NASA Investigation Uncovers Cause of Two Science Mission Launch Failures

NASA - Launch Services Program (LSP) logo.

April 30, 2019

Image above: On Space Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences workers monitor NASA's Glory upper stack as a crane lifts it from a stationary rail for attachment to the Taurus XL rocket's Stage 0. Image Credit: NASA.

NASA Launch Services Program (LSP) investigators have determined the technical root cause for the Taurus XL launch failures of NASA’s Orbiting Carbon Observatory (OCO) and Glory missions in 2009 and 2011, respectively: faulty materials provided by aluminum manufacturer, Sapa Profiles, Inc. (SPI).

LSP’s technical investigation led to the involvement of NASA’s Office of the Inspector General and the U.S. Department of Justice (DOJ). DOJ’s efforts, recently made public, resulted in the resolution of criminal charges and alleged civil claims against SPI, and its agreement to pay $46 million to the U.S. government and other commercial customers. This relates to a 19-year scheme that included falsifying thousands of certifications for aluminum extrusions to hundreds of customers.

This is an artist’s concept of the Orbiting Carbon Observatory. Image credits: NASA/JPL

NASA’s updated public summary of the launch failures, which was published Tuesday, comes after a multiyear technical investigation by LSP and updates the previous public summaries on the Taurus XL launch failures for the OCO and Glory missions. Those public summaries concluded that the launch vehicle fairing — a clamshell structure that encapsulates the satellite as it travels through the atmosphere — failed to separate on command, but no technical root cause had been identified. From NASA’s investigation, it is now known that SPI altered test results and provided false certifications to Orbital Sciences Corporation, the manufacturer of the Taurus XL, regarding the aluminum extrusions used in the payload fairing rail frangible joint. A frangible joint is a structural separation system that is initiated using ordnance.

“NASA relies on the integrity of our industry throughout the supply chain. While we do perform our own testing, NASA is not able to retest every single component. That is why we require and pay for certain components to be tested and certified by the supplier,” said Jim Norman, NASA’s director for Launch Services at NASA Headquarters in Washington. “When testing results are altered and certifications are provided falsely, missions fail. In our case, the Taurus XLs that failed for the OCO and Glory missions resulted in the loss of more than $700 million, and years of people’s scientific work. It is critical that we are able to trust our industry to produce, test and certify materials in accordance with the standards we require. In this case, our trust was severely violated.”

 Artist concept of Glory satellite. Image Credit: NASA

To protect the government supply chain, NASA suspended SPI from government contracting and proposed SPI for government-wide debarment. The exclusion from government contracting has been in effect since Sept. 30, 2015. NASA also has proposed debarment for Hydro Extrusion Portland, Inc.,formerly known as SPI,and the company currently is excluded from contracting throughout the federal government.

“Due in large part to the hard work and dedication of many highly motivated people in the NASA Launch Services program, we are able to close out the cause of two extremely disappointing launch vehicle failures and protect the government aerospace supply chain,” said Amanda Mitskevich, LSP program manager at NASA’s Kennedy Space Center in, Florida. “It has taken a long time to get here, involving years of investigation and testing, but as of today, it has been worth every minute, and I am extremely pleased with the entire team’s efforts.”

To learn more about NASA’s Launch Services Program, visit:

https://www.nasa.gov/centers/kennedy/launchingrockets/index.html

NASA Launch Services Program (LSP): https://elvperf.ksc.nasa.gov/Pages/Default.aspx

Orbiting Carbon Observatory (OCO): http://www.nasa.gov/mission_pages/oco/main/index.html

NASA’s Orbiting Carbon Observatory (OCO) failure: https://www.nasa.gov/mission_pages/oco/news/oco-20090717.html

Glory mission: https://www.nasa.gov/mission_pages/Glory/news/mishap-board-report.html

Images (mentioned), Text, Credits: NASA/Sean Potter/Gina Anderson.

Greetings, Orbiter.ch

Space Research Continues on Station as NASA, SpaceX Move Off May 1 Launch

ISS - Expedition 59 Mission patch.

April 30, 2019

NASA has requested SpaceX move off from May 1 for the launch of the company’s 17th commercial resupply mission to the International Space Station.

