esa Archives

January 30, 2018January 30, 2018 by Matt Williams

The Brightest Star in the Sky, Sirius, was Hiding a Cluster of Stars. Found by Gaia

Obscured Sirius reveals Gaia 1 cluster. Credit and Copyright: H. Kaiser/ESA

In December of 2013, the European Space Agency’s Gaia mission took to space. Since that time, this space observatory has been studying a billion astronomical objects – including stars, planets, comets, asteroids and galaxies – for the sake of creating the most precise 3D space catalog ever made. By the time the mission wraps up (later this year, barring extensions), it is expected to reveal some truly amazing things about our Universe.

In fact, with the first release of its data, the Gaia probe revealed something that has gone completely unnoticed until now. While viewing Sirius, the brightest star in the night sky, Gaia revealed a stellar cluster that had previously been obscured by Sirius’ bright light. This cluster – now known as the Gaia 1 Cluster – is now available to the public thanks to a picture that was taken by an amateur astronomer from Germany.

Given its brightness and the fact that it is visible from just about anywhere on the planet, Sirius has been known since antiquity, and was featured prominently in the astrological and astronomical traditions of many cultures. To the ancient Egyptians, the star was used to keep track of time and agriculture, since its return to the sky was linked to the annual flooding of the Nile.

*Artist’s impression of a white dwarf star in orbit around Sirius (a main sequence white dwarf). Credit: NASA, ESA and G. Bacon (STScI)*

In Ancient Greek mythology, Sirius represented the eye of the Canis Major constellation. Along with Canis Minor, it formed the Great Dog that diligently followed Orion, the Hunter. In Chinese astronomy, the star is known as the star of the “celestial wolf” and lies in the Mansion of Jing. And when Ptolemy created his influential astronomical tract in the 3rd century CE (the Almagest), he used Sirius as the location for the globe’s central meridian.

By the mid-19th century, astronomers determined that Sirius is actually a binary star system. Essentially, the star system consists of a main sequence white dwarf that is roughly two Solar masses and a white dwarf that is slightly more massive than our Sun. Sirius’ bright appearance means that astronomers have had plenty of light to study the star’s properties, but also causes it to outshine other celestial objects in its vicinity.

However, in the course of counting the stars around Sirius, Gaia’s sophisticated instruments managed to detect the Gaia 1 Cluster for the first time. News of both this cluster and another newly-discovered one (the Gaia 2 Cluster) became public after the first release of Gaia data, which took place in September 2016. News of this discovery sent ripples through the astronomical community and has led to much research into this cluster and its companion.

News of the discovery also prompted attempts to visually capture the cluster. Roughly a year ago, Harald Kaiser – an amateur astronomer from Karlsruhe, Germany – attended a public talk about the Gaia mission, where he learned about the Gaia 1 Cluster being spotted near Sirius. Kaiser then eagerly waited for the next clear night so he could find the cluster himself using his 30 cm telescope.

After snapping a picture of Sirius and correcting for its bright glare, he was able to capture some of the brightest stars in the cluster. As you can see from the image he took (at top), the cluster lies slightly to the left of Sirius and shows a smattering of some of its largest and brightest stars. In addition to revealing the location of this cluster, Kaiser’s efforts are also part of a larger effort to capitalize on the Gaia mission’s progress.

According to a study released in February of last year – led by Sergey Kopsov of Carnegie Melon University – Gaia 1 is a particularly massive cluster. In essence, it weighs in at an impressive 22,000 Solar Masses, is about 29 light-years (9 parsecs) in diameter, and is located 15,000 light years (4.6 kiloparsecs) from Earth. In addition to its size and the fact that it was previously undiscovered, it’s proximity also makes it an opportune target for future research.

The announcement of this cluster has also caused a fair degree of excitement in the scientific community since it validates the capabilities of Gaia and serves as an example of the kinds of things it is expected to reveal. Astronomers are now looking forward to Gaia’s second data release (planned for April 25th) which is expected to provide even more possibilities for new and exciting discoveries.

