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November 6, 2017November 7, 2017 by Matt Williams

New Study Says Enceladus has had an Internal Ocean for Billions of Years

Cutaway showing the interior of Saturn's moon Enceladus. Credit: ESA

When the Cassini mission arrived in the Saturn system in 2004, it discovered something rather unexpected in Enceladus’ southern hemisphere. From hundreds of fissures located in the polar region, plumes of water and organic molecules were spotted periodically spewing forth. This was the first indication that Saturn’s moon may have an interior ocean caused by hydrothermal activity near the core-mantle boundary.

According to a new study based on Cassini data, which it obtained before diving into Saturn’s atmosphere on September 15th, this activity may have been going on for some time. In fact, the study team concluded that if the moon’s core is porous enough, it could have generated enough heat to maintain an interior ocean for billions of years. This study is the most encouraging indication yet that the interior of Enceladus could support life.

The study, titled “Powering prolonged hydrothermal activity inside Enceladus“, recently appeared in the journal Nature Astronomy. The study was led by Gaël Choblet, a researcher with the Planetary and Geodynamic Laboratory at the University of Nantes, and included members from NASA’s Jet Propulsion Laboratory, Charles University, and the Institute of Earth Sciences and the Geo- and Cosmochemistry Laboratory at the University of Heidelberg.

*Artist’s rendering of possible hydrothermal activity that may be taking place on and under the seafloor of Enceladus. Credit: NASA/JPL*

Prior to the Cassini mission’s many flybys of Enceladus, scientists believed this moon’s surface was composed of solid ice. It was only after noticing the plume activity that they came to realize that it had water jets that extended all the way down to a warm-water ocean in its interior. From the data obtained by Cassini, scientists were even able to make educated guesses of where this internal ocean lay.

All told, Enceladus is a relatively small moon, measuring some 500 km (311 mi) in diameter. Based on gravity measurements performed by Cassini, its interior ocean is believed to lie beneath an icy outer surface at depths of 20 to 25 km (12.4 to 15.5 mi). However, this surface ice thins to about 1 to 5 km (0.6 to 3.1 mi) over the southern polar region, where the jets of water and icy particles jet through fissures.

Based on the way Enceladus orbits Saturn with a certain wobble (aka. libration), scientists have been able to make estimates of the ocean’s depth, which they place at 26 to 31 km (16 to 19 mi). All of this surrounds a core which is believed to be composed of silicate minerals and metal, but which is also porous. Despite all these findings, the source of the interior heat has remained something of an open question.

This mechanism would have to be active when the moon formed billions of years ago and is still active today (as evidenced by the current plume activity). As Dr. Choblet explained in an ESA press statement:

“Where Enceladus gets the sustained power to remain active has always been a bit of mystery, but we’ve now considered in greater detail how the structure and composition of the moon’s rocky core could play a key role in generating the necessary energy.”

Gravity measurements by NASA’s Cassini spacecraft and Deep Space Network suggest that Saturn’s moon Enceladus, which has jets of water vapor and ice gushing from its south pole, also harbors a large interior ocean beneath an ice shell, as this illustration depicts. Credit: NASA/JPL-Caltech

For years, scientists have speculated that tidal forces caused by Saturn’s gravitational influence are responsible for Enceladus’ internal heating. The way Saturn pushes and pulls the moon as it follows an elliptical path around the planet is also believed to be what causes Enceladus’ icy shell to deform, causing the fissures around the southern polar region. These same mechanisms are believed to be what is responsible for Europa’s interior warm-water ocean.

However, the energy produced by tidal friction in the ice is too weak to counterbalance the heat loss seen from the ocean. At the rate Enceladus’ ocean is losing energy to space, the entire moon would freeze solid within 30 million years. Similarly, the natural decay of radioactive elements within the core (which has been suggested for other moons as well) is also about 100 times too weak to explain Enceladus interior and plume activity.

To address this, Dr. Choblet and his team conducted simulations of Enceladus’ core to determine what kind of conditions could allow for tidal heating over billions of years. As they state in their study:

“In absence of direct constraints on the mechanical properties of Enceladus’ core, we consider a wide range of parameters to characterize the rate of tidal friction and the efficiency of water transport by porous flow. The unconsolidated core of Enceladus can be viewed as a highly granular/fragmented material, in which tidal deformation is likely to be associated with intergranular friction during fragment rearrangements.”

Artist rendering showing an interior cross-section of the crust of Enceladus, which shows how hydrothermal activity may be causing the plumes of water at the moon’s surface.Credits: NASA-GSFC/SVS, NASA/JPL-Caltech/Southwest Research Institute

What they found was that in order for the Cassini observations to be borne out, Enceladus’ core would need to be made of unconsolidated, easily deformable, porous rock. This core could be easily permeated by liquid water, which would seep into the core and gradually heated through tidal friction between sliding rock fragments. Once this water was sufficiently heated, it would rise upwards because of temperature differences with its surroundings.

This process ultimately transfers heat to the interior ocean in narrow plumes which rise to the meet Enceladus’ icy shell. Once there, it causes the surface ice to melt and forming fissures through which jets reach into space, spewing water, ice particles and hydrated minerals that replenish Saturn’s E-Ring. All of this is consistent with the observations made by Cassini, and is sustainable from a geophysical point of view.

In other words, this study is able to show that action in Enceladus’ core could produce the necessary heating to maintain a global ocean and produce plume activity. Since this action is a result of the core’s structure and tidal interaction with Saturn, it is perfectly logical that it has been taking place for billions of years. So beyond providing the first coherent explanation for Enceladus’ plume activity, this study is also a strong indication of habitability.

As scientists have come to understand, life takes a long time to get going. On Earth, it is estimated that the first microorganisms arose after 500 million years, and hydrothermal vents are believed to have played a key role in that process. It took another 2.5 billion years for the first multi-cellular life to evolve, and land-based plants and animals have only been around for the past 500 million years.

Knowing that moons like Enceladus – which has the necessary chemistry to support for life – has also had the necessary energy for billions of years is therefore very encouraging. One can only imagine what we will find once future missions begin inspecting its plumes more closely!

Further Reading: ESA, Nature Astronomy

September 30, 2017October 1, 2017 by Ken Kremer

NASA’s Webb Space Telescope Launch Delayed to 2019

The 18-segment gold coated primary mirror of NASA’s James Webb Space Telescope is raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on Nov. 2, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com

The most powerful space telescope ever built will have to wait on the ground for a few more months into 2019 before launching to the High Frontier and looking back nearly to the beginning of time and unraveling untold astronomical secrets on how the early Universe evolved – Engineers need a bit more time to complete the Webb telescopes incredibly complex assembly and testing here on Earth.

Blastoff of NASA’s mammoth James Webb Space Telescope (JWST) has been postponed from late 2018 to the spring of 2019.

“NASA’s James Webb Space Telescope now is planning to launch between March and June 2019 from French Guiana, following a schedule assessment of the remaining integration and test activities,” the agency announced.

Until now the Webb telescope was scheduled to launch on a European Space Agency (ESA) Ariane V booster from the Guiana Space Center in Kourou, French Guiana in October 2018.

“The change in launch timing is not indicative of hardware or technical performance concerns,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at Headquarters in Washington, in a statement.

“Rather, the integration of the various spacecraft elements is taking longer than expected.”

NASA’s says the currently approved budget will not bust the budget or reduce the science output. It “accommodates the change in launch date, and the change will not affect planned science observations.”

NASA’s $8.8 Billion James Webb Space Telescope is the most powerful space telescope ever built and is the scientific successor to the phenomenally successful Hubble Space Telescope (HST).