On April 29, the space station team identified an issue with one of the station’s Main Bus Switching Units that distributes power to two of the eight power channels on the station.  There are no immediate concerns for the crew or the station. Teams are working on a plan to robotically replace the failed unit and restore full power to the station system. Additional information will be provided as it becomes available. The earliest possible launch opportunity is no earlier than Friday, May 3.

Image above: The Gulf of Mexico, Galveston Bay and Houston, Texas, the home of NASA’s Johnson Space Center, are pictured from the International Space Station 256 miles above the Lone Star State. Image Credit: NASA.

Meanwhile, the Expedition 59 crew explored a wide variety of microgravity science today including human research, robotics and space manufacturing techniques.

Flight Engineer David Saint-Jacques jotted down his impressions of space life in a private journal this morning for the Behavioral Core Measures study. Later he installed new incubator hardware inside the Space Automated Bioproduct Lab for the Kidney Cells experiment that seeks innovative treatments for humans on Earth and in space.

Image above: The International Space Station was pictured by an Expedition 56 crewmember aboard a departing Soyuz crew ship on Oct. 4, 2018. Image Credit: NASA.

Astrobee, a new free-flying robotic assistant, is being readied for testing today inside Japan’s Kibo lab module. NASA astronaut Anne McClain inspected and checked out the cube-shaped mini-robot’s components then activated the device to perform a flyaround. Astrobee could save the crew time performing routine maintenance duties and providing additional lab monitoring capabilities.

Engineers are also testing the feasibility of producing fiber optic cable in space. Microgravity reveals physical processes hidden by Earth’s gravity that may prove the superiority of space manufacturing. Flight Engineer Christina Koch contributed to that study today working on fiber samples in the Microgravity Science Glovebox that will be examined back on Earth for quality.

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

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

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

Behavioral Core Measures: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7537

Space Automated Bioproduct Lab: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1148

Fiber optic cable in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7630

Microgravity Science Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=341

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

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

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

Best regards, Orbiter.ch

Scientists Planning Now for Asteroid Flyby a Decade Away

Asteroid Watch logo.

April 30, 2019

On April 13, 2029, a speck of light will streak across the sky, getting brighter and faster. At one point it will travel more than the width of the full Moon within a minute and it will get as bright as the stars in the Little Dipper. But it won't be a satellite or an airplane - it will be a 1,100-foot-wide (340-meter-wide) near-Earth asteroid called 99942 Apophis that will cruise harmlessly by Earth, about 19,000 miles (31,000 kilometers) above the surface. That's within the distance that some of our spacecraft that orbit Earth.

Animation above: This animation shows the distance between the Apophis asteroid and Earth at the time of the asteroid's closest approach. The blue dots are the many man-made satellites that orbit our planet, and the pink represents the International Space Station. Animation Credits: NASA/JPL-Caltech.

The international asteroid research community couldn't be more excited.

This week at the 2019 Planetary Defense Conference in College Park, Maryland, scientists are gathering to discuss observation plans and science opportunities for the celestial event still a decade away. During a session on April 30, scientists will discuss everything from how to observe the event to hypothetical missions we could send out to the asteroid.

"The Apophis close approach in 2029 will be an incredible opportunity for science," said Marina Brozovi?, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, who works on radar observations of near-Earth objects (NEOs). "We'll observe the asteroid with both optical and radar telescopes. With radar observations, we might be able to see surface details that are only a few meters in size."

It's rare for an asteroid of this size to pass by Earth so close. Although scientists have spotted small asteroids, on the order of 5-10 meters, flying by Earth at a similar distance, asteroids the size of Apophis are far fewer in number and so do not pass this close to Earth as often.

Image above: Nine new radar images of near-Earth asteroid 2007 PA8 were obtained between Oct. 31 and Nov. 13, 2012. Image Credits: NASA/JPL-CalTech.

