samedi 20 mars 2021

SpaceX to Fly Another Starship Prototype (SN11)

 







SpaceX - Starship (unofficial) patch.


March 20, 2021

Elon Musk says construction of a new Starship rocket prototype is nearing completion. His test flight will not be long in coming.

The new Starship prototype test is coming soon. On Twitter, Elon Musk said on March 17, 2021 that preparations for the eleventh takeoff were on track: the craft itself is almost ready. There is due to be a static firing very soon, in order to examine the good behavior of the rocket. Observations around the test site show that this final examination is imminent.

Starship SN11 arrives at Pad B. Image Credit: SpaceX

The SN11 prototype (Serial Number 11) must resolve a problem that was observed with the SN10: the three engines of the rocket did not develop sufficient thrust to sufficiently slow the machine upon landing. It did land, but at excessive speed. The structure of the SN10 then underwent significant deformations, on the landing gear side as well as on the lower part of the rocket.

A helium incident observed with the previous prototype

In the days following this essay, some clarification was provided by Elon Musk himself. There was a problem with the helium, which was originally used to pressurize the methane tank and thus solve a problem observed during the SN8 test (a pressurization problem, in fact). At that time, Elon Musk added that SN11 was being corrected to avoid this scenario.


Image above: In this photo, the SN10 prototype has reactivated its engines and is in the process of tipping into an upright position to prepare for landing. He will succeed. Before exploding ten minutes later. Image Credit: SpaceX.

SN11 will be the fourth high altitude flight. The previous two, SN8 and 9, exploded on landing. SN10 had known a somewhat happier epilogue, because it had been able to land before ending up in confetti ten minutes later. SpaceX is set to offer a live broadcast of this test again - you'll have to be on the lookout, as the announcement often comes just minutes before the launch.

Starship | SN10 | High-Altitude Flight Recap

Starship is to be SpaceX's versatile ship in the medium and long term: it will replace the Falcon 9 and its heavy version, Falcon Heavy, for its missions of putting satellites into orbit, delivering equipment and supplies for the ISS and beyond, and astronaut transport. It is also with the Starship that SpaceX will organize a flyby of the Moon in 2023 for a few space tourists.

SpaceX: https://www.spacex.com/

Images (mentioned), Video, Text, Credits: SpaceX/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

vendredi 19 mars 2021

SAGE III Carries on Critical Measurements of Stratospheric Aerosols and Ozone

 







ISS - SAGE III Mission patch.


Mar 19, 2021

On the fourth anniversary of its first-light measurements, we are taking a look at some of the critical data collected by NASA's Stratospheric Aerosol and Gas Experiment III (SAGE III) aboard the International Space Station. Launched to the station in February 2017, SAGE III is the most recent in a series of SAGE instruments that have measured stratospheric gases and aerosols from space. The SAGE family of instruments started in 1979 and is one of NASA’s longest-running Earth-observing programs.

SAGE III on the ISS: Continuing Important Observations of the Stratosphere

Video Credits: Credits: Allison McMahon (SSAI): Producer; Haley Reed (ADNET): Producer; David Flittner (NASA/LaRC): Scientist; Marilee Roell (NASA/LaRC): Scientist; Jamie Nehrir (NASA/LaRC): Engineer; Kevin Leavor (SSAI): Scientist; NASA's Goddard Space Flight Center Conceptual Image Lab; and NASA’s Scientific Visualization Studio(SVS).

Data from SAGE II helped confirm human-driven changes to the ozone layer, which contributed to the 1987 Montreal Protocol that banned some of the most destructive industrially-produced ozone-depleting chemicals. Stratospheric ozone acts as a sunscreen for the Earth, filtering out harmful solar radiation by absorbing some of the Sun's ultraviolet rays, providing people, animals and plants some protection from that harmful radiation.

This latest SAGE III instrument is helping scientists monitor the recovery of ozone resulting from the reduction in emissions of ozone-depleting substances called for under the Montreal Protocol. SAGE III has also measured the intrusion of aerosols into the stratosphere from intense wildfires in Australia and California, and from volcanic eruptions. Those aerosols, which can remain in the stratosphere for months or even years, can lead to variability in the climate record. Water vapor, a potent greenhouse gas that can be lofted into the stratosphere by extreme storms, is also visible to SAGE III. Though it's normal to have some water vapor in the stratosphere, using SAGE data, scientists can better understand how year-to-year changes in tropical weather affect the amount of water vapor in regions of the stratosphere influenced by the tropical weather circulation.

SAGE III instrument on ISS. Image Credit: NASA

SAGE III makes measurements using solar and lunar occultation, a technique that involves looking at light from the Sun or Moon as it passes through Earth's atmosphere at the edge, or limb, of the planet. The SAGE III payload on the space station is managed by NASA's Langley Research Center in Hampton, Virginia and was developed in partnership with the European Space Agency, Ball Aerospace Technology Corporation, and NASA's Johnson Space Center in Houston.

Related links:

SAGE-III: https://directory.eoportal.org/web/eoportal/satellite-missions/i/iss-sage-3

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

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

Video (mentioned), Image (mentioned), Text, Credits: NASA Langley Research Center/Joe Atkinson.

Greetings, Orbiter.ch

Three Crewmates Complete Short Station Trip in Soyuz Crew Ship

 






ROSCOSMOS - Russian Vehicles patch.


March 19, 2021

The Expedition 64 crew members who arrived to the International Space Station Oct. 14, 2020, have successfully relocated their Soyuz MS-17 spacecraft. Expedition 64 Flight Engineer Kate Rubins of NASA and Commander Sergey Ryzhikov and Sergey Kud-Sverchkov, both of the Russian Space Agency Roscosmos, undocked from the Earth-facing port of the station’s Rassvet module at 12:38 p.m. EDT, and Ryzhikov successfully piloted the spacecraft and docked again at the space-facing Poisk port at 1:12 p.m.


Image above: The Soyuz MS-17 crew ship, with three Expedition 64 crew members inside, is pictured after undocking from the Rassvet module beginning its short trip to the Poisk module. Image Credit: NASA TV.

The relocation opens the Rassvet port for the arrival April 9 of another Soyuz, designated Soyuz MS-18, which will carry NASA’s Mark Vande Hei and Roscosmos’ Oleg Novitsky and Pyotr Dubrov to join the space station crew after launching from the Baikonur Cosmodrome in Kazakhstan.

Soyuz MS-17 relocation

Rubins, Ryzhikov, and Kud-Sverchkov will conclude their six-month science mission aboard the station and return to Earth April 17 in the Soyuz MS-17.

This was the 15th overall Soyuz port relocation and the first since August 2019.

Related links:

ROSCOSMOS Press Release: Перелёт с причала на причал / Flight from dock to dock
https://www.roscosmos.ru/30393/

Expedition 64: https://www.nasa.gov/mission_pages/station/expeditions/expedition64/index.html

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

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

Best regards, Orbiter.ch

Hubble Captures Re-energized Planetary Nebula

 







NASA & ESA - Hubble Space Telescope patch.


Mar 19, 2021


Located around 5,000 light-years away in the constellation of Cygnus (the Swan), Abell 78 is an unusual type of planetary nebula.