The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

Up close side-view of newly exposed gold coated primary mirrors installed onto mirror backplane holding structure of NASA’s James Webb Space Telescope inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. Aft optics subsystem stands upright at center of 18 mirror segments between stowed secondary mirror mount booms. Credit: Ken Kremer/kenkremer.com

Since Webb is not designed to be serviced by astronauts, the extremely thorny telescope deployment process is designed to occur on its own over a period of several months and must be fully successful. Webb will be positioned at the L2 Lagrange point- a gravitationally stable spot approximately 930,000 miles (1.5 million km) away from Earth.

So its better to be safe than sorry and take the extra time needed to insure success of the hugely expensive project.

NASA’s James Webb Space Telescope sits in Chamber A at NASA’s Johnson Space Center in Houston awaiting the colossal door to close in July 2017 for cryogenic testing. Credits: NASA/Chris Gunn

Various completed components of the Webb telescope are undergoing final testing around the country to confirm their suitability for launch.

Critical cryogenic cooling testing of Webb’s mirrors and science instrument bus is proceeding well inside a giant chamber at NASA’s Johnson Space Center in Texas.

However integration and testing of the complex multilayered sunshield at Northrup Grumman’s Redondo Beach, Ca. facility is taking longer than expected and “has experienced delays.”

The tennis court sized sunshield will protect the delicate optics and state of the art infrared science instruments on NASA’s Webb Telescope.

Webb’s four research instruments cannot function without the essential cooling provided by the sunshield deployment to maintain them at an operating temperature of minus 388 degrees F (minus 233 degrees C).

The Webb telescopes groundbreaking sunshield subsystem consists of five layers of kapton that will keep the optics and instruments incredibly cool, by reducing the incoming sunside facing temperature more than 570 degrees Fahrenheit. Each layer is as thin as a human hair.

All 5 layers of the Webb telescope sunshield installed at Northrop Grumman’s clean room in Redondo Beach, California. The five sunshield membrane layers are each as thin as a human hair. Credits: Northrop Grumman Corp.

“Webb’s spacecraft and sunshield are larger and more complex than most spacecraft. The combination of some integration activities taking longer than initially planned, such as the installation of more than 100 sunshield membrane release devices, factoring in lessons learned from earlier testing, like longer time spans for vibration testing, has meant the integration and testing process is just taking longer,” said Eric Smith, program director for the James Webb Space Telescope at NASA Headquarters in Washington, in a statement.

“Considering the investment NASA has made, and the good performance to date, we want to proceed very systematically through these tests to be ready for a Spring 2019 launch.”

Artist’s concept of the James Webb Space Telescope (JWST) with Sunshield at bottom. Credit: NASA/ESA

Northrop Grumman designed the Webb telescope’s optics and spacecraft bus for NASA’s Goddard Space Flight Center in Greenbelt, Maryland, which manages Webb.

Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about the upcoming ULA Atlas NRO NROL-52 spysat launch on Oct 5 and SpaceX Falcon 9 SES-11 launch on Oct 7, JWST, OSIRIS-REx, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Oct 3-6, 8: “ULA Atlas NRO NROL-52 spysat launch, SpaceX SES-11, CRS-12 resupply launches to the ISS, Intelsat35e, BulgariaSat 1 and NRO Spysat, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, ULA Atlas/John Glenn Cygnus launch to ISS, SBIRS GEO 3 launch, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

September 26, 2017 by Matt Williams

Newly Discovered Star Cluster Analyzed by Gaia Probe

Gaia mapping the stars of the Milky Way. Credit: ESA/ATG medialab; background: ESO/S. Brunier

In 2013, the European Space Agency (ESA) deployed the Gaia mission, a space observatory designed to measure the positions of movements of celestial bodies. For the past four years, Gaia has been studying distant stars, planets, comets, asteroids, quasars and other astronomical objects, and the data it has acquired will be used to construct the largest and most precise 3D space catalog ever made, totaling 1 billion objects.

Using data provided by Gaia, a team of international scientists conducted a study of the recently-discovered star cluster known as Gaia 1. Located about 15,000 light years from Earth and measuring some 29 light years in radius, much about this cluster has remained unknown. As such, this study helped place constraints on a number of mysteries of this star cluster, which include its age, metallicity and origin.

For the sake of their study, which recently appeared in the journal Astronomy and Astrophysics under the title “Detailed Chemical Abundance Analysis of the Thick Disk Star Cluster Gaia 1“, the team conducted a detailed chemical abundance study of Gaia 1 to determine its unknown parameters. From this, accurate estimates on its age and composition are likely to now be possible.

*Sky map based on the first release of Gaia data (DR1). Credit: ESA/Gaia/DPAC/A. Moitinho & M. Barros, CENTRA – University of Lisbon.*

This star cluster was first identified in May 2017, thanks to first data release – aka. Data Release 1 (DR1) – from the ESA. Based on photometry provided by Gaia, the Two Micron All-Sky Survey (2MASS), the Wide-field Infrared Survey Explorer (WISE), and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) – the object was characterized as being an intermediate-age (6.3 billion years) and moderately metal-rich system.

This combined photometry also indicated that the cluster had a radius of about 29 light years and contained as much as 20,000 Solar Masses. However, further studies found that the cluster was actually far more metal-rich than previously thought. This indicated that Gaia 1 was likely to be significantly younger, with estimates now claiming that it was at least 3 billion years old.

In addition, these subsequent studies also raised the possibility that the cluster was extra-galactic in origin, based on the fact that it orbits about 5,500 light years (~1.7 kpc) above the Milky Way’s disk. To remedy this, the team – led by Andreas Koch of the University of Lancaster and the Center for Astronomy Heidelberg – used Gaia data in order to conduct a detailed study of just how metal-rich the cluster was to get a better idea of its age.

As they stated in their study: “[T]his work focuses on a detailed chemical abundance analysis of four red giant members of Gaia 1, based on high-resolution spectroscopy, which we complement by an investigation of the orbital properties of this transition object.” This consisted of measuring the abundances of 14 elements within these red giant stars, which were selected from the 2MASS survey.

What they determined was that the Gaia 1 was more metal poor than previously expected, which indicated that it is older than the revised age estimates indicated – between 3 billion and 5.3 billion years old. In addition, they also measured the proper motions and orbits of the four target stars, using data obtained from the fifth U.S. Naval Observatory CCD Astrograph Catalog (UCAC5).

This information revealed that in the course of their orbits, the four target stars would reach a maximum distance of 3,262 light years (1.0 kpc) above the galactic disk, which was an indication that they were not extra-galactic in origin. Last, but not least, they indicated that Gaia 1’s structure does not truly conform to that of a globular cluster, as it was originally designated. As they conclude in their study:

“This confirms that Gaia 1 is rather a massive and luminous open cluster than a low-mass globular cluster. Finally, orbital computations of the target stars bolster our chemical findings of Gaia 1’s present-day membership with the thick disk, even though it remains unclear, which mechanisms put it in that place.”

While this study has helped place constraints on one of a newly-discovered Gaia object, the team acknowledges that there is still much to be discovered about this star cluster. They also acknowledge that there is a margin of error when it comes to their study, and that further research is needed before Gaia 1 can be properly classified.

*The band of light (the Milky Way) that is visible in the night sky, showing the stellar disk of our galaxy. Credit: Bob King*

“However, the hint of a metallicity spread between different studies in the literature may point towards a more complex origin that could involve a once more massive progenitor,” they state. “Thus the question as to its exact formation and origin remains unclear and needs to await more data such as the precise and accurate parallaxes that Gaia can offer.”

This newly-discovered cluster, and all attempts to better understand it, are merely the tip of the iceberg when it comes to what the Gaia mission has revealed so far. The second official release of Gaia data – aka. Gaia DR2 – is scheduled to take place in April of 2018. This will be followed by a third release in 2020 and, barring any mission extensions, a fourth and final release in 2022.