The asteroid, looking like a moving star-like point of light, will first become visible to the naked eye in the night sky over the Southern Hemisphere, flying above Earth from the east coast to the west coast of Australia. It will be mid-morning on the East Coast of the United States when Apophis is above Australia. It will then cross the Indian Ocean, and by the afternoon in the eastern U.S. it will have crossed the equator, still moving west, above Africa. At closest approach, just before 6 p.m. EDT, Apophis will be over the Atlantic Ocean - and it will move so fast that it will cross the Atlantic in just an hour. By 7 p.m. EDT, the asteroid will have crossed over the United States.

A team of astronomers at the Kitt Peak National Observatory discovered Apophis in June 2004. The astronomers were only able to detect the asteroid for two days before technical and weather issues prevented further observations. Luckily, another team rediscovered the asteroid at the Siding Spring Survey in Australia later that year. The observations caused quite a stir - initial orbital calculations revealed that the asteroid had a 2.7% chance of impacting Earth in 2029. Fortunately, additional observations completely ruled out that possibility.

Since its discovery, optical and radar telescopes have tracked Apophis as it continues on its orbit around the Sun, so we know its future trajectory quite well. Current calculations show that Apophis still has a small chance of impacting Earth, less than 1 in 100,000 many decades from now, but future measurements of its position can be expected to rule out any possible impacts.

The most important observations of Apophis will occur in 2029, when asteroid scientists around the world will have an opportunity to conduct a close-up study of the Apophis' size, shape, composition and possibly even its interior.

Near Earth Asteroids. Image Credit: ESA

At the conference, scientists will discuss questions like "How will Earth's gravity affect the asteroid as it passes by?," "Can we use Apophis' flyby to learn about an asteroid's interior?" and "Should we send a spacecraft mission to Apophis?"

"We already know that the close encounter with Earth will change Apophis' orbit, but our models also show the close approach could change the way this asteroid spins, and it is possible that there will be some surface changes, like small avalanches," said Davide Farnocchia, an astronomer at JPL's Center for Near Earth Objects Studies (CNEOS), who is co-chairing the April 30 session on Apophis with Brozovi?.

"Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs)," said Paul Chodas, director of CNEOS. "By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense."

Related article:

NASA Rules Out Earth Impact in 2036 for Asteroid Apophis
https://orbiterchspacenews.blogspot.com/2013/01/nasa-rules-out-earth-impact-in-2036-for.html

Related links:

2019 Planetary Defense Conference: http://pdc.iaaweb.org/

For more information about asteroids and near-Earth objects, visit: http://www.jpl.nasa.gov/asteroidwatch Updates about near-Earth objects are also available by following AsteroidWatch on Twitter at http://www.twitter.com/asteroidwatch .

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/JPL/DC Agle.

Greetings, Orbiter.ch

Crew Waits for Dragon Mission While Teams Troubleshoot Power Issue

ISS - Expedition 59 Mission patch.

April 29, 2019

A SpaceX Dragon cargo craft is poised to liftoff this week from Florida to the International Space Station. The Expedition 59 crew will welcome Dragon when it arrives three days later carrying nearly 5,500 pounds of cargo.

Dragon will be encapsulated atop the Falcon 9 rocket at Cape Canaveral Air Force Station for a countdown to its Wednesday launch at 3:59 a.m. EDT. Astronaut David Saint-Jacques will be at the controls of the robotics workstation Saturday commanding the Canadarm2 to capture Dragon around 6:45 a.m. NASA TV will broadcast the launch and capture activities live.

Image above: The Aurora and the night sky above Earth’s atmosphere are pictured from the space station. A portion of the station’s solar arrays and a pair of nitrogen/oxygen recharge system tanks are pictured in the foreground. Image Credit: NASA.

He and fellow flight engineers Nick Hague, Anne McClain and Christina Koch are familiarizing themselves with the complex cargo unpacking procedures today. Dragon is also carrying external cargo, including the Orbiting Carbon Observatory-3, that will be removed by robotics controllers and installed on the station.

In the meantime, the space residents have been filming a virtual reality experience aboard the orbital lab. Today, McClain set up the 360-degree camera in the U.S. Destiny lab module to film herself talking about her space experience as her crewmates work around her.

Koch is helping engineers learn how to produce high quality optical fibers on the space station. The weightless environment of space provides the opportunity to explore manufacturing techniques that are superior to those on Earth. Results could improve space technologies as well as provide more Earth-bound benefits.

