steering test

Thruster operations are controlled using two Power Processing Units, the architecture of which are designed to support the firing of two T6s simultaneously even in the event of any system anomaly, guaranteeing the maximum thrust of 250 mN can be maintained.

Injecting intelligence

“The intelligence of the system for autonomous thruster operation comes from these Power Processing Units – contributed by Airbus Crisa in Spain,” explains Neil, “which supply the regulated voltages and currents to the thrusters based on instructions from ground control via the spacecraft on-board computer.”

Propulsion system

The other key elements are propellant Flow Control Units, also overseen by the PPUs, and the high-voltage electrical harness. The FCUs ensure the correct flows of xenon gas are supplied to the thrusters and were developed by Bradford Engineering in the Netherlands to provide programmable flow rates.

The various elements of the propulsion system have undergone individual and extensive performance and qualification testing ultimately concluding in a series of tests performed at QinetiQ's Farnborough site.

Testing times

The spacecraft configuration and the extreme nature of the BepiColombo mission – needing to function in thermal conditions akin to placing it in a pizza oven – often demanded similarly extreme test scenarios, pushing the solar electric propulsion technology and test facilities to their limits.

“One important test early in the programme was to ensure that two thrusters could be operated in close proximity for prolonged periods without harmful interactions,” adds Neil. “They turned out to be remarkably tolerant of each other with no measureable effects.”

Test setup

One of the biggest ironies of the thruster qualification for BepiColombo, heading close to the Sun, was the extreme minimum temperatures experienced by its ion thrusters.

Neil explains: “Despite the fact the mission is headed to Mercury, the bulk of the spacecraft shadows the thrusters for very long periods and when not operating they naturally cool to temperatures way lower than ever tested in the past. We needed to prove they would turn-on and operate within specification when cooled to minus 150 C.

BepiColombo plasma simulation

“It was a remarkable testament to the robustness of the technology that even after temperatures sufficient to freeze the xenon in the pipes the thrusters were able to start and operate flawlessly.”

End of the journey

The propulsion system is dependent on the Mercury Planetary Orbiter’s onboard computer for its control and command, so by itself it will not be able to function. Its ultimate fate is to be cast off, when the three-module BepiColombo stack separates before entering Mercury orbit, to circle the Sun indefinitely in the vicinity of the planet, letting the two science modules go to work.

BepiColombo arrival at Mercury timeline

“At one point while planning the BepiColombo mission, the Mercury Transfer Module was planned to impact the planet,” Neil comments, “a sort of Viking funeral that seemed fitting to all of us engineers.”

Gridded ion thruster technology will have a life far beyond BepiColombo however, with commercial applications in development, and future, even more ambitious ESA science missions set to rely on the technology.

Related links:

ESA's BepiColombo: http://www.esa.int/Our_Activities/Space_Science/BepiColombo

T6 ion thrusters installed on BepiColombo: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Electric_blue_thrusters_propelling_BepiColombo_to_Mercury

Propulsion and Aerothermodynamics: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Propulsion_and_Aerothermodynamics

Propulsion Laboratory: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Propulsion_Laboratory

QinetiQ Space: http://www.qinetiq.be/

Images, Videos, Text, Credits: ESA/Félicien Filleul/QinetiQ/ATG medialab/ESA/D.Tagliafierro (TAS-I)/CC BY-SA 3.0 IGO.

Best regards, Orbiter.ch

jeudi 15 novembre 2018

SpaceX - Es'hail-2 Mission Success













SpaceX - Falcon 9 / Es'hail-2 Mission patch.

Nov. 15, 2018

SpaceX Falcon 9 Es'hail-2 lift off

SpaceX successfully launched the Es’hail-2 satellite on Thursday, November 15 from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida. Liftoff occurred at 3:46 p.m. EST, or 20:46 UTC, and the satellite was deployed to a geostationary transfer orbit (GTO) about 32 minutes after liftoff.