And be sure to check out this video about the Gaia mission, courtesy of the ESA:

Further Reading: ESA

January 24, 2018 by Matt Williams

This was the Snowstorm Rosetta Saw When it Got 79 km Away From Comet 67P

Rosetta mission poster showing the deployment of the Philae lander to comet 67P/Churyumov-Gerasimenko.. Credit: ESA/ATG medialab (Rosetta/Philae); ESA/Rosetta/NavCam (comet)

In August of 2014, the ESA’s Rosetta mission made history when it rendezvoused with the Comet 67P/Churyumov–Gerasimenko. For the next two years, the probe flew alongside the comet and conducted detailed studies of it. And in November of 2014, Rosetta deployed its Philae probe onto the comet, which was the first time in history that a lander was deployed to the surface of a comet.

During the course of its mission, Rosetta revealed some truly remarkable things about this comet, including data on its composition, its gaseous halo, and how it interacts with solar wind. In addition, the probe also got a good look at the endless stream of dust grains that were poured from the comet’s surface ice as it approached the Sun. From the images Rosetta captured, which the ESA just released, it looked a lot like driving through a snowstorm!

The image below was taken two years ago (on January 21st, 2016), when Rosetta was at a distance of 79 km from the comet. At the time, Rosetta was moving closer following the comet reaching perihelion, which took place during the previous August. When the comet was at perihelion, it was closer to the Sun and at its most active, which necessitated that Rosetta move farther away for its own protection.

*Image of the dust and particles the Rosetta mission was exposed to as it flew alongside Comet 67P/Churyumov–Gerasimenko. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA*

As you can see from the image, the environment around the comet was extremely chaotic, even though it was five months after the comet was at perihelion. The white streaks reveal the dust grains as they flew in front of Rosetta’s camera over the course of a 146 second exposure. For the science team directing Rosetta, flying the spacecraft through these dust storms was like trying to drive a car through a blizzard.

Those who have tried know just how dangerous this can be! On the one hand, visibility is terrible thanks to all the flurries. On the other, the only way to stay oriented is to keep your eyes pealed for any landmarks or signs. And all the while, there is the danger of losing control and colliding with something. In much the same way, passing through the comet’s dust storms was a serious danger to the spacecraft.

In addition to the danger of collisions, flying through these clouds was also hazardous for the spacecraft’s navigation system. Like many robotic spacecraft, Rosetta relies on star trackers to orient itself – where it recognizes patterns in the field of stars to orient itself with respect to the Sun and Earth. When flying closer to the comet, Rosetta’s star trackers would occasionally become confused by dust grains, causing the craft to temporarily enter safe mode.

Artist’s impression of the Rosetta probe signalling Earth. Credits: ESA-C.Carreau

This occurred on March 28th, 2015 and again on May 30th, 2016, when Rosetta was conducting flybys that brought it to a distance of 14 and 5 km from the comet’s surface, respectively. On both occasions, Rosetta’s navigation system suffered from pointing errors when it began tracking bright dust grains instead of stars. As a result, on these occasions, the mission team lost contact with the probe for 24 hours.

As Patrick Martin, the ESA’s Rosetta mission manager, said during the second event:

“We lost contact with the spacecraft on Saturday evening for nearly 24 hours. Preliminary analysis by our flight dynamics team suggests that the star trackers locked on to a false star – that is, they were confused by comet dust close to the comet, as has been experienced before in the mission.”

Despite posing a danger to Rosetta’s solar arrays and its navigation system, this dust is also of high scientific interest. During the spacecraft’s flybys, three of its instruments studied tens of thousands of grains, analyzing their composition, mass, momentum and velocity, and also creating 3D profiles of their structure. By studying these tiny grains, scientists were also able to learn more about the bulk composition of comets.

*Another snapshot of Comet 67P/Churyumov–Gerasimenko’s dusty emissions, taken on Jan. 21st, 2016. Credit: ESA*

Before it reached its grand finale and crashed into the comet’s surface on September 30th, 2016, Rosetta made some unique scientific finds about the comet. These included mapping the comet’s surface features, discerning its overall shape, analyzing the chemical composition of its nucleus and coma, and measuring the ratio of water to heavy water on its surface.