After exhausting the nuclear fuel in their cores, stars with a mass of around 0.8 to eight times the mass of our Sun collapse to form dense and hot white dwarf stars. As this process occurs, the dying star will throw off its outer layers of material, forming an elaborate cloud of gas and dust known as a planetary nebula. This phenomenon is not uncommon, and planetary nebulae are a popular focus for astrophotographers because of their often beautiful and complex shapes. However, a few like Abell 78 are the result of a so-called “born again” star.

Although the core of the star has stopped burning hydrogen and helium, a thermonuclear runaway at its surface ejects material at high speeds. This ejecta shocks and sweeps up the material of the old nebula, producing the filaments and irregular shell around the central star seen in this image, which features data from Hubble’s Wide Field Camera 3 and the Panoramic Survey Telescope and Rapid Response System.


 Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: European Space Agency (ESA)/NASA/Lynn Jenner/Image, Animation Credits: ESA/Hubble & NASA, M. Guerrero; Acknowledgment: Judy Schmidt.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of March 15, 2021

 






ISS - Expedition 64 Mission patch.


Mar 19, 2021

International Space Station (ISS), an orbital laboratory. Animation Credit: ESA

The week of March 15, crew members aboard the International Space Station conducted scientific investigations, including studies of the melting-solidification process and changes in muscle properties in microgravity and tests of protective coatings and robot maneuvers.  

The seven crew members currently inhabiting the station include four from NASA’s Commercial Crew Program, providing increased crew time for science activities on the orbiting lab. The space station has been continuously inhabited by humans for 20 years and has supported many scientific breakthroughs during that time. The station provides a platform for long-duration research in microgravity and for learning to live and work in space, experience that supports Artemis, NASA’s program to go forward to the Moon and on to Mars.


Image above: This image shows the mouth of the Mississippi River emptying into the Gulf of Mexico south of New Orleans, Louisiana, as the International Space Station orbits 262 miles above. Image Credit: Roscosmos.

Here are details on some of the microgravity investigations currently taking place:

Melting and solidifying transparent materials

Crew members installed hardware for Transparent Alloys, a set of five experiments from ESA (European Space Agency) to improve the understanding of melting-solidification processes in plastics. Microgravity removes the effects of walls and convection during the process, enabling better observation of the dynamics of pattern formation. Solidification of organic transparent substances serves as a model for solidification of metallic alloys, so these studies add to basic knowledge for solidification dynamics and microstructure formation. Results could have implications for industrial casting processes and the metallic products manufactured using them.

Monitoring markers for muscle health

Existing data on muscle atrophy caused by disuse suggest that during spaceflight, muscle stiffness decreases, particularly in those muscles most important for postural support and movement, such as running and walking. Myotones, an investigation from ESA, uses biomarkers to observe the biochemical properties of muscles during long-term spaceflight. Exercise countermeasures performed during flight may improve or even recover these properties. By providing insight into principles of human resting muscle tone, results could help support development of new treatments for rehabilitation, both on Earth and for future space missions. Crew members marked locations of the seven muscles, two tendons, and one area of fascia studied in the investigation and took measurements with the Myotones device during the week.

Better paint protection in space


Image above: The colored strips visible on the exterior of the space station in this image are different coatings exposed to the environment of space for the STP-H5 ICE investigation, conducted to determine their stability for use protecting the outside of spacecraft and as markings to guide robotic and human navigation. Image Credit: NASA.

In space, harsh radiation and extreme temperatures corrode paint and coatings protecting the outside of spacecraft, which could potentially damage the hull and pose a risk to crew members. STP-H5 ICE exposes new coatings to space for two years to determine their stability in that environment. Optical coatings also are used for special markings that robotic and human navigators rely on to capture or repair spacecraft. Results could contribute to further improvement in coatings for both uses. Crew members documented samples during the week.

Great hopping robots!

Robots used in space either free-fly or zero-g climb by grasping handrails with their robotic manipulators. Hopping maneuvers offer a potentially faster method of movement that uses less propellant or fuel. Astrobatics tests these maneuvers using one of the station’s free-flying Astrobee robots, which uses its perching arms and handrails on the space station to demonstrate vehicle guidance and control. The ability to hop between locations in a spacecraft or on a planet expands the mobility of a robotic vehicle. Robotics have a wide range of applications on space missions, including assisting crew on intra- or extravehicular activities, equipment servicing, removal of orbital debris, conducting on-orbit assembly, grappling and moving equipment and samples, and exploration. During the week, crew members conducted a session for the experiment.

Other investigations on which the crew performed work:


Image above: Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi and NASA astronaut Michael Hopkins pose with plants growing inside a container for Asian Herb in Space, a study on cultivating fast-growing plants used for traditional medicine and food flavoring. Image Credit: NASA.

- An investigation from the Japan Aerospace Exploration Agency (JAXA), Asian Herb in Space studies several fast-growing plants used for traditional medicine and flavoring food, examining differences in their aroma that may result from microgravity-related cellular changes. Results could benefit future plant growth efforts in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2052

- Ribosome Profiling, an investigation from JAXA, aims to provide insight into how gravity affects gene expression, with a special focus on translation regulation, using a state-of-art technique. The work could help researchers understand why aging-related changes often occur in space and may lead to better treatments for those changes.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7985


Image above: NASA astronaut Mike Hopkins is shown with the HUNCH Tape Dispenser developed by high school students to enable one-handed operation for crew members. Image Credit: NASA.

- Crew members regularly use tape for a variety of tasks, but tape currently used often must be cut with scissors, requiring two hands. HUNCH Tape Dispenser tests a dispenser designed by high school students that crew members can operate with one hand. It could improve efficiency of operations and scientific research on the space station.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7957

- Standard Measures collects a set of core measurements from astronauts before, during, and after long-duration missions to create a data repository to monitor and interpret how humans adapt to living in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711

- Loss of muscle mass and strength represent a major challenge for astronauts on future long space voyages. Micro-16 uses a model organism, the C. elegans worm, to test whether decreased expression of muscle proteins is associated with decreased strength.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7654

- Antimicrobial Coatings tests a coating to control microbial growth on several different materials that represent high-touch surfaces. Some microbes change characteristics in microgravity, potentially creating new risks to crew health and spacecraft.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8352

- Food Acceptability looks at how the appeal of food changes during long-duration missions. Whether crew members like and actually eat foods directly affects caloric intake and associated nutritional benefits.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

Space to Ground: Tournament Earth: 03/19/2021

Related links:

Expedition 64: https://www.nasa.gov/mission_pages/station/expeditions/expedition64/index.html

Transparent Alloys: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8215

Myotones: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7573

STP-H5 ICE: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1749

Astrobatics: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7841

ISS National Lab: https://www.issnationallab.org/

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

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

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

Images (mentioned), Animation (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/John Love, ISS Research Planning Integration Scientist.

Best regards, Orbiter.ch

jeudi 18 mars 2021

Hubble Shows Torrential Outflows from Infant Stars May Not Stop Them from Growing

 







NASA - Hubble Space Telescope patch.


March 18, 2021

Though our galaxy is an immense city of at least 200 billion stars, the details of how they formed remain largely cloaked in mystery.