Es’hail-2 Mission

Falcon 9’s first stage for the Es’hail-2 mission previously supported the Telstar 19 VANTAGE mission in July 2018. Following stage separation, SpaceX landed Falcon 9’s first stage on the “Of Course I Still Love You” droneship, which was stationed in the Atlantic Ocean.

Falcon 9 first stage after landing on Droneship "Of Course I Still Love You"

Es’hail 2 communications satellite. Built by Mitsubishi Electric Corp. and owned by Qatar’s national satellite communications company Es’hailSat, Es’hail 2 will provide television broadcasts, broadband connectivity and government services to Qatar and neighboring parts of the Middle East, North Africa and Europe.

Es’hail 2 communications satellite

Es’hail 2 also carries the first amateur radio payload to fly in geostationary orbit.

For more information about SpaceX, visit: https://www.spacex.com/

Images, Video, Text, Credits: SpaceX/Mitsubishi Electric Corp./Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Huge impact crater found under Greenland Hiawatha glacier













NASA - Operation IceBridge patch.

Nov. 15, 2018

City-size impact crater found under Greenland ice

The first large crater ever found under ice, the discovery could possibly be linked to a controversial extinction theory.

Today, an international team of scientists describes what they say is a huge new impact crater that lies under northwestern Greenland’s Hiawatha Glacier. If confirmed, it would be the first impact crater on Earth discovered under ice, the team reports in the journal Science Advances. At an estimated 19 miles wide, it is larger than Washington, D.C., and would rank among the top 25 known craters in the world.


Image Credits: Brian T. Jacobs, NG Staff/Source: IceBridge BedMachine Greenland, ArcticDEM.

“Until 2015, no one had paid much attention to this part of the planet,” says study coauthor Joseph MacGregor, a glaciologist with the NASA Goddard Space Flight Center in Maryland. But that year, scientists began flying over the area with highly sensitive scanning instruments, such as lasers and radar, through NASA’s Operation IceBridge.

Like all IceBridge data, the scans were made public, and a group of Danish glaciologists noticed something interesting when they reviewed the material: A large, bowl-shaped depression was clearly visible in the bedrock under the ice.

“Could that be an impact crater? they asked,” MacGregor says. “They all laughed. But then they said, Maybe it is.”

As they looked closer, someone on the team also pointed out that a large meteorite in the collection at the Natural History Museum of Denmark—near where they parked their bicycles every day—had come from that same region of Greenland.

“We asked ourselves, could the two be linked?” says lead author Kurt Kjær, a glacial geologist and curator at the Natural History Museum of Denmark and the University of Copenhagen.

Uncovering a crater

To find out more, the Danish scientists reached out to MacGregor, who is the chief scientist for the IceBridge project. To get more high-resolution scans of the Hiawatha Glacier, the team also enlisted the Alfred Wegener Institute in Germany, which provided them with additional surveying flights in May 2016 carrying newer, more sensitive instruments. They also sent a ground team in July 2016 to map surrounding structures on the surface and collect samples of sediments that had drained out from under the glacier.

With the precise radar data, the team was able to more completely work out the shape of the proposed crater. The walls of the circular rim are roughly 1,050 feet above the floor of the crater, they found. The team also identified an uplifted area 164 to 230 feet high in the center of the crater, which Kjær says is an expected feature and is the result of the force of the strike.

Massive Crater Discovered Under Greenland Ice

In the sediment samples, the researchers found grains of what's known as shocked quartz—a rare form of the ubiquitous mineral that has been deformed in a characteristic way by very high-energy events, such as in a large impact. Some of the grains also showed a brown color known as toasting, again a sign of intense energy release. Other minerals showed signs of shock metamorphism, to the point of turning into glass.

Based on the size of the crater, the team estimates that the asteroid would have been around 0.75 miles across and would have weighed 11 to 12 billion tons as it entered the atmosphere. And based on their mineral analysis, they believe it was an iron-rich space rock—the same type of rock as the meteorite fragment in the museum, although more tests would need to be done to establish a firm link, Kjær notes.

Now that he knows the circular depression is there, Kjær adds that he can even see its outline on the surface of the ice.