All of these findings helped scientists to learn more about how our Solar System formed and evolved, and shed some light on how water was distributed throughout our Solar System early in its history. For instance, by determining that the ratio of water to heavy water on the comet was much different than that of Earth’s, scientists learned that Earth’s water was not likely to have come from comets like Comet 67P/Churyumov–Gerasimenko.

On top of that, the spacecraft took more than a hundred thousand image of the comet with its high-resolution OSIRIS camera (including the ones shown here) and its navigation camera. These images can be perused by going to the ESA’s image browser archive. I’m sure you’ll agree, they are all as beautiful as they are scientifically relevant!

Further Reading: ESA

January 22, 2018 by Evan Gough

A New Kind of Propulsion System That Doesn’t Need Propellant. It Converts Electricity into Thrust and Vice Versa.

The proposed "space-tie" propulsion system being patented by Spanish scientists could be useful on Satellites like the ESA's Sentinel-1, pictured. Image: ESA/ATG

Some of the best things in science are elegant and simple. A new propulsion system being developed in Spain is both those things, and could help solve a growing problem with Earth’s satellites: the proliferation of space junk.

Researchers at Universidad Carlos III de Madrid (UC3M) and the Universidad Politécnica de Madrid (UPM) in Spain are patenting a new kind of propulsion system for orbiting satellites that doesn’t use any propellant or consumables. The system is basically a tether, in the form of an aluminum tape a couple kilometers long and a couple inches wide, that trails out from the satellite. The researchers call it a space tie.

“This is a disruptive technology because it allows one to transform orbital energy into electrical energy and vice versa without using any type of consumable”. – Gonzalo Sánchez Arriaga, UC3M.

The lightweight space tie is rolled up during launch, and once the satellite is in orbit, it’s deployed. Once deployed, the tape can either convert electricity into thrust, or thrust into electricity. The Spanish researchers behind this say that the space-ties will be used in pairs.

The system is based on what is called a “low-work-function” tether. A special coating on the tether has enhanced electron emission properties on receiving sunlight and heat. These special properties allow it to function in two ways. “This is a disruptive technology because it allows one to transform orbital energy into electrical energy and vice versa without using any type of consumable,” said Gonzalo Sánchez Arriaga, Ramón y Cajal researcher at the Bioengineering and Aerospace Engineering Department at UC3M.

As a satellite loses altitude and gets closer to Earth, the tether converts that thrust-caused-by-gravity into electricity for the spacecraft systems to use. When it comes to orbiting facilities like the International Space Station (ISS), this tether system could solve an annoying problem. Every year the ISS has to burn a significant amount of propellant to maintain its orbit. The tether can generate electricity as it moves closer to Earth, and this electricity could replace the propellant. “With a low- work function tether and the energy provided by the solar panel of the ISS, the atmospheric drag could be compensated without the use of propellant”, said Arriaga.

“Unlike current propulsion technologies, the low-work function tether needs no propellant and it uses natural resources from the space environment such as the geomagnetic field, the ionospheric plasma and the solar radiation.” – Gonzalo Sánchez Arriaga, UC3M.

For satellites with ample on-board power, the tether would operate in reverse. It would use electricity to provide thrust to the space craft. This is especially useful to satellites near the end of their operational life. Rather than languish in orbit for a long time as space junk, the derelict satellite could be forced to re-enter Earth’s atmosphere where it would burn up harmlessly.

The space-tie system is based on what’s called Lorentz drag. Lorentz drag is an electrodynamic effect. (Electrodynamics enthusiasts can read all about it here.) I won’t go too deeply into it because I’m not a physicist, but the Spanish researchers suggest that the Lorentz drag can be easily observed by watching a magnet fall through a copper tube. Here’s a video.

Space organizations have shown interest in the low-work-function tether, and the Spanish team is getting the word out to experts in the USA, Japan, and Europe. The next step is the manufacture of prototypes. “The biggest challenge is its manufacturing because the tether should gather very specific optical and electron emission properties,” says Sánchez Arriaga.