 Flying over Aurora, Animation Credit: NASA

On the Russian side of the station, Commander Oleg Kononenko focused on lab maintenance ensuring life support systems are in tip-top shape. Flight Engineer Alexey Ovchinin spent a couple of hours cleaning Orlan spacesuits before checking radiation sensors and replacing fire extinguishers.

Monday morning, teams identified an issue with the International Space Station’s electrical power system and are working to identify the root cause and restore full power to the system. There are no immediate concerns for the crew or the station. An issue is being worked with a Main Bus Switching Unit (MBSU) that distributes electrical power to two of the eight power channels on the station. Flight controllers have been working to route power through the remaining six power channels. Electrical power generated by the station’s solar arrays is fed to all station systems through these power channels. Discussions are underway to determine any impacts to SpaceX’s CRS-17 cargo resupply mission targeted for launch May 1.

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

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

Canadarm2: https://www.nasa.gov/mission_pages/station/structure/elements/mobile-servicing-system.html

Orbiting Carbon Observatory-3 (OCO-3): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1786

Virtual reality experience: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7877

U.S. Destiny lab module: https://www.nasa.gov/mission_pages/station/structure/elements/us-destiny-laboratory

High quality optical fibers: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7630

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

Best regards, Orbiter.ch

Opportunity's Final Traverse Map

NASA - Mars Exploration Rover B (MER-B) patch.

April 29, 2019

This final traverse map for NASA's Opportunity rover shows where the rover was located within Perseverance Valley on June 10, 2018, the last date it made contact with its engineering team.

Visible in this map is a yellow traverse route beginning at Opportunity's landing site, Eagle Crater, and ranging 28.06 miles (45.16 kilometers) to its final resting spot on the rim of Endeavour Crater. The rover was descending down into the crater in Perseverance Valley when the dust storm ended its mission.

Opportunity: NASA Rover Completes Mars Mission

Video above: Drive along with the NASA’s Opportunity Mars rover and hear the voices of scientists and engineers behind the mission. Designed to run for 90 days, the exploration spanned more than 15 years from 2004 to 2019. Along the way, it discovered definitive proof of liquid water on ancient Mars and set the off-world driving record. Video Credits: NASA/JPL.

Mars Exploration Rover (MER). Image Credits: NASA/JPL-Caltech

Related articles:

NASA's Record-Setting Opportunity Rover Mission on Mars Comes to End
https://orbiterchspacenews.blogspot.com/2019/02/nasas-record-setting-opportunity-rover.html

Six Things to Know About NASA's Opportunity Mars Rover
https://orbiterchspacenews.blogspot.com/2019/02/six-things-to-know-about-nasas.html

Related link:

Mars Exploration Rovers (Spirit and Opportunity): https://www.nasa.gov/mission_pages/mer/index.html

Image, Video (mentioned), Text, Credits: NASA/Yvette Smith/JPL-Caltech/MSSS.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of April 22, 2019

ISS - Expedition 59 Mission patch.

April 29, 2019

Astronauts aboard the International Space Station installed a variety of hardware and set up science experiments that arrived via a Cygnus resupply ship last week. Crew members also collected samples for investigations.

Here are details on some of the scientific activities the Expedition 59 crew members conducted the week of April 22:

Testing the Response of New Materials to the Space Environment

Image above: NASA astronauts Anne McClain and Nick Hague install cartridges into the Materials ISS Experiment Flight Facility (MISSE-FF) in the JEM Airlock. Alpha Space’s facility provides a unique platform that is available for the private sector, as well as other government entities, to conduct applied materials testing or technical demonstrations. Image Credit: NASA.

The Materials ISS Experiment Flight Facility (MISSE-FF) platform provides the ability to test materials, coatings, and components or other larger experiments in the harsh environment of space, which is virtually impossible to do on Earth. Testing in low-Earth orbit (LEO) allows investigators to determine how materials react to exposure to ultraviolet radiation (UV), atomic oxygen (AO), ionizing radiation, ultrahigh vacuum (UHV), charged particles, thermal cycles, electromagnetic radiation, and micro-meteoroids in the LEO environment. Crewmembers installed three new MISSE Sample Containers (MSCs) onto the MISSE Transfer Tray (MTT) in the Japanese Equipment Module (JEM) airlock for robotic attachment to the MISSE-FF facility on the outside of the space station.