Image above: Seen in pastel artwork based on the view from a NASA IceBridge flight, Greenland's Hiawatha Glacier holds a startling new secret—and raises new questions about Earth's recent past. ("Hiawatha Basin, Greenland," soft pastel on paper, 2017.) Image Credit: NASA.

MacGregor agrees: “I have a coffee mug with a three-inch map of Greenland on it. I can see the Hiawatha Glacier on there. So this really was hiding in plain sight.”
Icy impact

But impact crater expert Ludovic Ferriere of the Natural History Museum in Vienna, who was not associated with the study, is skeptical of these conclusions.

“I can say what they are presenting as shock quartz is definitely shock quartz,” says Ferriere, who is also a National Geographic Explorer. But he cautions that he would like to see a larger sample size of sediments tested, as he isn’t sure that the quartz taken from under the glacier necessarily came from the presumed impact crater.

Kjær counters that they have many more samples still to sort through, grain by grain. And based on their radar mapping of the drainage system under the glacier, “where could the material come from if it didn’t come from inside the glacier?”


Image above: Hiawatha Glacier has long been known but little studied, until recently. NASA/John Sonntag.

Ferriere also says that the uplift the team reports for such a large impact crater is too small for what should be expected. Either it isn’t what they suspect, or the uplift feature has been heavily eroded. Kjær responded that the impact through the ice sheet can explain the more muted central uplift, as well as the debris and sloping sediments they observed with radar.

Both Kjær and Ferriere agree that the next steps likely include additional analysis of the existing samples, including the possibility of radioisotope dating, as well as collecting more material from the site. Ideally, the scientists say it would be best to drill through the glacier—which is nearly 0.6 miles thick over the crater—and into the rock below. A heavy drilling operation in such a remote area would be challenging and expensive, but not without precedent.

“I think they have something here, but they make strong conclusions based on very preliminary data and a lot of gaps,” Ferriere says. “With drilling, they might find something very different.” As it stands, Ferriere argues, their discovery of the shock quartz “is like if you arrive on the scene of a murder and you find one poor guy there; he’s not necessarily the murderer.”

World-changing event?


The scientists also don’t currently have enough information to assign an age to the proposed impact crater, but based on their analysis, they have suggested bookends for the date of the event. Given the structure of the rock and ice that can be “read” with radar, the team believes that the glacier was in place at the time of the strike, and that the impact punched a hole in the ice and resulted in a significant amount of melting and refreezing. That would suggest that the impact happened sometime before the end of the Pleistocene epoch around 11,700 years ago.

“It’s likely quite young, geologically speaking,” MacGregor says. “It’s likely less than three million years old and possibly as young as 12,000 to 15,000 years old.”


Animation above: Two views of the Hiawatha crater region: one covered by the Greenland Ice Sheet, the other showing the topography of the rock beneath the ice sheet, including the crater. Animation Credits: NASA/Cindy Starr.

If the discovery holds, the Hiawatha Crater could therefore be a tantalizing new piece of evidence for a very controversial idea. Called the Younger Dryas impact hypothesis, the notion is that some kind of large impact occurred in northern North America about 10,900 to 12,900 years ago, during the Younger Dryas Ice Age. This impact, the idea goes, caused massive wildfires across much of the continent that in turn led to the extinction of many of the large Ice Age mammals, like mammoths and mastodons, as well as the human Clovis culture.

One big problem with this hypothesis has long been the lack of a suitably large impact crater. If it's real and the dates match up, the Hiawatha Crater could be a plausible explanation, MacGregor says: “It’s a very speculative idea, but if this does turn out to be [the link], it would have had an outsize impact on human history.”

“We do not discuss it in the paper, but I think it is a possibility,” Kjær adds. “This may generate a lot of discussion, and we need to find out. We won’t know until we have a proper date.”