The Spanish Ministry of Economy, Industry and Competitiveness has awarded the Spanish team a grant to investigate materials for the system. The team has also submitted a proposal to the European Commission’s Future and Emerging Technologies (FET-Open) consortium for funding. “The FET-OPEN project would be foundational because it considers the manufacturing and characterization of the first low-work-function tether and the development of a deorbit kit based on this technology to be tested on a future space mission. If funded, it would be a stepping stone to the future of low-work-function tethers in space” Sanchez Arriaga concluded.

In this video, Gonzalo Sanchez Arriaga explains how the system works. If you don’t speak Spanish, just turn on subtitles.

January 5, 2018 by Matt Williams

The Gaia Mission Could Moonlight as a Gravitational Wave Detector

The ESA's Gaia mission is currently on a five-year mission to map the stars of the Milky Way. Gaia has found evidence for a galactic collision that occurred between 300 million and 900 million years ago. Image credit: ESA/ATG medialab; background: ESO/S. Brunier.

In February of 2016, scientists working for the Laser Interferometer Gravitational-Wave Observatory (LIGO) made the first-ever detection of gravitational waves. Since that time, multiple detections have taken place, thanks in large to part to improvements in instruments and greater levels of collaboration between observatories. Looking ahead, its possible that missions not designed for this purpose could also “moonlight” as gravitational wave detectors.

For example, the Gaia spacecraft – which is busy creating the most detailed 3D map of the Milky Way – could also be instrumental when it comes to gravitational wave research. That’s what a team of astronomers from the University of Cambridge recently claimed. According to their study, the Gaia satellite has the necessary sensitivity to study ultra-low frequency gravitational waves that are produced by supermassive black hole mergers.

The study, titled “Astrometric Search Method for Individually Resolvable Gravitational Wave Sources with Gaia“, recently appeared in the Physical Review Letters. Led by Christopher J. Moore, a theoretical physicist from the Center for Mathematical Sciences at the University of Cambridge, the team included members from Cambridge’s Institute of Astronomy, Cavendish Laboratory, and Kavli Institute for Cosmology.

Artist’s illustration of two merging neutron stars, which are a source of gravitational waves. Credit: National Science Foundation/LIGO/Sonoma State University/A. Simonnet

To recap, gravitational waves (GWs) are ripples in space-time that are created by violent events, such as black hole mergers, collisions between neutron stars, and even the Big Bang. Originally predicted by Einstein’s Theory of General Relativity, observatories like LIGO and Advanced Virgo detect these waves by measuring the way space-time flexes and squeezes in response to GWs passing through Earth.

However, passing GWs would also cause the Earth to oscillate in its location with respect to the stars. As a result, an orbiting space telescope (such as Gaia), would be able to pick up on this by noting a temporary shift in the position of distant stars. Launched in 2013, the Gaia observatory has spent the past few years conducting high-precision observations of the positions of stars in our Galaxy (aka. astrometry).

In this respect, Gaia would look for small displacements in the massive field of stars it is monitoring to determine if gravitational waves have passed through the Earth’s neighborhood. To investigate whether or not Gaia was up to the task, Moore and his colleagues performed calculations to determine if the Gaia space telescope had the necessary sensitivity to detect ultra-low frequency GWs.

To this end, Moore and his colleagues simulated gravitational waves produced by a binary supermassive black hole – i.e. two SMBHs orbiting one another. What they found was that by compressing the data sets by a factor of more than 10⁶ (measuring 100,000 stars instead of a billion at a time), GWs could be recovered from Gaia data with an only 1% loss of sensitivity.

Figure showing a Gaia star field, with red and black lines indicating induced apparent motions of the stars within a hemisphere. Credit: Kavli Institute for Cosmology, Cambridge

This method would be similar to that used in Pulsar Timing Arrays, where a set of millisecond pulsars are examined to determine if gravitational waves modify the frequency of their pulses. However, in this case, stars are being monitored to see if they are oscillating with a characteristic pattern, rather than pulsing. By looking at a field of 100,000 stars at a time, researchers would be able to detect induced apparent motions (see figure above).