Further Reading: Astronomy and Astrophysics

September 22, 2017September 22, 2017 by Matt Williams

Scientists Urge Europe to Stick With “Armageddon”-style Asteroid Mission

A computer generated handout image released by the European Space Agency shows the impact of the DART (Double Asteroid Redirection Test) projectile on the binary asteroid system (65803) Didymos. Credit: ESA/AFP

For decades, scientists have known that in near-Earth space there are thousands of comets and asteroids that periodically cross Earth’s orbit. These Near-Earth Objects (NEOs) are routinely tracked by NASA’s Center for Near Earth Object Studies (CNEOS) to make sure that none pose a risk of collision with our planet. Various programs and missions have also been proposed to divert or destroy any asteroids that might pass too closely to Earth in the future.

One such mission is the Asteroid Impact & Deflection Assessment (AIDA), a collaborative effort between NASA and the European Space Agency (ESA). Recently, the ESA announced that it would be withdrawing from this mission due to budget constraints. But this past Wednesday (Sept. 20th), during the European Planetary Science Conference in Riga, a group of international scientists urged them to reconsider.

In addition to NASA and the ESA, AIDA was designed with assistance from the Observatoire de la Côte d´Azur (OCA), and the Johns Hopkins University Applied Physics Laboratory (JHUAPL). To test possible asteroid deflection techniques, the mission intends to send a spacecraft to crash into the tiny moon of the distant asteroid named Didymos (nicknamed “Didymoon”) by 2022 to alter its trajectory.

*Artist’s impression of the path DART will take to reach the asteroid Didymos. Credit: NASA*

This mission would be a first for scientists, and would test the capabilities of space agencies to divert rocks away from Earth’s orbit. NASA’s contribution to this mission is known as the Double Asteroid Redirection Test (DART), the spacecraft which would be responsible for crashing into Didymoon. Plans for this spacecraft recently entered Phase B, having met with approval, but still in need of further development.

The plan was to mount DART on an already planned commercial or military launch, and would then be placed in geosynchronous orbit between December 2020 and May 2021. It would then rely on a NEXT-C ion engine to push itself beyond the Moon and reach an escape point to depart the Earth-Moon system, eventually making its way to Didymos and Didymoon.

Europe’s contribution to the mission was known as the Asteroid Impact Mission (AIM), which would involve sending a small craft close to Didymos to observe the crash and conduct research on the asteroid’s moon. Unfortunately, this aspect of the mission suffered a setback when space ministers from the ESA’s 22 member states rejected a €250 million ($300 million USD) request for funding last December.

However, during the European Planetary Science Congress – which will be taking place from September 17th to 22nd in the Latvian capital of Riga – scientists took the opportunity to advise the mission’s European partners to get back on board. As they emphasized, this mission – which is a dry-run for future asteroid redirect missions – is crucial if space agencies hope to develop the capacity to protect Earth from hazardous NEOs.

ESA’s Asteroid Impact Mission, a candidate mission due for launch in 2020, will map the smaller body of the Didymos binary asteroid system down to 1 m resolution following its arrival in 2022. Credit: ESA

Andrew Cheng from JHUAPL is the project scientist for the DART mission. As he told the AFP at the European Planetary Science Congress, “This is the kind of disaster that could be a tremendous catastrophe.” He also stressed that unlike other natural disasters, an asteroid strike “is something that the world is able to defend. We can do something.”

But before that can happen, the methods need to be further developed, tested and refined. Hence why Didymoon was selected as the target for the AIDA mission. Whereas the meteor that exploded over the Russian town of Chelyabinsk in 2013 was just 20 meters across (65 feet), but still injured 1600 people, Didymoon measures about 160 meters (525 feet) in diameter.

It is estimated that if this asteroid struck Earth, the resulting impact would be as powerful as a 400 megatonne blast. To put that in perspective, the most powerful thermonuclear device ever built – the Soviet Tsar Bomba – had a yield of 50 megatonnes. Hence, the smaller companion of this binary asteroid, if it struck Earth, would have an impact 80 times greater than the most powerful bomb ever built by humans.

In addition to advocating that the ESA remain committed to the mission, European scientists at the conference also proposed an altered, more cost-effective alternative for AIM. This alternative called for a miniaturized version of the AIM craft that would be equipped with just a camera, forgoing a lander and radars designed to probe Didymoon’s internal structure.

*Simulated image of the Didymos system, derived from photometric lightcurve and radar data. Credits: Naidu et al./AIDA Workshop (2016)*

According to Patrick Michel, the science lead for the AIM mission, this revised mission would cost about €210 million ($250 million USD). But as he also noted, this would require that the AIM part of the mission be delayed. While it would still conduct crucial measurements of Didymoon, it would not be part of the AIDA mission if NASA decides to stick with its original timeline.

“The main point of the mission was to measure the mass of the object, because this is how you really measure the deflection,” he said. “Two or three years (after impact), these things won’t change. Of course it’s better… that we have the two at the same time. But we found something I think that still works and allows to relax the very tight schedule.”

In the meantime, Jan Woerner – the head of the European Space Agency – indicated that the ESA would be moving forward with the new proposal when the next ministerial meeting takes place in 2019. As he told the AFP via email:

“It is important for humanity, as a species we have the means today to deflect an asteroid. We know it will happen, one day sooner or later. It’s not a question of if, but when. We have never tested asteroid deflection and there is no way we can test in (the) laboratory. We need to know if our models are correct, (whether) our simulations work as expected.”

In the end, it remains to be seen if the AIDA mission will see one or two missions traveling to Didymoon by 2022. Obviously, it would be better if both mission happened simultaneously, as the AIM mission will be capable of obtaining information DART will not. Much of that information has to do with with studying the effects of the collision up close and as they happen.

But regardless of how this mission unfolds, it is clear that space agencies from around the world are dedicated to developing techniques for protecting Earth from asteroids that pose a collision hazard. Between NASA, the ESA, and their many institutional partners and private contractors, multiple methods are being developed to divert or destroy oncoming space rocks before they hit us.

However, I’m pretty sure not one of them involves sending a bunch of miners with minimal training into space to plant a nuke inside an asteroid. That would just be silly on its face!

And be sure to check out this video that details the AIDA and Asteroid Impact Mission, courtesy of ESA:

Further Reading: AFP

September 19, 2017 by Matt Williams

Venus Express Probe Reveals the Planet’s Mysterious Night Side

Artist's impression of the Venus Express spacecraft in orbit around Venus. Credit: ESA

Venus’ atmosphere is as mysterious as it is dense and scorching. For generations, scientists have sought to study it using ground-based telescopes, orbital missions, and the occasional atmospheric probe. And in 2006, the ESA’s Venus Express mission became the first probe to conduct long-term observations of the planet’s atmosphere, which revealed much about its dynamics.

Using this data, a team of international scientists – led by researchers from the Japan Aerospace and Exploration Agency (JAXA) – recently conducted a study that characterized the wind and upper cloud patterns on the night side of Venus. In addition to being the first of its kind, this study also revealed that the atmosphere behaves differently on the night side, which was unexpected.

The study, titled “Stationary Waves and Slowly Moving Features in the Night Upper Clouds of Venus“, recently appeared in the scientific journal Nature Astronomy. Led by Javier Peralta, the International Top Young Fellow of JAXA, the team consulted data obtained by Venus Express’ suite of scientific instruments in order to study the planet’s previously-unseen cloud types, morphologies, and dynamics.

Whereas plenty of studies have been conducted of Venus’ atmosphere from soace, this was the first time that a study was not focused on the dayside of the planet. As Dr. Peralta explained in an ESA press statement:

“This is the first time we’ve been able to characterize how the atmosphere circulates on the night side of Venus on a global scale. While the atmospheric circulation on the planet’s dayside has been extensively explored, there was still much to discover about the night side. We found that the cloud patterns there are different to those on the dayside, and influenced by Venus’ topography.“

Since the 1960s, astronomers have been aware that Venus’ atmosphere behaves much differently that those of other terrestrial planets. Whereas Earth and Mars have atmospheres that co-rotate at approximately the same speed as the planet, Venus’ atmosphere can reach speeds of more than 360 km/h (224 mph). So while the planet takes 243 days to rotate once on its axis, the atmosphere takes only 4 days.