Scientists know that stars form from the collapse of huge hydrogen clouds that are squeezed under gravity to the point where nuclear fusion ignites. But only about 30 percent of the cloud's initial mass winds up as a newborn star. Where does the rest of the hydrogen go during such a terribly inefficient process?


Image above: These four images taken by NASA's Hubble Space Telescope reveal the chaotic birth of stars in the Orion complex, the nearest major star-forming region to Earth. The snapshots show fledgling stars buried in dusty gaseous cocoons announcing their births by unleashing powerful winds and pairs of spinning, lawn-sprinkler-style jets shooting off in opposite directions. Near-infrared light pierces the dusty region to unveil details of the birthing process. The stellar outflows are carving out cavities within the hydrogen gas cloud. This relatively brief birthing stage lasts about 500,000 years. Although the stars themselves are shrouded in dust, they emit powerful radiation, which strikes the cavity walls and scatters off dust grains, illuminating in infrared light the gaps in the gaseous envelopes. Astronomers found that the cavities in the surrounding gas cloud sculpted by a forming star's outflow did not grow regularly as they matured, as theories propose. The protostars were photographed in near-infrared light by Hubble's Wide Field Camera 3. The images were taken Nov. 14, 2009, and Jan. 25, Feb. 11, and Aug. 11, 2010. Image Credits: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo).

It has been assumed that a newly forming star blows off a lot of hot gas through lightsaber-shaped outflowing jets and hurricane-like winds launched from the encircling disk by powerful magnetic fields. These fireworks should squelch further growth of the central star. But a new, comprehensive Hubble survey shows that this most common explanation doesn't seem to work, leaving astronomers puzzled.

Researchers used data previously collected from NASA's Hubble and Spitzer space telescopes and the European Space Agency's Herschel Space Telescope to analyze 304 developing stars, called protostars, in the Orion Complex, the nearest major star-forming region to Earth. (Spitzer and Herschel are no longer operational).

In this largest-ever survey of nascent stars to date, researchers are finding that gas-clearing by a star's outflow may not be as important in determining its final mass as conventional theories suggest. The researchers' goal was to determine whether stellar outflows halt the infall of gas onto a star and stop it from growing.

Instead, they found that the cavities in the surrounding gas cloud sculpted by a forming star's outflow did not grow regularly as they matured, as theories propose.

"In one stellar formation model, if you start out with a small cavity, as the protostar rapidly becomes more evolved, its outflow creates an ever-larger cavity until the surrounding gas is eventually blown away, leaving an isolated star," explained lead researcher Nolan Habel of the University of Toledo in Ohio.

"Our observations indicate there is no progressive growth that we can find, so the cavities are not growing until they push out all of the mass in the cloud. So, there must be some other process going on that gets rid of the gas that doesn't end up in the star."

The team's results will appear in an upcoming issue of The Astrophysical Journal:
https://iopscience.iop.org/journal/0004-637X


Image above: This ground-based image offers a wide view of the entire Orion cloud complex, the closest major star-forming region to Earth. The red material is hydrogen gas ionized and heated by ultraviolet radiation from massive stars in Orion. The stars are forming in clouds of cold hydrogen gas that are either invisible or appear as dark regions in this image. The crescent shape is called Barnard's Loop and partly wraps around the winter constellation figure of Orion the Hunter. The hunter's belt is the diagonal chain of three stars at image center. His feet are the bright stars Saiph (bottom left) and Rigel (bottom right). This landscape encompasses tens of thousands of newly forming stars bursting to life. Many are still encased in their natal cocoons of gas and dust and only seen in infrared light. The undulating line of yellow dots, beginning at lower left, is a superimposed image of 304 nascent stars taken by NASA's Hubble Space Telescope. This landscape encompasses tens of thousands of newly forming stars bursting to life. Many are still encased in their natal cocoons of gas and dust and only seen in infrared light. Researchers used NASA's Hubble and Spitzer space telescopes and the European Space Agency's Herschel Space Telescope to analyze how young stars' powerful outflows carve out cavities in the vast gas clouds. The study is the largest-ever survey of developing stars. Image Credits: Image courtesy of R. B. Andreo, DeepSkyColors.com; Data Overlay: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo).

A Star is Born

During a star's relatively brief birthing stage, lasting only about 500,000 years, the star quickly bulks up on mass. What gets messy is that, as the star grows, it launches a wind, as well as a pair of spinning, lawn-sprinkler-style jets shooting off in opposite directions. These outflows begin to eat away at the surrounding cloud, creating cavities in the gas.

Popular theories predict that as the young star evolves and the outflows continue, the cavities grow wider until the entire gas cloud around the star is completely pushed away. With its gas tank empty, the star stops accreting mass – in other words, it stops growing.

To look for cavity growth, the researchers first sorted the protostars by age by analyzing Herschel and Spitzer data of each star's light output. The protostars in the Hubble observations were also observed as part of the Herschel telescope's Herschel Orion Protostar Survey.

Hubble Space Telescope (HST). Animation Credits: NASA/ESA

Then the astronomers observed the cavities in near-infrared light with Hubble's Near-infrared Camera and Multi-object Spectrometer and Wide Field Camera 3. The observations were taken between 2008 and 2017. Although the stars themselves are shrouded in dust, they emit powerful radiation which strikes the cavity walls and scatters off dust grains, illuminating the gaps in the gaseous envelopes in infrared light.

The Hubble images reveal the details of the cavities produced by protostars at various stages of evolution. Habel's team used the images to measure the structures' shapes and estimate the volumes of gas cleared out to form the cavities. From this analysis, they could estimate the amount of mass that had been cleared out by the stars' outbursts.

Hubble Shows Torrential Outflows from Infant Stars May Not Stop Them from Growing

Video above: Though our galaxy is an immense city of at least 200 billion stars, the details of how they formed remain largely cloaked in mystery. Scientists know that stars form from the collapse of huge hydrogen clouds that are squeezed under gravity to the point where nuclear fusion ignites. But only about 30 percent of the cloud’s initial mass winds up as a newborn star. Where does the rest of the hydrogen go during such a terribly inefficient process? Video Credits: NASA Goddard Space Flight Center.

"We find that at the end of the protostellar phase, where most of the gas has fallen from the surrounding cloud onto the star, a number of young stars still have fairly narrow cavities," said team member Tom Megeath of the University of Toledo. "So, this picture that is still commonly held of what determines the mass of a star and what halts the infall of gas is that this growing outflow cavity scoops up all of the gas. This has been pretty fundamental to our idea of how star formation proceeds, but it just doesn't seem to fit the data here."

Future telescopes such as NASA's upcoming James Webb Space Telescope will probe deeper into a protostar's formation process. Webb spectroscopic observations will observe the inner regions of disks surrounding protostars in infrared light, looking for jets in the youngest sources. Webb also will help astronomers measure the accretion rate of material from the disk onto the star, and study how the inner disk is interacting with the outflow.

Hubble Space Telescope (HST): https://www.nasa.gov/mission_pages/hubble/main/index.html

Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA, ESA, and N. Habel and S. T. Megeath (University of Toledo).