Because of this, the full release of Gaia data (scheduled for the early 2020s) is likely to be a major opportunity for those hunting for GW signals. As Moore explained in a APS Physics press release:

“Gaia will make measuring this effect a realistic prospect for the first time. Many factors contribute to the feasibility of the approach, including the precision and long duration of the astrometric measurements. Gaia will observe about a billion stars over 5–10 years, locating each one of them at least 80 times during that period. Observing so many stars is the major advance provided by Gaia.”

It is also interesting to note that the potential for GW detection was something that researchers recognized when Gaia was still being designed. One such individual was Sergei A. Klioner, a researcher from the Lorhrmann Observatory and the leader of the Gaia group at TU Dresden. As he indicated in his 2017 study, “Gaia-like astrometry and gravitational waves“, Gaia could detect GWs caused by merging SMBHs years after the event:

“It is clear that the most promising sources of gravitational waves for astrometric detection are supermassive binary black holes in the centers of galaxies… It is believed that binary supermassive black holes are a relatively common product of interaction and merging of galaxies in the typical course of their evolution. This sort of objects can give gravitational waves with both frequencies and amplitudes potentially within the reach of space astrometry. Moreover, the gravitational waves from those objects can often be considered to have virtually constant frequency and amplitude during the whole period of observations of several years.”

*Artist’s impression of two merging black holes, which has been theorized to be a source of gravitational waves. Credit: Bohn, Throwe, Hébert, Henriksson, Bunandar, Taylor, Scheel/SXS*

But of course, there’s no guarantees that sifting through the Gaia data will reveal additional GW signals. For one thing, Moore and his colleagues acknowledge that waves at these ultra-low frequencies could be too weak for even Gaia to detect. In addition, researchers will have to be able to distinguish between GWs and conflicting signals that result from changes in the spacecraft’s orientation – which is no easy challenge!

Still, there is hope that missions like Gaia will be able to reveal GWs that are not easily visible to ground-based interferometric detectors like LIGO and Advanced Virgo. Such detectors are subject to atmospheric effects (like refraction) which prevent them from seeing extremely low frequency waves – for instance, the primordial waves produced during the inflationary epoch of the Big Bang.

In this sense, gravitational wave research is not unlike exoplanet research and many other branches of astronomy. In order to find the hidden gems, observatories may need to take to space to eliminate atmospheric interference and increase their sensitivity. It is possible then that other space telescopes will be retooled for GW research, and that next-generation GW detectors will be mounted aboard spacecraft.

In the past few years, scientists have gone from making the first detection of gravitational waves to developing new and better ways to detecting them. At this rate, it won’t be long before astronomers and cosmologists are able to include gravitational waves into our cosmological models. In other words, they will be able to show what influence these waves played in the history and evolution of the Universe.

Further Reading: Kavli Institute for Cosmology, APS Physics, Physical Review Letters

January 3, 2018January 3, 2018 by Matt Williams

In mid-March, the Chinese Tiangong-1 Space Station is Going to Come Crashing Back Down to Earth… Somewhere

Artist's illustration of China's 8-ton Tiangong-1 space station, which is expected to fall to Earth in late 2017. Credit: CMSE.

In September of 2011, China officially joined the Great Powers in Space club, thanks to the deployment of their Tiangong-1 space station. Since then, this prototype station has served as a crewed orbital laboratory and an experimental testbed for future space stations. In the coming years, China hopes to build on the lessons learned with Tiangong-1 to create a larger, modular station in 2023 (similar to the International Space Station).

Though the station’s mission was originally meant to end in 2013, the China National Space Agency extended its service to 2016. By September of 2017, the Agency acknowledged that they had lost control of the station and indicated that it would fall to Earth later in the year. According to the latest updates from satellite trackers, Tianglong-1 is likely to be reentering our atmosphere in March of 2018.