This phenomena, known as “super-rotation”, essentially means that the atmosphere moves over 60 times faster than the planet itself. In addition, measurements in the past have shown that the fastest clouds are located at the upper cloud level, 65 to 72 km (40 to 45 mi) above the surface. Despite decades of study, atmospheric models have been unable to reproduce super-rotation, which indicated that some of the mechanics were unknown.

*Artist’s impression of the atmosphere of Venus, showing its lightning storms and a volcano in the distance. Credit and ©: European Space Agency/J. Whatmore*

As such, Peralta and his international team – which included researchers from the Universidad del País Vasco in Spain, the University of Tokyo, the Kyoto Sangyo University, the Center for Astronomy and Astrophysics (ZAA) at Berlin Technical University, and the Institute of Astrophysics and Space Planetology in Rome – chose to look at the unexplored side to see what they could find. As he described it:

“We focused on the night side because it had been poorly explored; we can see the upper clouds on the planet’s night side via their thermal emission, but it’s been difficult to observe them properly because the contrast in our infrared images was too low to pick up enough detail.”

This consisted of observing Venus’ night side clouds with the probe’s Visible and Infrared Thermal Imaging Spectrometer (VIRTIS). The instrument gathered hundreds of images simultaneously and different wavelengths, which the team then combined to improve the visibility of the clouds. This allowed the team to see them properly for the first time, and also revealed some unexpected things about Venus’ night side atmosphere.

What they saw was that atmospheric rotation appeared to be more chaotic on the night side than what has been observed in the past on the dayside. The upper clouds also formed different shapes and morphologies – i.e. large, wavy, patchy, irregular and filament-like patterns – and were dominated by stationary waves, where two waves moving in opposite directions cancel each other out and create a static weather pattern.

*Examples of new types of cloud morphology discovered on the night side of Venus thanks to Venus Express (ESA) and the infrared telescope IRTF (NASA). Credits: ESA/NASA/J. Peralta and R. Hueso.*

The 3D properties of these stationary waves were also obtained by combining VIRTIS data with radio-science data from the Venus Radio Science experiment (VeRa). Naturally, the team was surprised to find these kinds of atmospheric behaviors since they were inconsistent with what has been routinely observed on the dayside. Moreover, they contradict the best models for explaining the dynamics of Venus’ atmosphere.

Known as Global Circulation Models (GCMs), these models predict that on Venus, super-rotation would occur in much the same way on both the dayside and the night side. What’s more, they noticed that stationary waves on the night side appeared to coincide with high-elevation features. As Agustin Sánchez-Lavega, a researcher from the University del País Vasco and a co-author on the paper, explained:

“Stationary waves are probably what we’d call gravity waves–in other words, rising waves generated lower in Venus’ atmosphere that appear not to move with the planet’s rotation. These waves are concentrated over steep, mountainous areas of Venus; this suggests that the planet’s topography is affecting what happens way up above in the clouds.“

This is not the first time that scientists have spotted a possible link between Venus’ topography and its atmospheric motion. Last year, a team of European astronomers produced a study that showed how weather patterns and rising waves on the dayside appeared to be directly connected to topographical features. These findings were based on UV images taken by the Venus Monitoring Camera (VMC) on board the Venus Express.

*Schematic illustration of the proposed behaviour of gravity waves in the vicinity of mountainous terrain on Venus. Credit: ESA*

Finding something similar happening on the night side was something of a surprise, until they realized they weren’t the only ones to spot them. As Peralta indicated:

“It was an exciting moment when we realized that some of the cloud features in the VIRTIS images didn’t move along with the atmosphere. We had a long debate about whether the results were real–until we realised that another team, led by co-author Dr. Kouyama, had also independently discovered stationary clouds on the night side using NASA’s Infrared Telescope Facility (IRTF) in Hawaii! Our findings were confirmed when JAXA’s Akatsuki spacecraft was inserted into orbit around Venus and immediately spotted the biggest stationary wave ever observed in the Solar System on Venus’ dayside.“

These findings also challenge existing models of stationary waves, which are expected to form from the interaction of surface wind and high-elevation surface features. However, previous measurements conducted by the Soviet-era Venera landers have indicated that surface winds might too weak for this to happen on Venus. In addition, the southern hemisphere, which the team observed for their study, is quite low in elevation.

And as Ricardo Hueso of the University of the Basque Country (and a co-author on the paper) indicated, they did not detect corresponding stationary waves in the lower cloud levels. “We expected to find these waves in the lower levels because we see them in the upper levels, and we thought that they rose up through the cloud from the surface,” he said. “It’s an unexpected result for sure, and we’ll all need to revisit our models of Venus to explore its meaning.”

*Artist’s impression of Venus Express performing aerobreaking maneuvers in the planet’s atmosphere in June and July 2014. Credit: ESA–C. Carreau*

From this information, it seems that topography and elevation are linked when it comes to Venus’ atmospheric behavior, but not consistently. So the standing waves observed on Venus’ night side may be the result of some other undetected mechanism at work. Alas, it seems that Venus’ atmosphere – in particular, the key aspect of super-rotation – still has some mysteries for us.

The study also demonstrated the effectiveness of combining data from multiple sources to get a more detailed picture of a planet’s dynamics. With further improvements in instrumentation and data-sharing (and perhaps another mission or two to the surface) we can expect to get a clearer picture of what is powering Venus’ atmospheric dynamics before long.

With a little luck, there may yet come a day when we can model the atmosphere of Venus and predict its weather patterns as accurately as we do those of Earth.

Further Reading: ESA, Nature Astronomy

September 3, 2017September 3, 2017 by Ken Kremer

NASA’s Peggy Whitson Safely Returns Home in Soyuz from Record Breaking Stay in Space

The Soyuz MS-04 vehicle is pictured the moment it touches down with the Expedition 52 crew inside comprising NASA astronauts Peggy Whitson and Jack Fisher and Commander Fyodor Yurchikhin of Roscosmos on Sept. 3, 2017, Kazakhstan time. Credit: NASA/Bill Ingalls

NASA’s Peggy Whitson, America’s most experienced astronaut, returned to Earth safely and smiling Sunday morning on the steppes of Kazakhstan, concluding her record-breaking stay in space aboard the International Space Station (ISS) along with Soyuz crewmates Jack Fischer of NASA and Commander Fyodor Yurchikhin of Roscosmos.

The multinational trio touched down softly on Earth inside their Soyuz MS-04 descent capsule on Saturday evening, Sept. 2 at 9:21 p.m. EDT (shortly after sunrise 7:21 a.m. Kazakhstan time, Sept. 3), some 90 miles southeast of the remote town of Dzhezkazgan in Kazakhstan.

Whitson wrapped up a 288-day extended mission in obviously good health that began in November 2016, spanning 122.2 million miles and 4,623 orbits of Earth – completing her third long-duration stay on the orbiting science outpost spanning Expeditions 50, 51 and 52.

“A flawless descent and landing,” said NASA commentator Rob Navias during the live NASA TV coverage of the return of the ISS Expedition 52 crew Saturday afternoon and evening US time.

“The crew is back on Earth safe and sound.”

NASA astronaut Peggy Whitson, Russian cosmonaut Fyodor Yurchikhin of Roscosmos, and NASA astronaut Jack Fischer undergo routine initial medical checks after returning from their mission aboard the International Space Station at 9:21 p.m. EDT Saturday, Sept. 2, 2017 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), landing southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV

She has now accrued a total of 665 days in space – more than any American astronaut – over the course of her illustrious career during which she set multiple U.S. space records spanning a total of three spaceflights.