Greetings, Orbiter.ch

NASA Mega Moon Rocket Passes Key Test, Readies for Launch

 







NASA - Exploration Mission-1 patch.


March 18, 2021

The largest rocket element NASA has ever built, the core stage of NASA’s Space Launch System (SLS) rocket, fired its four RS-25 engines for 8 minutes and 19 seconds Thursday at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. The successful test, known as a hot fire, is a critical milestone ahead of the agency’s Artemis I mission, which will send an uncrewed Orion spacecraft on a test flight around the Moon and back to Earth, paving the way for future Artemis missions with astronauts.


Image above: The core stage for the first flight of NASA’s Space Launch System rocket is seen in the B-2 Test Stand during a second hot fire test, Thursday, March 18, 2021, at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. The four RS-25 engines fired for the full-duration of 8 minutes during the test and generated 1.6 million pounds of thrust. The hot fire test is the final stage of the Green Run test series, a comprehensive assessment of the Space Launch System’s core stage prior to launching the Artemis I mission to the Moon. Image Credits: NASA/Robert Markowitz.

Engineers designed the eight-part Green Run test campaign to gradually bring the SLS core stage to life for the first time, culminating with the hot fire. The team will use data from the tests to validate the core stage design for flight.

“The SLS is the most powerful rocket NASA has ever built, and during today’s test the core stage of the rocket generated more than 1.6 million pounds of thrust within seven seconds. The SLS is an incredible feat of engineering and the only rocket capable of powering America’s next-generation missions that will place the first woman and the next man on the Moon,” said acting NASA Administrator Steve Jurczyk. “Today’s successful hot fire test of the core stage for the SLS is an important milestone in NASA’s goal to return humans to the lunar surface – and beyond.”

NASA previously conducted a hot fire test of the SLS core stage Jan. 16. The four RS-25 engines fired together for the first time for about one minute before the test ended earlier than planned. Following data analysis, NASA determined a second, longer hot fire test would provide valuable data to help verify the core stage design for flight, while posing minimal risk to the Artemis I core stage.

SLS Core Stage Hot Fire Test

During the second hot fire test, the stage fired the engines for a little more than eight minutes, just like it will during every Artemis launch to the Moon. The longer duration hot fire tested a variety of operational conditions, including moving the four engines in specific patterns to direct thrust and powering the engines up to 109% power, throttling down and back up, as they will during flight.

“This longer hot fire test provided the wealth of data we needed to ensure the SLS core stage can power every SLS rocket successfully,” said John Honeycutt, manager for the SLS Program at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “During this test, the team conducted new operations with the core stage for the first time, repeated some critical operations, and recorded test data that will help us verify the core stage is ready for the first and future SLS flights for NASA’s Artemis program.”

The two propellant tanks in the SLS core stage collectively hold more than 733,000 gallons of supercold liquid hydrogen and liquid oxygen to help fuel the RS-25 engines at the bottom of the stage. The core stage has a complex network of flight software and avionics systems designed to help fly, track, and steer the rocket during launch and flight. Prior tests in the Green Run test series evaluated the integrated functionality and performance of the core stage’s avionics systems, propulsion systems, and hydraulic systems.

“Today is a great day for NASA, Stennis and this nation’s human space exploration program. This final test in the Green Run series represents a major milestone for this nation’s return to the Moon and eventual mission to Mars,” said Stennis Center Director Richard Gilbrech. “So many people across the agency and the nation contributed to this SLS core stage, but special recognition is due to the blended team of test operators, engineers, and support personnel for an exemplary effort in conducting the test today.”

NASA’s Space Launch System (SLS) description. Image Credit: NASA

Test teams at Stennis supervised a network of 114 tanker trucks and six propellant barges that provided liquid propellant through the B-2 Test Stand to the core stage. Test teams also delivered operational electrical power, supplied more than 330,000 gallons of water per minute to the stand’s flame deflector, and monitored structural interfaces of both the hardware and the stand.

Testing the SLS rocket’s core stage is a combined effort for NASA and its industry partners. Boeing is the prime contractor for the core stage and Aerojet Rocketdyne is the prime contractor for the RS-25 engines.

Next, the core stage for SLS will be refurbished, then shipped to NASA’s Kennedy Space Center in Florida. There, the core stage will be assembled with the solid rocket boosters and other parts of the rocket and NASA’s Orion spacecraft on the mobile launcher inside the Vehicle Assembly Building at Kennedy in preparation for Artemis I.

SLS, Orion, and the ground systems at Kennedy, along with the human landing system and the Gateway in orbit around the Moon, are NASA’s backbone for deep space exploration. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon on a single mission. The exploration of the Moon with NASA’s Artemis program includes preparations to send astronauts to Mars as part of America’s Moon to Mars exploration approach.

For more on NASA’s SLS, visit: https://www.nasa.gov/sls

Orion spacecraft: https://www.nasa.gov/exploration/systems/orion/index.html

For more on NASA’s SLS core stage Green Run test series, visit: https://www.nasa.gov/greenrun

Images (mentioned), Video, Text, Credits: NASA/Sean Potter/Kathryn Hambleton/Marshall Space Flight Center/Tracy McMahan/Stennis Space Center/Valerie Buckingham/NASA TV/SciNews.

Best regards, Orbiter.ch

Hubble Sees Changing Seasons on Saturn

 






NASA - Hubble Space Telescope patch.


March 18, 2021


NASA’s Hubble Space Telescope is giving astronomers a view of changes in Saturn’s vast and turbulent atmosphere as the planet’s northern hemisphere summer transitions to fall as shown in this series of images taken in 2018, 2019, and 2020 (left to right). Image Credits: NASA/ESA/STScI/A. Simon/R. Roth.

“These small year-to-year changes in Saturn’s color bands are fascinating,” said Amy Simon, planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.  “As Saturn moves towards fall in its northern hemisphere, we see the polar and equatorial regions changing, but we are also seeing that the atmosphere varies on much shorter timescales.” Simon is lead author of a paper on these observations published March 11 in Planetary Science Journal.

“What we found was a slight change from year-to-year in color, possibly cloud height, and winds - not surprising that the changes aren't huge, as we’re only looking at a small fraction of a Saturn year,” added Simon. “We expect big changes on a seasonal timescale, so this is showing the progression towards the next season.”


Animation above: Hubble Space Telescope images of Saturn taken in 2018, 2019, and 2020 as the planet’s northern hemisphere summer transitions to fall. Animation Credits: NASA/ESA/STScI/A. Simon/R. Roth.

The Hubble data show that from 2018 to 2020 the equator got 5 to 10 percent brighter, and the winds changed slightly. In 2018, winds measured near the equator were about 1,000 miles per hour (roughly 1,600 kilometers per hour), higher than those measured by NASA’s Cassini spacecraft during 2004-2009, when they were about 800 miles per hour (roughly 1,300 kilometers per hour). In 2019 and 2020 they decreased back to the Cassini speeds. Saturn’s winds also vary with altitude, so the change in measured speeds could possibly mean the clouds in 2018 were around 37 miles (about 60 kilometers) deeper than those measured during the Cassini mission. Further observations are needed to tell which is happening.