Given the fact that the station measures 10 by 3.35 meters (32.8 by 11 ft), weighs a hefty 8,506 kg (18,753 lb) and was built from very durable construction materials, there are naturally concerns that some of it might survive reentry and reach the surface. But before anyone starts worrying about space debris falling on their heads, there are a few things that need to be addressed.

*Images of the Tiangong-1 docking in Earth orbit in 2013. Credit: ESA*

For starters, in the history of space flight, there has not been a single confirmed death caused by falling space debris. Tthanks to the development of modern tracking and early warning systems, we are also more prepared than at any time in our history for the threat of falling debris. Statistically speaking, you are more likely to be hit by falling airplane debris or eaten by a shark.

Second, the CNSA has emphasized that the reentry is very unlikely to pose a threat to commercial aviation or cause any impact damage on the surface. As Wu Ping – the deputy director of the manned space engineering office – indicated at a press conference back on September 14th, 2017: “Based on our calculation and analysis, most parts of the space lab will burn up during falling.”

In addition, The Aerospace Corporation, which is currently monitoring the reentry of Tiangong-1, recently released the results of their comprehensive analysis. Similar to what Wu stated, they indicated that most of the station will burn up on reentry, though they acknowledged that there is a chance that small bits of debris could survive and reach the surface. This debris would likely fall within a region that is centered along the orbital path of the station (i.e. around the equator).

To illustrate the zones of highest risk, they produced a map (shown below) which indicates where the debris would be most likely to land. Whereas the blue areas (that make up one-third of the Earth’s surface) indicate zones of zero probability, the green area indicates a zone of lower probability. The yellow areas, meanwhile, indicates zones that have a higher probability, which extend a few degrees south of 42.7° N and north of 42.7° S latitude, respectively.

*The Aerospace Corporations predicted reentry for Tiangong-1. Credit: aerospace.org*

To add a little perspective to this analysis, the company also indicated the following:

“When considering the worst-case location (yellow regions of the map) the probability that a specific person (i.e., you) will be struck by Tiangong-1 debris is about one million times smaller than the odds of winning the Powerball jackpot. In the history of spaceflight, no known person has ever been harmed by reentering space debris. Only one person has ever been recorded as being hit by a piece of space debris and, fortunately, she was not injured.”

Last, but not least, the European Space Agency’s Inter Agency Space Debris Coordination Committee (IADC) will be monitoring the reentry. In fact, the IADC – which is made up of space debris and other experts from NASA, the ESA, JAXA, ISRO, KARI, Roscosmos and the China National Space Administration – will be using this opportunity to conduct a test campaign.

During this campaign, participants will combine their predictions of the reentry’s time window, which are based on respective tracking datasets obtained from radar and other sources. Ultimately, the purpose of the campaign is to improve prediction accuracy for all member states and space agencies. And so far, their predictions also indicate that there is little cause for concern.

As Holger Krag, the Head of ESA’s Space Debris Office, indicated in a press statement back in November:

“Owing to the geometry of the station’s orbit, we can already exclude the possibility that any fragments will fall over any spot further north than 43ºN or further south than 43ºS. This means that reentry may take place over any spot on Earth between these latitudes, which includes several European countries, for example. The date, time and geographic footprint of the reentry can only be predicted with large uncertainties. Even shortly before reentry, only a very large time and geographical window can be estimated.”

*The Chinese Long March 3 rocket reentering the atmosphere over Hawaii. Credits: ESA/Steve Cullen (Starscape Galery)*

The ESA’s Space Debris Office – which is based at the European Space Operations Centre in Darmstadt, Germany – will follow this campaign in February with an international expert workshop. This workshop (which will run from February 28th to March 1st, 2018) will focus on reentry predictions and atmospheric break-up studies and allow experts in the field of space debris monitoring to share their latest findings and research.

In the current age of renewed space exploration and rapidly improving technology, every new development in space is an opportunity to test the latest instruments and methods. The reentry of Tiangong-1 is a perfect example, where the reentry of a space station is being used to test our ability to predict falling space debris. It also highlights the need for tracking and monitoring, given that humanity’s presence in orbit is only going to increase in the coming years.