Related links:

Science Advances: http://advances.sciencemag.org/content/4/11/eaar8173

NASA’s Operation IceBridge: https://www.nasa.gov/mission_pages/icebridge/index.html

Natural History Museum of Denmark: https://snm.ku.dk/english/

Images (mentioned), Animation (mentioned), Video, Text, Credits: National Geographic/Brian Clark Howard/NASA.

Greetings, Orbiter.ch

US Cargo Mission Slips a Day; Station Tests Free-Flying AI Assistant













ISS - Expedition 57 Mission patch.

November 15, 2018

The launch of the Cygnus space freighter from Northrop Grumman has slipped another day due to inclement weather at the Wallops Flight Facility on Virginia’s Atlantic coast. Cygnus is now scheduled to launch atop the Antares rocket Saturday at 4:01 a.m. EST with a much improved weather forecast.

The U.S. resupply ship will deliver approximately 7,400 pounds of food, fuel and supplies to the station two days later. Flight Engineer Serena Auñón-Chancellor will command the Canadarm2 robotic arm to capture Cygnus Monday at 5:20 a.m. Commander Alexander Gerst will back her up and monitor telemetry from the vehicle during its approach and rendezvous.


Image above: Flight Engineer Serena Auñón-Chancellor practices on a computer the maneuvers she will use with Canadarm2 robotic arm to capture the U.S. Cygnus space freighter on Monday. Image Credit: NASA.

The Progress 71 (71P) cargo craft from Russia is at the Baikonur Cosmodrome launch pad in Kazakhstan ready to blast off Friday at 1:14 p.m. EST. Prokopyev will be monitoring the Russian resupply ship when it arrives Sunday for an automated docking to the rear port of the Zvezda service module at 2:30 p.m.

The International Space Station Program is testing the use of artificial intelligence today to contribute to mission success aboard the orbital laboratory. Meanwhile, the space residents from the U.S., Germany and Russia continued more human research and prepared for the upcoming U.S. and Russian space deliveries.

CIMON, or Crew Interactive MObile CompanioN, is a free-flying robotic assistant based on artificial intelligence currently being tested on the station. The astronaut support device from ESA (European Space Agency) was powered up and commissioned today by the station commander inside the Columbus lab module. The CIMON technology seeks to demonstrate astronaut-robot interaction by answering crew questions, assisting with science experiments and navigating autonomously in the lab.


Image above: Flying over South Pacific Ocean, seen by EarthCam on ISS, speed: 27'569 Km/h, altitude: 418,00 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on November 15, 2018 at 19:46 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

Cosmonaut Sergey Prokopyev and fellow crewmates Gerst and Auñón-Chancellor started Thursday with ongoing eye checks. Gerst and Serena swapped roles as Crew Medical Officer scanning each other’s eyes including Prokopyev’s using an ultrasound device with guidance from a doctor on the ground. The data is downlinked to Earth real-time and helps scientists understand how microgravity affects astronaut vision as well as the components and shape of the eye.

Related links:

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

Cygnus space freighter: https://www.nasa.gov/feature/northrop-grumman-cygnus-launches-arrivals-and-departures/

Progress 71 (71P) cargo craft: https://www.nasa.gov/feature/progress-launches-arrivals-and-departures/

NASA TV: https://www.nasa.gov/nasatv

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

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

Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Finding an Elusive Star Behind a Supernova













NASA - Hubble Space Telescope patch.

Nov. 15, 2018


Located 65 million light-years away ia a blue supergiant star that once existed inside a cluster of young stars in the spiral galaxy NGC 3938, as shown in this artist's concept. It exploded as a supernova in 2017 and Hubble Space Telescope archival photos were used to locate the doomed progenitor star, as it looked in 2007. The star may have been as massive as 50 suns and burned at a furious rate, making it hotter and bluer than our Sun. It was so hot, it lost its outer layers of hydrogen and helium. When it exploded, astronomers categorized it as a Type Ic supernova because of the lack of hydrogen and helium in the supernova's spectrum.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/

Image, Animation, Text, Credits: NASA/Yvette Smith/ESA and J. Olmsted (STScI).

Greetings, Orbiter.ch