Saturn is the sixth planet from our Sun and orbits at a distance of about 886 million miles (1.4 billion kilometers) from the Sun. It takes around 29 Earth years to orbit the Sun, making each season on Saturn more than seven Earth years long. Earth is tilted with respect to the Sun, which alters the amount of sunlight each hemisphere receives as our planet moves in its orbit. This variation in solar energy is what drives our seasonal changes. Saturn is tilted also, so as the seasons change on that distant world, the change in sunlight could be causing some of the observed atmospheric changes.

Like Jupiter, the solar system’s largest planet, Saturn is a “gas giant” made mostly of hydrogen and helium, although there may be a rocky core deep inside. Enormous storms, some almost as large as Earth, occasionally erupt from deep within the atmosphere. Since many of the planets discovered around other stars are gas giants as well, astronomers are eager to learn more about how gas giant atmospheres work.

Saturn is the second largest planet in the solar system, over 9 times wider than Earth, with more than 50 moons and a spectacular system of rings made primarily of water ice. Two of these moons, Titan and Enceladus, appear to have oceans beneath their icy crusts that might support life. Titan, Saturn’s largest moon, is the only moon in our solar system with a thick atmosphere, including clouds that rain liquid methane and other hydrocarbons on to the surface, forming rivers, lakes, and seas. This mix of chemicals is thought to be similar to that on Earth billions of years ago when life first emerged. NASA’s Dragonfly mission will fly over the surface of Titan, touching down in various locations to search for the primal building blocks of life.

Hubble Space Telescope (HST). Image Credit: NASA

The Saturn observations are part of Hubble’s Outer Planets Atmospheres Legacy (OPAL) program. “The OPAL program allows us to observe each of the outer planets with Hubble every year, enabling new discoveries and watching how each planet is changing over time,” said Simon, principal investigator for OPAL.

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 (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Related links:

NASA’s Cassini: https://www.nasa.gov/mission_pages/cassini/main/index.html

Outer Planets Atmospheres Legacy (OPAL): https://archive.stsci.edu/prepds/opal/

Hubble Space Telescope (HST): https://www.nasa.gov/mission_pages/hubble/main/index.html

Images (mentioned), Animation (mentioned), Text Credit: NASA/Bill Steigerwald.

Best regards, Orbiter.ch

Day Before Soyuz Relocation, Astronauts Continue Studies on Microgravity’s Influence

 






ISS - Expedition 64 Mission patch.


March 18, 2021

A day before Expedition 64 relocates the Soyuz MS-17 to another port on the International Space Station, the six-person crew continued studies on the effects of microgravity on humans, plants, and materials, along with a couple outreach events.

NASA astronaut Victor Glover took part in two media events, each accompanied by a different crewmate. First up, Glover and Kate Rubins spoke with Fox 11 “Good Day L.A.” about living and working aboard the space station. About two hours later, Glover joined Shannon Walker for an outreach event with U.S. Rep. Norma Torres of California, where they answered questions submitted by students.

International Space Station (ISS). Animation Credit: NASA

Glover teamed up again with Rubins for an eye ultrasound. Receiving guidance from the ground, Glover served as operator for Rubins’ examination. Spaceflight, especially for prolonged missions, can affect vision and eye health. These ongoing checks provide invaluable data for researchers and test the accuracy and functionality of the portable medical equipment station crews rely upon — tools that will prove even more critical as explorers venture farther from Earth.

Meanwhile, NASA astronaut Michael Hopkins continued closing out spacesuit tools and equipment used during the previous Saturday spacewalk he and Glover completed to service the orbiting laboratory’s cooling system and communications gear. The veteran astronaut also swapped out a crystal growth chamber in support of the Industrial Crystallization Facility (ICF). The ICF is used for growing crystals in space that are not possible on Earth — specimens large enough for commercial use. These crystals are not only interesting to look at, but integral to the research and development of new materials.

JAXA’s (Japan Aerospace Exploration Agency’s) astronaut, Soichi Noguchi, was engrossed in an investigation that studies fast-growing plants, called Asian Herb in Space. Future space travel, especially to destinations like Mars, will rely on plants for sustenance, traditional medicine, and flavor. This experiment will add to the growing body of research on plant growth, plus provide new information on the formation of aroma compounds in herbs.


Image above: Two Russian spacecraft are seen docked to the International Space Station as it orbited 269 miles above southern Argentina. At left is the Soyuz MS-17 crew ship that will soon undock from the Rassvet module and relocate to the Poisk module, making room for three new crew members due to launch April 9 aboard the Soyuz MS-18 crew ship. At right is the aft end of the Progress 77 cargo craft docked to the Pirs docking compartment. Image Credit: NASA.

Flight Engineer Sergey Kud-Sverchkov of Roscosmos cultured various types of cells with the Kaskad investigation, while his counterpart, Commander Sergey Ryzhikov, was focused on setup and preparation for the Soyuz relocation activity.

On Friday, March 19, viewers can watch the Soyuz MS-17 undock and take a spin in the orbital neighborhood, so to speak, and later reattach to the Poisk module, which will free up the Rassvet port for the docking of Soyuz MS-18. Live coverage of the maneuver on NASA Television, the NASA app, and the agency’s website will begin at 12:15 p.m. EDT. Undocking from Rassvet is anticipated at 12:38 p.m., with redocking at Poisk targeted for 1:07 p.m.

The new vehicle, MS-18, will embark to the station after a planned April 9 launch, carrying NASA’s Mark Vande Hei and Roscosmos’ Oleg Novitsky and Pyotr Dubrov.

Related links:

NASA Television: https://www.nasa.gov/live

Expedition 64: https://www.nasa.gov/mission_pages/station/expeditions/expedition64/index.html

Industrial Crystallization Facility (ICF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7858

Asian Herb in Space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2052

Kaskad: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html#id=618

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

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

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Catherine Williams.

Greetings, Orbiter.ch

Seismic ripples reveal size of Mars’s core

 






NASA - InSight Mission patch.


March 18, 2021

Mars becomes the first inner planet after Earth to have its core measured.


Image above: InSight snapped this dusty selfie in early 2019 after deploying its seismometer. Much more dust has now settled on its solar panels. Image Credits: NASA/JPL-Caltech.

Scientists have peered into the heart of Mars for the first time. NASA’s InSight spacecraft, sitting on the Martian surface with the aim of seeing deep inside the planet, has revealed the size of Mars’s core by listening to seismic energy ringing through the planet’s interior.

The measurement suggests that the radius of the Martian core is 1,810 to 1,860 kilometres, roughly half that of Earth’s. That’s larger than some previous estimates, meaning the core is less dense than had been predicted. The finding suggests the core must contain lighter elements, such as oxygen, in addition to the iron and sulfur that constitute much of its make-up. InSight scientists reported their measurements in several presentations this week at the virtual Lunar and Planetary Science Conference, based out of Houston, Texas.

Internal Models of Mars. Image Credits: SEIS/Mars InSight

Rocky planets such as Earth and Mars are divided into the fundamental layers of crust, mantle and core. Knowing the size of each of those layers is crucial to understanding how the planet formed and evolved. InSight’s measurements will help scientists to determine how Mars's dense, metal-rich core separated from the overlying rocky mantle as the planet cooled. The core is probably still molten from Mars’s fiery birth, some 4.5 billion years ago.