In the meantime, it would not be inadvisable to keep your eyes on the skies this coming March. While there is little chance that debris will pose a hazard, it is sure to be spectacular sight for people who live closer to the equator!

Further Reading: Aerospace.org, ESA, Xinhuanet

December 15, 2017December 17, 2017 by Matt Williams

Gaia Looks Beyond our Galaxy to Other Islands of Stars

Color view of M31 (The Andromeda Galaxy), with M32 (a satellite galaxy) shown to the lower left. Credit and copyright: Terry Hancock.

The European Space Agency’s (ESA) Gaia mission is an ambitious project. Having launched in December of 2013, the purpose of this space observatory has been to measure the position and distances of 1 billion objects – including stars, extra-solar planets, comets, asteroids and even quasars. From this, astronomers hope to create the most detailed 3D space catalog of the cosmos ever made.

Back in 2016, the first batch of Gaia data (based on its first 14 months in space) was released. Since then, scientists have been poring over the raw data to obtain clearer images of the neighboring stars and galaxies that were studied by the mission. The latest images to be released, based on Gaia data, included revealing pictures of the Large Magellanic Cloud (LMC), the Andromeda galaxy, and the Triangulum galaxy.

The first catalog of Gaia data consisted of information on 1.142 billion stars, including their precise position in the night sky and their respective brightness. Most of these stars are located in the Milky Way, but a good fraction were from galaxies beyond ours, which included about ten million belonging to the LMC. This satellite galaxy, located about 166 000 light-years away, has about 1/100th the mass of the Milky Way.

*Gaia’s view of the Large Magellanic Cloud. Click here for further details, full credits, and larger versions of the image. Credit: ESA/Gaia/DPAC*

The two images shown above display composite data obtained by the Gaia probe. The image on the left, which was compiled by mapping the total density of stars detected by Gaia, shows the large-scale distribution of stars in the LMC. This image also delineates the extent of the LMC’s spiral arms, and is peppered with bright dots that represent faint clusters of stars.

The image on the right, on the other hand, reveals other aspects of the LMC and its stars. This image was created by mapping radiation flux in the LMC and is dominated by the brightest and most massive stars. This allows the bar of the LMC to be more clearly defined and also shows individual regions of star-formation – like 30 Doradus, which is visible just above the center of the galaxy in the picture.

The next set of images (shown below), which were also obtained using data from the first 14 months of the Gaia mission, depict two nearby spiral galaxies – the Andromeda galaxy (M31) and its neighbor, the Triangulum galaxy (M33). The Andromeda galaxy, located 2.5 million light-years away, is the largest galaxy in our vicinity and slightly more massive than our own. It is also destined to merge with the Milky Way in roughly 4 billion years.

The Triangulum galaxy, meanwhile, is a fraction the size of the Milky Way (with an estimated fifty billion stars) and is located slightly farther from us than Andromeda – about 2.8 million light-years distant. As with the LMC images, the images on the left are based on the total density of stars and show stars of all types, while images on the right are based on the radiation flux of each galaxy and mainly show the bright end of the stellar population.

*Gaia’s view of the Andromeda galaxy. Credit: ESA/Gaia/DPAC*

Another benefit of the images on the right is that they indicate the regions where the most intense star formation is taking place. For many years, astronomers have known that the LMC boasts a significant amount of star-forming activity, forming stars at five times the rate of the Milky Way Galaxy. Andromeda, meanwhile, has reached a point of near-inactivity in the past 2 billion years when it comes to star formation.

In comparison, the Triangulum Galaxy still shows signs of star formation, at a rate that is about four and a half times that of Andromeda. Thanks to the Gaia images, which indicate the relative rates of star formation from elevated levels of radiation flux and brightness, these differences between Andromeda, Triangulum and the LMC is illustrated quite beautifully.