Image above: Flying over North Atlantic Ocean, seen by EarthCam on ISS, speed: 27'664 Km/h, altitude: 405,64 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 April 29, 2019 at 11:29 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

Investigating microbe adaptation to microgravity

The Experimental Evolution of Bacillus subtilis Populations in Space: MVP-02 investigation seeks to understand how organisms adapt to the space environment, an important component of future space exploration. Microbes may play fundamental roles in the development of biologically-based closed-loop regenerative life support, in-situ resource utilization, and have extensive interactions with human and plant hosts. Further, microbes may pose challenges through virulence and contamination and as nuisance factors such as biofilms in water supply and ventilation systems.  Last week, the crew installed the MVP-02 platform onto Express Rack 4 and took documentation photos.

Manufacturing fiber optic cable in microgravity

Image above: Canadian Space Agency astronaut David Saint-Jacques shown in front of the Space Fibers facility. Space Fibers evaluates methods and materials for producing fiber optic cable in microgravity, producing improved quality fiber over what can be manufactured on the ground. Image Credit: NASA.

The crew also installed a sample cartridge into the Space Fibers facility for a run initiated by the ground team. Space Fibers evaluates a method for producing fiber optic cable from a blend of zirconium, barium, lanthanum, sodium and aluminum, called ZBLAN, in space. ZBLAN glass, theoretically one hundred times more transparent than silica-based glass, is exceptional for fiber optics. However, when it is produced on Earth, imperfections degrade its performance. Microgravity suppresses two mechanisms that commonly degrade this fiber, and previous studies showed improved properties in ZBLAN fiber drawn in microgravity compared to that fabricated on the ground.

Other investigations on which the crew performed work:

- Rodent Research-12 (RR-12) examines the effects of spaceflight on the function of antibody production and immune memory using a mouse model: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7868

Image above: SS crew member installs an Experiment Cube in the International Commercial Experiment Cubes (ICE Cube) facility. This facility offers flexibility to host many different experiments for research, technology demonstration or educational objectives. Image Credit: NASA.

- International Commercial Experiment Cubes (ICE Cubes): The crew installed Experiment Cubes in the ICE Cube facility, is an experiment platform that offers flexibility to host many different experiments for research, technology demonstration or educational objectives: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7607

- The SUBSA investigation crystallizes melts in microgravity to improve understanding of solidification phenomena and crystal production: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=308

- Fluid Shifts characterizes fluid redistribution and compartmentalization in the body associated with long-duration space flight and correlates these findings with vision changes and other elements of the Spaceflight Associated Neuro-ocular (SANS) syndrome.  Understanding effects of these changes helps prepare for long duration missions such as the planned journey to Mars: https://www.nasa.gov/content/fluid-shifts-study-advances-journey-to-mars

- Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

- RADI-N2, a Canadian Space Agency investigation, characterizes the ISS neutron environment and the risk posed to the crew members’ health in order to develop advanced protective measures for future spaceflight. Bubble detectors used in this investigation are designed detect neutrons and ignore other radiation: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=874

Space to Ground: Extreme Exposure: 04/26/2019

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

Materials ISS Experiment Flight Facility (MISSE-FF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7515

Experimental Evolution of Bacillus subtilis Populations in Space (MVP-02): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7660

Space Fibers: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7375

Spot the Station: https://spotthestation.nasa.gov/

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), Video (NASA), Text, Credits: NASA/Michael Johnson/Jorge Sotomayor, Lead Increment Scientist Expeditions 59/60/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Scientists get to the bottom of a ‘spitting’ black hole

ESA - Integral Mission patch.

29 April 2019

Data from ESA’s Integral high-energy observatory have helped shed light on the workings of a mysterious black hole found spitting out ‘bullets’ of plasma while rotating through space.

The black hole is part of a binary system known as V404 Cygni and is sucking in material from a companion star. It is located in our Milky Way, some 8000 light-years away from Earth, and was first identified in 1989, when it caused a huge outburst of high-energy radiation and material.