Compare and contrast

The only other rocky planetary bodies for which scientists have measured the core are Earth and the Moon. Adding Mars will allow researchers to compare and contrast how the Solar System’s planets evolved. Similar to Earth, Mars once had a strong magnetic field generated by liquid sloshing its core; but that magnetic field dropped dramatically over time, causing Mars's atmosphere to escape into space and the surface to become cold, barren, and much less hospitable to life than Earth's.

Simon Stähler, a seismologist at the Swiss Federal Institute of Technology in Zurich, reported the core findings in a pre-recorded 18 March presentation for the virtual conference. Stähler declined an interview request from Nature, saying the team intends to submit the work for publication in a peer-reviewed journal.

Image of the theorized terrestrial planet interiors courtesy NASA. Below images are also courtesy NASA and JPL.

The work builds on earlier findings from InSight that detected layers in the Martian crust. “Now we start to have that deep structure down to the core,” said geophysicist Philippe Lognonné in another pre-recorded talk. Lognonné, based at the Paris Institute of Earth Physics in France, heads InSight’s seismometer team.

The spacecraft, which cost nearly US$1 billion, landed on Mars in 2018 and is the first mission to study the red planet’s interior. The stationary lander sits near the Martian equator and listens for ‘marsquakes’, the Mars equivalent of earthquakes. So far, InSight has detected around 500 quakes, meaning the planet is less seismically active than Earth but more so than the Moon. Most marsquakes are very small, Lognonné said, but nearly 50 of them have been between magnitude 2 and 4 — strong enough to provide information on the planet’s interior.

Just as seismometers do on Earth, InSight measures the size of the Martian core by studying seismic waves that have bounced off the deep boundary between the mantle and the core. With information from enough of these deep-travelling waves, InSight scientists were able to calculate the depth of the core–mantle boundary and hence the size of the core. The seismic data also suggest that the upper mantle, which extends to around 700 to 800 kilometres below the surface, contains a zone of thickened material in which seismic energy travels more slowly.

In an effort to replicate the conditions inside planetary cores, other researchers have squeezed combinations of different chemical elements at high pressures and temperatures. InSight’s estimate of the Martian core density agrees with many of those laboratory-based estimates, says Edgar Steenstra, a geochemist at the Carnegie Institution for Science in Washington, DC.

Orbital extreme

InSight might be running out of time to make discoveries. Dust has been piling up on its 2-metre-wide solar panels, cutting down on the amount of power the spacecraft can generate. Mars is also moving towards the farthest point from the Sun in its orbit, which will further limit the craft’s opportunity to recharge.

“This is going to cause us to reduce our instrument usage over the next few months,” says Mark Panning, InSight’s project scientist at the Jet Propulsion Laboratory in Pasadena, California.

In January, the team already had to give up on its German-built ‘mole’, a thermal probe that was supposed to bury itself in the soil and measure heat flow, but which encountered problems with friction and couldn’t dig deep.

Drastic temperature changes on Mars that occur when day turns to night and vice versa, create noise in the signals that Insight's seismometer collects, as the tether connecting it to the lander lays exposed on the planet's surface. So InSight is now trying to bury the tether by scooping dirt onto it in an attempt to insulate it.

InSight detects marsquakes mostly at night, because daytime winds cause too much shaking and interfere with seismic signals. But the windy season at its landing site recently drew to an end. Team scientists are looking forward to new-found seismic quiet to catch as many marsquakes as they can before the mission has to end.

doi: https://doi.org/10.1038/d41586-021-00696-7

InSight Mars Lander: https://www.nasa.gov/mission_pages/insight/main/index.html

Images (mentioned), Text, Credits: Nature/Alexandra Witze.

Best regards, Orbiter.ch

Powerful stratospheric winds measured on Jupiter for the first time

 







ALMA - Atacama Large Millimeter/submillimeter Array logo.


March 18, 2021

Representation of stratospheric winds near Jupiter’s south pole

Using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, a team of astronomers have directly measured winds in Jupiter’s middle atmosphere for the first time. By analysing the aftermath of a comet collision from the 1990s, the researchers have revealed incredibly powerful winds, with speeds of up to 1450 kilometres an hour, near Jupiter’s poles. They could represent what the team have described as a “unique meteorological beast in our Solar System”.

Jupiter is famous for its distinctive red and white bands: swirling clouds of moving gas that astronomers traditionally use to track winds in Jupiter’s lower atmosphere. Astronomers have also seen, near Jupiter's poles, the vivid glows known as aurorae, which appear to be associated with strong winds in the planet’s upper atmosphere. But until now, researchers had never been able to directly measure wind patterns in between these two atmospheric layers, in the stratosphere.

Comet Shoemaker–Levy 9 impacting Jupiter in 1994

Measuring wind speeds in Jupiter’s stratosphere using cloud-tracking techniques is impossible because of the absence of clouds in this part of the atmosphere. However, astronomers were provided with an alternative measuring aid in the form of comet Shoemaker–Levy 9, which collided with the gas giant in spectacular fashion in 1994. This impact produced new molecules in Jupiter’s stratosphere, where they have been moving with the winds ever since.

A team of astronomers, led by Thibault Cavalié of the Laboratoire d'Astrophysique de Bordeaux in France, have now tracked one of these molecules — hydrogen cyanide — to directly measure stratospheric "jets" on Jupiter. Scientists use the word "jets" to refer to narrow bands of wind in the atmosphere, like Earth’s jet streams.

Sharpening up Jupiter

"The most spectacular result is the presence of strong jets, with speeds of up to 400 metres per second, which are located under the aurorae near the poles," says Cavalié. These wind speeds, equivalent to about 1450 kilometres an hour, are more than twice the maximum storm speeds reached in Jupiter’s Great Red Spot and over three times the wind speed measured on Earth’s strongest tornadoes.

"Our detection indicates that these jets could behave like a giant vortex with a diameter of up to four times that of Earth, and some 900 kilometres in height," explains co-author Bilal Benmahi, also of the Laboratoire d’Astrophysique de Bordeaux. "A vortex of this size would be a unique meteorological beast in our Solar System," Cavalié adds.

Powerful stratospheric winds near Jupiter’s south pole (animation)

Astronomers were aware of strong winds near Jupiter’s poles, but much higher up in the atmosphere, hundreds of kilometres above the focus area of the new study, which is published today in Astronomy & Astrophysics. Previous studies predicted that these upper-atmosphere winds would decrease in velocity and disappear well before reaching as deep as the stratosphere. "The new ALMA data tell us the contrary," says Cavalié, adding that finding these strong stratospheric winds near Jupiter’s poles was a "real surprise".

The team used 42 of ALMA’s 66 high-precision antennas, located in the Atacama Desert in northern Chile, to analyse the hydrogen cyanide molecules that have been moving around in Jupiter’s stratosphere since the impact of Shoemaker–Levy 9. The ALMA data allowed them to measure the Doppler shift — tiny changes in the frequency of the radiation emitted by the molecules — caused by the winds in this region of the planet. "By measuring this shift, we were able to deduce the speed of the winds much like one could deduce the speed of a passing train by the change in the frequency of the train whistle," explains study co-author Vincent Hue, a planetary scientist at the Southwest Research Institute in the US.