Whitson’s 665 total accumulated days in space places her eighth on the all-time space endurance list – just 8 days behind her Russian crewmate and Soyuz Commander Fyodor Yurchikhin who now ranks 7th on the all-time list with 673 days in space on his five flights. She has exceeded the endurance record of her next closest NASA competitor by 131 days – namely NASA astronaut Jeff Williams.

The remarkable 57-year-old Ph.D biochemist by training has spent nearly 2 years of her entire life in space and she holds several other prestigious records as well – including more accumulated time in space than any other woman and the longest single spaceflight by a women – 288 days!

During this mission Whitson became the first woman to serve twice as space station commander. Indeed in 2008 Whitson became the first woman ever to command the space station during her prior stay on Expedition 16 a decade ago. Her second stint as station commander this mission began earlier this year on April 9.

Whitson also holds the record for the most spacewalks and the most time spent spacewalking by a female astronaut. Altogether she has accumulated 60 hours and 21 minutes of EVA time over ten spacewalks -ranking her third most experienced in the world.

Notably Soyuz Commander Yurchikhin ranks fourth in spacewalking experience. Only Russia’s Anatoly Solovyev and NASA’s Michael Lopez-Alegria have more spacewalking time to their credit.

NASA’s Jack Fischer completed his rookie spaceflight accumulating 136 days in space aboard the ISS.

Astronaut Peggy Whitson is pictured May 12, 2017, during the 200th spacewalk at the International Space Station. Credit: NASA

Whitson originally launched to the ISS on Nov 17, 2016 aboard the Russian Soyuz MS-03 spacecraft from the Baikonur Cosmodrome in Kazakhstan, as part of the three person Expedition 50 crew including flight engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency).

Her flight was unexpectedly extended in flight after the Russian government decided to cut back on the number of space station crew cosmonauts this year from three to two to save money. Thus a return seat became available on this Soyuz MS-04 return flight after NASA negotiated an extension with Rosmoscos in April enabling Whitson to remain on board the orbiting outpost an additional three months beyond her than planned June return home.

Whitson’s mission extension proved to be a boon for NASA and science research enabling the US/partner USOS crew complement to be enlarged from three to four full time astronauts much earlier than expected. This allowed NASA to about double the weekly time devoted to research aboard station – a feat not expected to happen until America’s commercial crew vehicles, namely Boeing Starliner and SpaceX Crew Dragon – finally begin inaugural launches next year from the Kennedy Space Center in mid-2018.

NASA Astronaut Peggy Whitson after safe return to Earth on Sept. 2, 2017 ET. Credit: NASA

Descending dramatically while hanging below a single gigantic orange-and-white parachute the scorched Russian Soyuz vehicle fired its braking rockets just moments before touchdown in Kazakhstan to cushion the crew for a gentle landing under beautifully sunny skies.

A live NASA TV video feed captured the thrilling descent for over 14 minutes after the main parachute deployed all the way to the ground under clear blue sunny Sunday morning weather conditions and comfortably local Kazakh temperatures of 77 degrees F.

“Everything today went in perfect fashion from the undocking, to the deorbit burn to landing,” said Navias. “It went by the book with no issues.”

“We saw a spectacular 14 minute long live video of the Soyuz descent and landing.”

The Soyuz MS-04 carrying NASA astronauts Peggy Whitson and Jack Fischer and Fyodor Yurchikin of Roscosmos back to Earth from the International Space Station touched down at at 9:21 p.m. EDT Saturday, Sept. 2 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV

Russian search and recovery forces quickly arrived via a cluster of MI-8 helicopters after the soft landing to begin their normal procedures to extract the three Expedition 52 crew members from their cramped Soyuz descent module.

Soyuz Commander Yurchikhin in the center seat was hauled out first, followed by Fischer in the left side seat and lastly Whitson in the right seat. All 3 were placed on reclining seats sitting side by side and appeared quite well, conversing and speaking via satellite phones.

A group of Russian and US medical teams were on hand to check the astronauts and cosmonauts health and help the crewmates begin readapting to the tug of Earth’s gravity they have not experienced after many months of weightlessness in space.

Whitson’s final planned news conference from space with the media to sum up her experiences this past Wednesday had to be cancelled due to the catastrophic flooding events from Hurricane Harvey impacting Houston and elsewhere in Texas – including Mission Control which was forced to close multiple days.

The crews had bid their final farewells earlier and closed the hatches between the Soyuz and station at 2:40 p.m. EDT Saturday.

After conducting final spacecraft systems checks the trio unhooked the latches and undocked from the International Space Station at 5:58 p.m. EDT to begin their voyage home through the scorching heats of reentry in the Earth’s atmosphere that reached over 2500 degrees F (1400 degrees C) on the outside.

“While living and working aboard the world’s only orbiting laboratory, Whitson and Fischer contributed to hundreds of experiments in biology, biotechnology, physical science and Earth science, welcomed several cargo spacecraft delivering tons of supplies and research experiments, and conducted a combined six spacewalks to perform maintenance and upgrades to the station,” said NASA.

“Among their scientific exploits, Whitson and Fischer supported research into the physical changes to astronaut’s eyes caused by prolonged exposure to a microgravity environment. They also conducted a new lung tissue study that explored how stem cells work in the unique microgravity environment of the space station, which may pave the way for future stem cell research in space.”

“Additional research included an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment, and the study of plant physiology and growth in space using an advanced plant habitat. NASA also attached the Cosmic Ray Energetics and Mass Investigation (ISS CREAM) on the outside of the space station in August, which is now observing cosmic rays coming from across the galaxy.”

Astronaut Peggy Whitson signs her autograph near an Expedition 50 mission patch attached to the inside the International Space Station. Credit: NASA

ISS Expedition 53 began at the moment of undocking from the space station, now under the command of veteran NASA astronaut Randy Bresnik since the official change of command ceremony on Friday.

Along with his crewmates Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency), the three-person crew will operate the station for the next 10 days until the imminent arrival of three new crew members.

The station will get back to a full complement of six crewmembers after the upcoming Sept. 12 launch and fast track 4 orbit 6 hour docking of NASA astronauts Mark Vande Hei and Joe Acaba of NASA and Alexander Misurkin of Roscosmos aboard the next Soyuz MS-06 spacecraft departing from the Baikonur Cosmodrome, Kazakhstan.

Meanwhile the next launch from the Kennedy Space Center is slated for this Thursday, Sept.7 is the SpaceX Falcon 9 carrying the USAF X-37B OTV-5 military mini-shuttle to low Earth orbit -detailed here.

Peggy Whitson set the record on Sept. 2, 2017, for most cumulative days living and working in space by a NASA astronaut at 665 days. Credit: NASA

Expedition 52 Flight Engineer Peggy Whitson of NASA, Commander Fyodor Yurchikhin of the Russian space agency Roscosmos and Flight Engineer Jack Fischer of NASA float through the Harmony module of the International Space Station. Credits: NASA

Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Ken Kremer

Soyuz has split into 3 modules 139.8 km above Earth. Crew parachutes to landing inside Descent Module at 9:22 pm ET Sept. 2, 2017. Credit: NASA

Expedition 52 crew returns to Earth Sept. 2, 2017. Credit: NASA

Peggy Whitson @AstroPeggy is 3rd place all-time for cumulative spacewalk time with 10 spacewalks totaling 60 hours, 21 minutes. Credit: NASA

August 9, 2017August 11, 2017 by Ken Kremer

Sunshield Layers Installed on NASA’s James Webb Space Telescope as Mirror Cryo Cooling Testing Commences

The complex multilayered sunshield that will protect the delicate optics and state of the art infrared science instruments of NASA’s James Webb Space Telescope (JWST) is now fully installed on the spacecraft bus in California, completing another major milestone on the path to launch, NASA announced.