Black hole spitting out ‘bullets’ of plasma

After 26 years of dormancy, it woke up again in 2015, becoming for a short period of time the brightest object in the sky observable in high-energy X-rays.

Astronomers from all over the world pointed their ground and space-based telescopes towards the celestial object, and discovered that the black hole was behaving somewhat strangely.

A new study, based on data collected during the 2015 outburst, has now revealed the inner workings of this cosmic monster. The results are reported today in the journal Nature.

“During the outburst we observed details of the jet emissions when material is ejected at a very high speed from the vicinity of the black hole,” says Simone Migliari, an astrophysicist at ESA who is a co-author on the paper.

“We can see the jets shooting out in different directions on a timescale of less than an hour, which means that the inner regions of the system are rotating quite fast.”

Usually astronomers see the jets shooting straight out from the poles of black holes, perpendicular to the surrounding disc of material that is accreted from the companion star.

Black hole and companion star

Previously, there had only been one black hole observed with a rotating jet. It was, however, rotating much slower, completing one cycle in about six months.

The astronomers could observe the V404 Cygni jets in radio waves using telescopes like those of the Very Long Baseline Array in the US.

Meanwhile, high-energy X-ray data from Integral and other space observatories helped them decode what was happening at the same time inside the inner region of the 10 million kilometre-wide accretion disc. This was important since it is the mechanics of the disc that causes the jet’s strange behaviour.

“What’s different in V404 Cygni is that we think the disc of material and the black hole are misaligned,” says Associate Professor James Miller-Jones, from the International Centre for Radio Astronomy Research (ICRAR) at Curtin University, Australia, who is the lead author of the new paper.

“This appears to be causing the inner part of the disc to wobble like a spinning top that is slowing down, and fire jets out in different directions as it changes orientation.”

Tilted accretion disc

During the outburst, a large amount of the surrounding material was falling into the black hole at once, temporarily increasing the accretion rate of disc material towards the black hole and resulting in a sudden surge of energy. This was seen by Integral as an abrupt increase of the X-ray emission.

Integral’s observations were used to estimate the energy and geometry of the accretion onto the black hole, which in turn were crucial to understand the link between the incoming and outflowing material to create a complete picture of the situation.

“With Integral, we were able to keep looking at V404 Cygni continuously for four weeks, while other high-energy satellites could only take shorter snapshots,” says Erik Kuulkers, Integral Project Scientist at ESA.

Integral high-energy observatory

“The X-ray data support a model where the inner part of the accretion disc is tilted with respect to the rest of the system, most likely due to the spin of the black hole being inclined with respect to the orbit of the companion star,” explains Simone.

Scientists have been studying what caused this strange misalignment. One possibility is that the black hole spin axis may have been tilted by the ‘kick’ received during the supernova explosion that created it.

“The results would fit in a scenario, also studied in recent computer simulations, where the accretion flow in the vicinity of the black hole and the jets can rotate together,” says Erik.

“We should expect similar dynamics in any strongly-accreting black hole whose spin is misaligned with the inflowing gas, and we will have to take into account varying jet inclination angles when interpreting observations of black holes across the Universe.”

Notes for editors

“A rapidly-changing jet orientation in the stellar-mass black hole V404 Cygni” by J. C. A. Miller-Jones et al is published in Nature: https://www.nature.com/articles/s41586-019-1152-0

Integral, the International Gamma-ray Astrophysics Laboratory, was launched on 17 October 2002. It is an ESA project with instruments and a science data centre funded by ESA Member States (especially the Principal Investigator countries: Denmark, France, Germany, Italy, Spain and Switzerland), and with the participation of Russia and the USA. The mission is dedicated to spectroscopy and imaging of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in X-ray (3–35 keV) and optical (V-band, 550 nm) wavelengths.

Integral: http://sci.esa.int/integral/

Images, Text, Credits: ESA/Markus Bauer/Erik Kuulkers/Simone Migliari/International Centre for Radio Astronomy Research (ICRAR)/Pete Wheeler/James Miller-Jones.

Greetings, Orbiter.ch