Animated view of Jupiter showing comet Shoemaker–Levy 9 impact sites

In addition to the surprising polar winds, the team also used ALMA to confirm the existence of strong stratospheric winds around the planet’s equator, by directly measuring their speed, also for the first time. The jets spotted in this part of the planet have average speeds of about 600 kilometres an hour.

The ALMA observations required to track stratospheric winds in both the poles and equator of Jupiter took less than 30 minutes of telescope time. "The high levels of detail we achieved in this short time really demonstrate the power of the ALMA observations," says Thomas Greathouse, a scientist at the Southwest Research Institute in the US and co-author of the study. "It is astounding to me to see the first direct measurement of these winds."

"These ALMA results open a new window for the study of Jupiter’s auroral regions, which was really unexpected just a few months back," says Cavalié. "They also set the stage for similar yet more extensive measurements to be made by the JUICE mission and its Submillimetre Wave Instrument," Greathouse adds, referring to the European Space Agency’s JUpiter ICy moons Explorer, which is expected to launch into space next year.

ESO’s ground-based Extremely Large Telescope (ELT), set to see first light later this decade, will also explore Jupiter. The telescope will be capable of making highly detailed observations of the planet’s aurorae, giving us further insight into Jupiter’s atmosphere.

More information

This research is presented in the paper "First direct measurement of auroral and equatorial jets in the stratosphere of Jupiter" published today in Astronomy & Astrophysics (doi:10.1051/0004-6361/202140330).

https://www.aanda.org/10.1051/0004-6361/202140330

The team is composed of T. Cavalié (Laboratoire d’Astrophysique de Bordeaux [LAB], France, and LESIA, Observatoire de Paris, PSL Research University [LESIA], France), B. Benmahi (LAB), V. Hue (Southwest Research Institute [SwRI], USA), R. Moreno (LESIA), E. Lellouch (LESIA), T. Fouchet (LESIA), P. Hartogh (Max-Planck-Institut für Sonnensystemforschung [MPS], Germany), L. Rezac (MPS), T. K. Greathouse (SwRI), G. R. Gladstone (SwRI), J. A. Sinclair (Jet Propulsion Laboratory, California Institute of Technology, USA), M. Dobrijevic (LAB), F. Billebaud (LAB) and C. Jarchow (MPS).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a Strategic Partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Related article:

NASA’s Juno Reveals Dark Origins of One of Jupiter’s Grand Light Shows
https://orbiterchspacenews.blogspot.com/2021/03/nasas-juno-reveals-dark-origins-of-one.html

Links:

Research paper: https://www.eso.org/public/archives/releases/sciencepapers/eso2104/eso2104a.pdf

Images of ALMA: https://www.eso.org/public/images/archive/category/alma/

For scientists: got a story? Pitch your research: http://eso.org/sci/publications/announcements/sciann17277.html

Atacama Large Millimeter/submillimeter Array (ALMA): http://www.eso.org/public/teles-instr/alma/

European Southern Observatory (ESO): https://www.eso.org/public/

Text: ESO/Bárbara Ferreira/Suzanna Randall/Southwest Research Institute/Thomas Greathouse/Vincent Hue/Laboratoire d'Astrophysique de Bordeaux/Bilal Benmahi/Thibault Cavalié/Images: ESO/L. Calçada & NASA/JPL-Caltech/SwRI/MSSS/ESO/F. Marchis, M. Wong, E. Marchetti, P. Amico, S. Tordo/Videos: ESO/L. Calçada & NASA/JPL-Caltech/SwRI/MSSS/ESO/M. Kornmesser, NASA/ESA.

Greetings, Orbiter.ch

Another First: Perseverance Captures the Sounds of Driving on Mars

 







NASA - Mars 2020 Perseverance Rover logo.


March 18, 2021

NASA’s newest rover recorded audio of itself crunching over the surface of the Red Planet, adding a whole new dimension to Mars exploration.


Image above: NASA’s Mars Perseverance rover acquired this image using its onboard left Navigation Camera (Navcam). The camera is located high on the rover’s mast and aids in driving. This image was acquired on Mar. 7, 2021 (Sol 16). Image Credits: NASA/JPL-Caltech.

As the Perseverance rover began to make tracks on the surface of Mars, a sensitive microphone it carries scored a first: the bangs, pings, and rattles of the robot’s six wheels as they rolled over Martian terrain.

“A lot of people, when they see the images, don’t appreciate that the wheels are metal,” said Vandi Verma, a senior engineer and rover driver at NASA’s Jet Propulsion Laboratory in Southern California. “When you’re driving with these wheels on rocks, it’s actually very noisy.”

More than 16 minutes of sounds from Perseverance’s 90-foot (27.3-meter) drive on March 7 were captured by Perseverance’s entry, descent, and landing (EDL) microphone, which remains operational on the rover after its historic touchdown on Feb. 18. The off-the-shelf microphone was added to the rover to help take the public along for the ride during touchdown, but mission members have been eager to hear the sounds from the surface, too.

“If I heard these sounds driving my car, I’d pull over and call for a tow,” said Dave Gruel, lead engineer for Mars 2020’s EDL Camera and Microphone subsystem. “But if you take a minute to consider what you’re hearing and where it was recorded, it makes perfect sense.”

Two versions of the audio clip of the same drive were released to the public on March 17. The first version features over 16 minutes of raw, unfiltered sounds of the rover traveling in Jezero Crater. In it, the noise generated by the interaction of Perseverance’s mobility system (its wheels and suspension) with the surface can be heard, along with a high-pitched scratching noise. Perseverance’s engineering team continues to evaluate the source of the scratching noise, which may either be electromagnetic interference from one of the rover’s electronics boxes or interactions between the mobility system and the Martian surface. The EDL microphone was not intended for surface operations and had limited testing in this configuration before launch.

Sounds of Perseverance Mars Rover Driving – Sol 16

Video above: unfiltered sounds of the Perseverance Mars rover traveling in Jezero Crater. The noise generated by the interaction of the rover’s wheels and suspension with the surface can be heard, along with a high-pitched scratching noise. Perseverance’s engineering team continues to evaluate the source of the scratching noise, which may either be electromagnetic interference from one of the rover’s electronics boxes or interactions between the rover mobility system and the Martian surface. The entry, descent, and landing microphone was not intended for surface operations and had limited testing in this configuration before launch. Video Credits: NASA/JPL-Caltech.

This first audio of a drive across the Martian surface joins a growing playlist of Mars sounds beamed back to Earth from Perseverance. A second microphone, part of the rover’s SuperCam instrument, previously picked up the sighing of Martian wind and the rapid ticking sound of the instrument’s laser zapping rocks to reveal details of their structure and composition. Such information will help scientists as they search Jezero Crater for signs of ancient microscopic life, taking samples of rock and sediment to be returned to Earth by future missions.

The SuperCam sounds were part of a series of systems checks the rover has gone through, ranging from the unstowing of Perseverance’s massive robotic arm to making its first weather observations using the Mars Environmental Dynamics Analyzer.