Meanwhile a critical cryogenic cooling test of Webb’s mirrors and science instrument bus has commenced inside a giant chamber at NASA’s Johnson Space Center in Texas, marking another major milestone as the mammoth telescope comes together after years of development.

NASA’s $8.8 Billion James Webb Space Telescope is the most powerful space telescope ever built and is the scientific successor to the phenomenally successful Hubble Space Telescope (HST).

The Webb telescopes groundbreaking tennis court sized sunshield subsystem consists of five layers of kapton that will keep the optics and instruments incredibly cool, by reducing the incoming sunside facing temperature more than 570 degrees Fahrenheit. Each layer is as thin as a human hair.

“The sunshield layers work together to reduce the temperatures between the hot and cold sides of the observatory by approximately 570 degrees Fahrenheit,” according to NASA. “Each successive layer of the sunshield is cooler than the one below.”

The painstaking work to integrate the five sunshield membranes was carried out in June and July by engineers and technicians working at the Northrop Grumman Corporation facility in Redondo Beach, California.

“All five sunshield membranes have been installed and will be folded over the next few weeks,” said Paul Geithner, deputy project manager – technical for the Webb telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

Deployment tests of the folded sunshield start in August.

Webb’s four research instruments cannot function without the essential cooling provided by the sunshield deployment.

Northrop Grumman designed the Webb telescope’s optics and spacecraft bus for NASA’s Goddard Space Flight Center in Greenbelt, Maryland, which manages Webb.

Two sides of the James Webb Space Telescope (JWST). Credit: NASA

“This is a huge milestone for the Webb telescope as we prepare for launch,” said Jim Flynn, Webb sunshield manager, Northrop Grumman Aerospace Systems.

“The groundbreaking tennis court sized sunshield will shield the optics from heat and assist in providing the imaging of the formation of stars and galaxies more than 13.5 billion years ago.”

Webb is designed to look at the first light of the Universe and will be able to peer back in time to when the first stars and first galaxies were forming. It will also study the history of our universe and the formation of our solar system as well as other solar systems and exoplanets, some of which may be capable of supporting life on planets similar to Earth.

After successfully passing a rigorous series of vibration and acoustic environmental tests earlier this year at NASA Goddard in March, the mirror and instrument assembly was shipped to NASA Johnson in May for the cryo cooling tests.

“Those tests ensured Webb can withstand the vibration and noise created during the telescope’s launch into space. Currently, engineers are analyzing this data to prepare for a final round of vibration and acoustic testing, once Webb is joined with the spacecraft bus and sunshield next year,” says NASA.

The cryogenic cooling test will last 100 days and is being carried out inside the giant thermal vacuum known as Chamber A at the Johnson Space Center in Houston.

“A combination of liquid nitrogen and cold gaseous helium will be used to cool the telescope and science instruments to their operational temperature during high-vacuum operations,” said Mark Voyton, manager of testing effort, who works at the NASA Goddard Space Flight Center in Greenbelt, Maryland.

Next year, the tennis-court sized sunshield and spacecraft bus will be combined to make up the entire observatory.

The first layer of the Webb telescope sunshield installed at Northrop Grumman’s clean room in Redondo Beach, California. Credits: Northrop Grumman Corp.

The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

Assembly of the Webb telescope is currently on target and slated to launch on an ESA Ariane V booster from the Guiana Space Center in Kourou, French Guiana in October 2018.

NASA and ESA are currently evaluating a potential launch scheduling conflict with ESA’s BepiColombo mission to Mercury.

Technicians work on the James Webb Space Telescope in the massive clean room at NASA’s Goddard Space Flight Center, Greenbelt, Maryland, on Nov. 2, 2016, as the completed golden primary mirror and observatory structure stands gloriously vertical on a work stand, reflecting incoming light from the area and observation deck. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

………….

Learn more about the upcoming SpaceX Dragon CRS-12 resupply launch to ISS on Aug. 14, ULA Atlas TDRS-M NASA comsat on Aug. 18, 2017 Solar Eclipse, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Aug 11-14: “SpaceX CRS-12 and CRS-11 resupply launches to the ISS, Inmarsat 5, BulgariaSat 1 and NRO Spysat, EchoStar 23, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, ULA Atlas/John Glenn Cygnus launch to ISS, SBIRS GEO 3 launch, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

July 30, 2017August 1, 2017 by Ken Kremer

Veteran Multinational Trio Launches on Soyuz and Arrives at International Space Station

The Soyuz MS-05 rocket is launched with Expedition 52 flight engineer Sergei Ryazanskiy of Roscosmos, flight engineer Randy Bresnik of NASA, and flight engineer Paolo Nespoli of ESA (European Space Agency), Friday, July 28, 2017 at the Baikonur Cosmodrome in Kazakhstan. Photo Credit: (NASA/Joel Kowsky)

An all veteran multinational trio of astronauts and cosmonauts rocketed to orbit aboard a Russian Soyuz capsule and safely arrived at the International Space Station (ISS) after a fast track rendezvous on Friday, July 28.

NASA astronaut Randy Bresnik, Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency) docked at the orbiting outpost at 5:54 p.m. EDT (2154 GMT) Friday just six hours after departing our Home Planet.

The three crewmates launched aboard the Russian Soyuz MS-05 spacecraft from the Baikonur Cosmodrome in Kazakhstan during a typically hot mid-summers night at 9:41 p.m. Baikonur time, or 11:41 a.m. EDT, 1541 GMT, as the booster and Baikonur moved into the plane of the space station’s orbit. They blasted to space from the same pad as Yuri Gagarin, the first man in space.

The entire launch sequence aboard the Soyuz rocket performed flawlessly and delivered the Soyuz capsule to its targeted preliminary orbit flowing by the planned opening of the vehicles solar arrays and antennas.

The Russian Soyuz MS-05 carrying NASA astronaut Randy Bresnik, Sergey Ryazanskiy of the Russian space agency Roscosmos, and Paolo Nespoli of ESA (European Space Agency) docked to the International Space Station at 5:54 p.m. on Friday, July 28, 2017. Credits: NASA Television

Following a rapid series of orbit raising maneuvers, the Soyuz reached the ISS after 4 orbits and six hours to successfully complete all the rendezvous and docking procedures.

The Soyuz docked at the Earth-facing Russian Rassvet module as the spaceships were flying some 250 mi (400 km) over Germany.

Following the standard pressurization and leak checks, the hatches between the spacecraft and station were opened from inside the ISS at about 9:45 p.m. EDT.

The new trio of Bresnik, Ryazanskiy and Nespoli then floated one by one from the Soyuz into the station and restored the outpost to a full strength crew of six humans.

The veteran space flyers join Commander Fyodor Yurchikhin of Roscosmos and Flight Engineers Peggy Whitson and Jack Fischer of NASA who are already serving aboard.

Thus begins Expedition 52 aboard the million pound orbiting science complex.

This is the second space flight for both Bresnik and Ryazanskiy and the third for Nespoli.

Bresnik previously flew to the space station as a member of the STS-129 space shuttle Atlantis mission in November 2009. The 10 day mission delivered two Express Logistics Carriers (ELC racks) to the space station as part of approximately 30,000 pounds of replacement parts.

Bresnik performed two spacewalks for a total of 11 hours and 50 minutes during the STS-129 mission. He is slated to take command of the ISS as a member of Expedition 53.

The six person crew of Space Shuttle Atlantis walk out from crew quarters at 10:38 AM to greet the cheering crowd of media and NASA officials and then head out to pad 39 A to strap in for space launch with hours. Randy Bresnik is third from left. Credit: Ken Kremer/kenkremer.com

The new Expedition 52 crew will spend a four and a half month stint aboard the station and continue over 250 ongoing science investigations in fields such as biology, Earth science, human research, physical sciences and technology development.

Bresnik, Ryazanskiy and Nespoli are slated to stay aboard until returning to Earth in December.

Whitson, Fischer and Yurchikhin are in the home stretch of their mission and will retun to Earth in September. Shortly after their departure, NASA astronauts Mark Vande Hei and Joseph Acaba and Russian cosmonaut Alexander Misurkin will launch on the next Soyuz from Kazakhstan to join the Expedition 53 crew.

Whitson is the most experienced US astronaut with time in space. Her record setting cumulative time in space will exceed 600 days and include a 9 month stay on this flight upon her return to Earth.

She most recently launched to the ISS last year on Nov 17, 2016 aboard a Russian Soyuz capsule from the Baikonur Cosmodrome. This is her 3rd long duration stay aboard the station.

Whitson also holds the record for most spacewalks by a female astronaut. Altogether she has accumulated 53 hours and 23 minutes of EVA time over eight spacewalks.

The newly-expanded Expedition 52 crew expect to welcome a pair of unmanned US cargo ships carrying new research experiments and supplies, namely the SpaceX Dragon as soon as August and Orbital ATK Cygnus a month or two later, on NASA-contracted commercial resupply missions.

The SpaceX CRS-12 mission will carry investigations ”the crew will work on including a study developed by the Michael J. Fox Foundation of the pathology of Parkinson’s disease to aid in the development of therapies for patients on Earth. The crew will use the special nature of microgravity in a new lung tissue study to advance understanding of how stem cells work and pave the way for further use of the microgravity environment in stem cell research. Expedition astronauts also will assemble and deploy a microsatellite investigation seeking to validate the concept of using microsatellites in low-Earth orbit to support critical operations, such as providing lower-cost Earth imagery in time-sensitive situations such as tracking severe weather and detecting natural disasters.”

Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

July 7, 2017 by Matt Williams

Gaia Finds Six Stars Zipping out of the Milky Way

An artist's conception of a hypervelocity star that has escaped the Milky Way. Credit: NASA

In 2013, the European Space Agency launched the Gaia spacecraft. As the successor to the Hipparcos mission, this space observatory has spent the past three and a half years gathering data on the cosmos. Before it retires sometime next year (though the mission could be extended), this information will be used to construct the largest and most precise 3D astronomical map ever created.

In the course of surveying the cosmos, Gaia has also revealed some very interesting things along the way. For example, after examining the Gaia catalog with a specially-designed artificial neural network, a team of European researchers recently detected six new hypervelocity stars in the Milky Way. And one of these stars is moving so fast that it may eventually leave our galaxy.

Their study – titled “An Artificial Neural Network to Discover Hypervelocity Stars: Candidates in Gaia DR1/TGAS” – was recently published in the Monthly Notices of the Royal Astronomical Society. It was presented late last month at the European Week of Astronomy and Space Science, which was being held from June 26th to June 30th in Prague, Czech Republic.

*Artist’s conception of the Gaia telescope backdropped by a photograph of the Milky Way taken at the European Southern Observatory. Credit: ESA/ATG medialab; background: ESO/S. Brunier*

Hypervelocity stars are a rare and fascinating thing. Whereas all stars in the Milky Way are in constant motion, orbiting around the center of our galaxy, some are accelerated to speeds of up to hundreds of kilometers per second. In the past, astronomers have deduced that these fast-moving stars are the result of a close stellar encounter or a supernova explosion of a stellar companion.

And a little over a decade ago, astronomers became aware of a new class of high-speed stars that are believed to have been accelerated from past interactions with the supermassive black hole (Sagittarius A*) that sits at the center of our galaxy. These stars are extremely important to the study of the overall structure of the Milky Way, as they are indicative of the kinds of events and forces that have shaped its history.

As Elena Maria Rossi, from Leiden University in the Netherlands and one of the co-authors on the paper, explained in an ESA press release:

“These are stars that have traveled great distances through the Galaxy but can be traced back to its core – an area so dense and obscured by interstellar gas and dust that it is normally very difficult to observe – so they yield crucial information about the gravitational field of the Milky Way from the centre to its outskirts.“

*Artist’s impression of stars speeding through the Galaxy. Credit: ESA*

Finding such stars is no easy task, mainly because their velocity makes them extremely difficult to spot in the vast and crowded disk of the Milky Way. As a result, scientists have relied on looking for young, massive stars (2.5 to 4 Solar masses) in the old stellar population of the Galactic. Basically, their young age and high masses are indications that they might not have originated there.

Combined with measurements of their past speeds and paths, this method has confirmed the existence of hypervelocity stars in the past. However, only 20 hypervelocity stars have been spotted to date, and they have all been young and massive in nature. Scientists believe that many more stars of other ages and masses are also being accelerated through the Milky Way, but were previously unable to spot them.

To address this, the European team – led by from Tomasso Marchetti of Leiden University in the Netherlands – began considering how to use Gaia‘s vast dataset to optimize the search for more hypervelocity stars. After testing various methods, they adopted the artificial neural net approach – i.e. using a machine learning algorithm – to search through the star census data Gaia is in the process of gathering.

Beginning in the first half of 2016, the team began developing and training this program to be ready for the first release of Gaia data – which occurred a few months later on Sept. 14th, 2016. As Tommaso Marchetti, a PhD student at Leiden University, described the process:

“In the end, we chose to use an artificial neural network, which is software designed to mimic how our brain works. After proper ‘training’, it can learn how to recognize certain objects or patterns in a huge dataset. In our case, we taught it to spot hypervelocity stars in a stellar catalogue like the one compiled with Gaia.”

*Artist’s impression of a hypervelocity star that was detected using the ESO’s Very Large Telescope. Credit: ESO*

In addition to a map with the positions of over a billion stars, this first data release included a smaller catalogue with the distances and motions for two million stars. This catalog – which is known as the Tycho-Gaia Astrometric Solution (TGAS) – combined data from both the first year of the Gaia mission and with data from the Hipparcos mission, and is essentially a taste of what’s to come from Gaia.

On the day of the catalog’s release, Marchetti and his team ran their algorithm on the two million stars within the TGAS, which revealed some interesting finds. “In just one hour, the artificial brain had already reduced the dataset to some 20 000 potential high-speed stars, reducing its size to about 1%,” said Rossi. “A further selection including only measurements above a certain precision in distance and motion brought this down to 80 candidate stars.”

The team then examined these 80 stars in more detail, and compared the information about their motions to data from other catalogues. Paired with additional observations, they eventually found six stars which appeared to be moving faster than 360 km/s. One even appeared to be exceeding 500 km/s, which means that it is no longer bound by the gravity of our Milky Way and will eventually leave it altogether.

But perhaps the sot significant aspect of this find is the fact these stars are not particularly massive like the previous 20 that had been discovered, and were comparable in mass to our Sun. In addition, the 5 slower stars are likely to become a focal point of study, as scientists are eager to determine what slowed them down. One possible explanation is that interaction with the galaxy’s dark matter might have been responsible.

*Gaia’s first sky map. Credit: ESA/Gaia/DPAC. Credit: A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC.*

Much as the TGAS has been merely an early indication of the vast and valuable data Gaia will eventually provide, this study showcases the kinds of discoveries and research that this data will enable. By with not just 2 million, but a billion stars to study, astronomers are sure to reveal many new and exciting things about the dynamics of our Milky Way and the kinds of forces that have shaped it.

For this purpose, Marchetti and his team are upgrading their program to handle the much larger data set, which is scheduled to be released in April of 2018. This catalog will include distance and motions for over a billion stars, as well as velocities for a specific subset. From this, the team may find that fast-moving stars which are being booted out of the Milky Way are a lot more common than previously thought.