Perseverance Mars Rover Driving. Animation Credits: NASA/JPL

The rover has also been searching for a suitable airfield for the Ingenuity Mars Helicopter to attempt its first flight tests. Now that the right spot has been found, the Perseverance and Ingenuity teams are making plans for the rover to deploy the helicopter, which will have 30 Martian days, or sols (31 Earth days), to complete up to five test flights.

And then the hunt for ancient life will begin in earnest, with Perseverance exploring terrain once thought to be covered with water. Between the rover’s 19 cameras and its two microphones, the experience will be packed with sights and sounds. For Verma, who has helped “drive” NASA’s last four Mars rovers, planning their routes and transmitting instructions so they can take a day’s drive across uncharted terrain, the audio is more than just cool.

“The variations between Earth and Mars – we have a feeling for that visually,” she said. “But sound is a whole different dimension: to see the differences between Earth and Mars, and experience that environment more closely.”

More About the Mission

A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.

Related article:

Mars Perseverance Rover Provides First Audio Recording of Red Planet
https://orbiterchspacenews.blogspot.com/2021/02/mars-perseverance-rover-provides-first.html

For more about Perseverance:

https://mars.nasa.gov/mars2020/

https://nasa.gov/perseverance

Image (mentioned), Video (mentioned), Animation (mentioned), Text, Credits: NASA/Grey Hautaluoma/Joshua Handal/JPL/DC Agle.

Best regards, Orbiter.ch

Galileo will help Lunar Pathfinder navigate around Moon

 







ESA - Galileo Mission patch.


March 18, 2021

ESA’s Lunar Pathfinder mission to the Moon will carry an advanced satellite navigation receiver, in order to perform the first ever satnav positioning fix in lunar orbit. This experimental payload marks a preliminary step in an ambitious ESA plan to expand reliable satnav coverage – as well as communication links – to explorers around and ultimately on the Moon during this decade.

Due for launch by the end of 2023 into lunar orbit, the public-private Lunar Pathfinder comsat will offer commercial data relay services to lunar missions – while also stretching the operational limits of satnav signals.

Galileo constellation

Navigation satellites like Europe’s Galileo constellation are intended to deliver positioning, navigation and timing services to our planet, so most of the energy of their navigation antennas radiates directly towards the Earth disc, blocking its use for users further away in space.

“But this is not the whole story," explains Javier Ventura-Traveset, leading ESA’s Galileo Navigation Science Office and coordinating ESA lunar navigation activities. "Navigation signal patterns also radiate sideways, like light from a flashlight, and past testing shows these antenna ‘side lobes’ can be employed for positioning, provided adequate receivers are implemented.”

Galileo 'side lobe' signals

Just like people or cars on the ground, satellites in low-Earth orbit rely heavily on satnav signals to determine their orbital position, and since ESA proved higher-orbit positioning was possible, a growing number of satellites in geostationary orbit today employ satnav receivers.

But geostationary orbit is 35 786 km up, while the Moon is more than ten times further away, at an average distance of 384 000 km. In 2019 however, NASA’s Magnetospheric Multiscale Mission acquired GPS signals to perform a fix and determine its orbit from 187 166 km away, close to halfway the Earth-Moon distance.

Javier adds: "This successful experimental evidence provides us high confidence since the receiver we will embark on Lunar Pathfinder will have a significantly improved sensitivity, employ both Galileo and GPS signals and will also feature a high-gain satnav antenna.”

Lunar Pathfinder will relay signals from other Moon missions

This high sensitivity receiver’s main antenna was developed through ESA’s General Support Technology Programme, with the receiver’s main unit developed through ESA’s Navigation Innovation and Support Programme, NAVISP.

The receiver project is led by ESA navigation engineer Pietro Giordano: “The high sensitivity receiver will be able to detect very faint signals, millions of times weaker than the ones received on Earth. The use of advanced on-board orbital filters will allow to achieve unprecedented orbit determination accuracy on an autonomous basis.”

Lunar Pathfinder’s receiver is projected to achieve positioning accuracy of around 100 m – more accurate than traditional ground tracking.

Lunar orbits represent a challenge

The availability of satnav will allow the performance of ‘Precise Orbit Determination’ for lunar satellites, notes Werner Enderle, Head of ESA’s Navigation Support Office: “Traditional orbit determination for lunar orbiting satellites is performed by radio ranging, using deep space ground stations. This Lunar Pathfinder demonstration will be a major milestone in lunar navigation, changing the entire approach. It will not only increase spacecraft autonomy and sharpen the accuracy of results, it will also help to reduce operational costs.”  

While lunar orbits are often unstable, with low-orbiting satellites drawn off course by the lumpy mass concentrations or ‘mascons’ making up the Moon , Lunar Pathfinder is planned to adopt a highly-stable ‘frozen’ elliptical orbit, focused on the lunar south pole – a leading target for future expeditions.

Lunar Pathfinder will focus coverage on the Moon's south pole

Earth – and its satnav constellations – should remain in view of Lunar Pathfinder for the majority of testing. The main challlenge will be overcoming the limited geometry of satnav signals all coming from the same part of the sky, along with the low signal power.

Lunar Pathfinder's demonstration that terrestrial satnav signals can be employed to navigate in lunar orbits will be an important early step in ESA’s Moonlight initiative. Supported through three ESA Directorates, Moonlight will go on to establish a Lunar Communication and Navigation Service.

Moonlight: connecting Earth with the Moon

“Over this coming decade, ESA aims to contribute to building up a common communications and navigation infrastructure for all lunar missions based on dedicated lunar satellites,” explains Bernhard Hufenbach, managing commercialisation and innovation initiatives for space exploration at ESA.

“Moonlight will allow to support missions that cannot use Earth satnav signals, such as landers on the far side and is planning to cover the current gap towards the needs expressed by the Global Exploration community, targeting positioning accuracy below 50 metres.”

Extending satnav to the Moon

As well as facilitating lunar exploration, these satnav signals might one day become a tool for science in their own right, used, for example, to perform reflectometry across the lunar surface; sounding the scant dusty ‘exosphere’ that surrounds the Moon or by providing a common time reference signal across the Moon, to be used for fundamental physics or astronomy experiments.

So as well as marking a first in the history of satellite navigation, Javier notes that Lunar Pathfinder’s satnav experiment will have larger consequences: “This will become the first ever demonstration of GPS and Galileo reception in lunar orbit, opening the door to a complete way to navigate spacecraft in deep space, enabling human exploration of the Moon.”

Related links:

Lunar Pathfinder: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/A_pathway_for_communicating_at_the_Moon

NASA’s Magnetospheric Multiscale Mission (MMS): https://www.esa.int/%20https://www.nasa.gov/mission_pages/mms/overview/index.html

ESA’s General Support Technology Programme: https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Shaping_the_Future/About_the_General_Support_Technology_Programme_GSTP

ESA’s Navigation Innovation and Support Programme (NAVISP): https://navisp.esa.int/

ESA’s Moonlight initiative: https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Lunar_satellites

Images, Video, Text, Credits: ESA/P. Carril/SSTL/JAXA/NHK.

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