And be sure to enjoy this video that shows the paths of these six newly-discovered fast-moving stars, courtesy of the ESA:

Further Reading: ESA

June 22, 2017 by Matt Williams

Snake Rovers Might be the Best Way to Explore the Surface and Tunnels on Mars

The picture shows an imaginary snake robot on Space Station – on the way to inspect anything for the astronaut. Credit: SINTEF

Human space exploration is going to kick into high gear in the coming decades. Within the inner Solar System alone, missions are being planned that will see robotic explorers and crews sent to Near Earth Objects (NEOs), back to the Moon, and even on to Mars. Beyond that, there are even plans to send robotic missions to Europa, Enceladus, Titan, and other “ocean worlds” to look for signs of life.

In all cases, questions natural arise as to what kinds of missions will be most suited to them. In the case of places like Titan (which have low gravity and dense atmospheres) aerial drones are considered the best bet. But when it comes to rocky place like asteroids, the Moon and Mars, the best candidate may be robot snakes, which could find their way through tight spaces and travel underground.

This concept was proposed three years ago by the Foundation for Scientific and Industrial Research (SINTEF), the largest independent research organization in Scandinavia. As part of a project commissioned by the ESA – known as SERPEX – they began studying how robots designed to mimic the movements of snakes could assist astronauts aboard the International Space Station.

*SINTEF researchers Pål Liljebäck and Aksel Transeth, and Knut Robert Fossum of NTNU’s CIRiS, playing with Wheeko the snake robot. Credit: SINTEF/Thor Nielsen.*

But as Aksel Transeth, a senior research scientist at SINTEF, explained in a recent press statement, the possibilities go far beyond the ISS:

“More ambitious applications include potential activities on comets and the Moon. [A] Snake Robot that can assist ISS astronauts in maintaining their equipment is perhaps a solution which can be possible to realize on a more short term.”

Compared to other robotic explorers, the main selling point of a robot snake is that it offers better mobility. For two decades now, NASA has been exploring the Red Planet with robotic rovers, starting with Pathfinder and Sojourner in 1997, Spirit and Opportunity in 2003, and then Curiosity in 2012. And in a little over two years, they will be sending the Mars 2020 rover.

In all cases, these robots get around on six wheels and conduct experiments using instruments on robotic arms. But as the missions teams behind these rovers have learned, mobility can be a challenge. For instance, after five years on the Martian surface, the Spirit rover became stuck in soft soil, where its mission ended. And as successful as these missions have been at conducting research, there are locations that they simply can’t get to.

The SINTEF researchers decided to tackle these issues through biomimicry – i.e. robots that mimic the functions of living creatures. By combining a rover that can navigate over large distances with a snake robot that can crawl along the ground and get into inaccessible places, they believe that future missions would be able to go places and collect samples in ways that other missions could not.

*The ESA recently elaborated its plan to create a Moon base by the 2030s. Credit: ESA/Foster+Partners*

As Transeth explained back in 2013, this pairing would open up all kinds of possibilities. “We are looking at several alternatives to enable a rover and a robot to work together,” he said. “Since the rover has a powerful energy source, it can provide the snake robot with power through a cable extending between the rover and the robot. If the robot had to use its own batteries, it would run out of power and we would lose it.”

In the configuration Transeth and his colleagues are envisioning, the rover would handle the task of traveling over long distances and then be able to dispatch the snake to crawl into tight inaccessible areas. They would be connected by a cable that would provide electricity, communication signals and would be used to pull the snake back in. In this sense, the snake would act like one of the rover’s arms, but would have the ability to travel autonomously.

“We believe that we can design a robot that can hold on, roll itself up and then extend its body in order to reach new contact points,” said Transeth. “Moreover, we believe that it can creep in among equipment components on the ISS and use equipment surfaces to gain traction in order to keep moving forward – much in the same way as real snakes do in the wild.”

On Mars, sample collection is crucial to many space agency’s research. For the Curiosity rover, the presence of hydrated minerals and clays in soil samples confirmed that Mars once had a warmer, wetter climate. And in the future, scientists hope to find biomakers in Martian soil that could indicate the presence (past or present) of biological life. In this respect, a snake robot would prove very useful since it could access underground recesses the rover cannot.

*The sinuous rille known as Rima Ariadaeus, as photographed from Apollo 10, which is the result of a collapsed lava tube. Credit: NASA*

On the Moon, snake robots could be especially useful in helping the ESA establish it’s proposed “Moon Village” – a permanent base for scientific activity, tourism and mining that would also act as a successor to the ISS. The most likely location for this base could be within stable lava tubes or subterranean tunnels, which would provide natural shielding from meteors, solar radiation and cosmic rays.

But before such construction of this base can take place, these tunnels and lava tubes will have to be inspected to ensure that they are safe for human habitation. The ESA has also been committed to studying comets in recent years, which included sending the Rosetta space probe and Philae lander to rendezvous with the comet 67P/Tsjurjumov–Gerasimenko in 2014.

Unfortunately, the lander experienced problems when its system of harpoons (designed to hold it in place) failed to deploy. As a result, it was forced to make another soft landing which left it in a position and location that was not optimal for research. In the future, the ESA could get avoid this by sending a probe to the surface that would deploy the snakes to the surface, which could then burrow into the comet’s interior.

But in the meantime, operations aboard the ISS remain the most realistic and likely application for these robots. Here, astronauts are engaged in ongoing scientific experiments, but are also responsible for maintaining the station and all of its equipment. In this latter respect, the SERPEX project could certainly prove useful, providing them with robot helpers that could help with the regular maintenance.

“It’s possible that a robot could carry out some of the routine inspection and maintenance work,” said Transeth. “The experiments are stacked in the shelf sections, behind which corrosion can occur. To find this out, inspections have to be made. A snake robot could creep behind the sections, carry out an inspection, and perhaps even perform small maintenance tasks.”

Some of the concepts developed by SINTEF so far include the Aiko robot, which was developed to produce a portable system for experimenting with snake robot locomotion. The robot consists of several identical joint modules with two motorized degrees of freedom each. As you can see from the video above, it is propelled by contact forces between the robot and the obstacles in its way.

And then there’s the Wheeko robot, which was developed by SINTEF in conjunction with the Center for Interdisciplinary Research in Space (CIRiS), and the Norwegian Space Center (NSC). Much like Aiko, this experimental robot was designed to study snake robot locomotion across flat surfaces. It consists of ten identical joint modules with two motorized degrees of freedom each.

But of course, developing snake robots that can handle various tasks while working in different environments – ranging from working in micro-gravity aboard the ISS to snaking their way through tunnels on a body with gravity – presents many challenges. And in the coming years, Transeth and his colleagues will be looking for ways to address all of them.

“We want to find out what specifications a snake robot system requires,” he said. “For example, what kind of sensors does the robot need to obtain an adequate understand its surroundings? What technologies are available to help us meet these needs, and what new technologies will have to be developed? What uncertainties are involved in terms to what it may be possible to achieve?”

Already, astronauts aboard the ISS have robotic helpers in the form of the Synchronized Position Hold Engage and Reorient Experimental Satellite (SPHERES). These free flying satellites serve as test beds for a diverse range of hardware and software, all of which is critical for future space missions that use distributed spacecraft architecture.

Soon enough, they will be replaced by a drone called Astrobee – a robotic cube packed with sensors, cameras, computers, and a propulsion system. The brainchild of the Ames Research Center’s Intelligent Robotics Group, this drone will be flying around the ISS and making inspections.

Some of the technology used by Astrobee will be similar to what Transeth and his colleague are hoping to apply to their snake robot system. As such, they hope to learn much from this drone’s time aboard the ISS and incorporate the lessons that are learned from it.

Further Reading: SINTEF