What’s more, by analyzing the motions of individual stars in external galaxies like the LMC, Andromeda, or Triangulum, it will be possible to learn more about the overall rotation of stars within these galaxies. It will also be possible to determine the orbits of the galaxies themselves, which are all part of the larger structure known as the Local Group.

This region of space, which the Milky Way is part of, measures roughly 10 million light-years across and has an estimated 1.29 billion Solar masses. This, in turn, is just one of several collections of galaxies in the even larger Virgo Supercluster. Measuring how stars and galaxies orbit about these larger structures is key to determining cosmic evolution, how the Universe came to be as it is today and where it is heading.

*The Triangulum galaxy (M33), based on data compiled by the Gaia mission. Credit: ESA/Gaia/DPAC*

An international team of astronomers recently attempted to do just that using the CosmicFlows surveys. These studies, which were conducted between 2011 and 2016, calculated the distance and speed of neighboring galaxies. By pairing this data with other distance estimates and data on the galaxies gravity fields, they were able to chart the motions of almost 1,400 galaxies within 100 million light years over the course of the past 13 billion years.

In the case of the LMC, another team of astronomers recently attempted to measure its orbit using a subset of data from the first Gaia release – the Tycho–Gaia Astrometric Solution (TGAS). Combined with additional parallax and proper motion data from the Hipparcos mission, the team was able to identify 29 stars in the LMC and measure their proper motion, which they then used to estimate the rotation of the galaxy.

Gaia’s observations of the LMC and the Small Magellanic Cloud (SMC) are also important when it comes to studying Cepheid and RR Lyrae variables. For years, astronomers have indicated that these stars could be used as indicators of cosmic distances for galaxies beyond our own. In addition, astronomers working at the Gaia Data Process ing and Analysis Consortium (DPAC) tested this method on hundreds of LMC variable stars in order to validate data from the first release.

Astronomers are eagerly awaiting the second release of Gaia data, which is scheduled for April of 2018. This will also contain measurements on stellar distances and their motions across the sky, and is expected to reveal even more about our galaxy and its neighbors. But in the meantime, there are still plenty of revelations to be found from the first release, and scientists expect to be busy with it for many years to come.

Further Reading: ESA

November 17, 2017November 19, 2017 by Matt Williams

When James Webb Finally Reaches Space, Here’s What it’ll be Hunting

Artist conception of the James Webb Space Telescope. Credit: NASA

Ever since the project was first conceived, scientists have been eagerly awaiting the day that the James Webb Space Telescope (JWST) will take to space. As the planned successor to Hubble, the JWST will use its powerful infrared imaging capabilities to study some of the most distant objects in the Universe (such as the formation of the first galaxies) and study extra-solar planets around nearby stars.

However, there has been a lot of speculation and talk about which targets will be the JWST’s first. Thankfully, following the recommendation of the Time Allocation Committee and a thorough technical review, the Space Telescope Science Institute (STScI) recently announced that it has selected thirteen science “early release” programs, which the JWST will spend its first five months in service studying.

As part of the JWST Director’s Discretionary Early Release Science Program (DD-ERS), these thirteen targets were chosen by a rigorous peer-review process. This consisted of 253 investigators from 18 counties and 106 scientific institutions choosing from over 100 proposals. Each program has been allocated 500 hours of observing time, once the 6-month commissioning period has ended.

*The JWST’s Optical Telescope element/Integrated Science instrument module (OTIS) undergoing testing at NASA’s Johnson Space Center. Credit: NASA/Desiree Stover*

As Ken Sembach, the director of the Space Telescope Science Institute (STScI), said in an ESA press statement:

“We were impressed by the high quality of the proposals received. These programmes will not only generate great science, but will also be a unique resource for demonstrating the investigative capabilities of this extraordinary observatory to the worldwide scientific community… We want the research community to be as scientifically productive as possible, as early as possible, which is why I am so pleased to be able to dedicate nearly 500 hours of director’s discretionary time to these early release science observations.”

Each program will rely on the JWST’s suite of four scientific instruments, which have been contributed by NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). These include the the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI) developed by the ESA, as well as the Near-Infrared Camera (NIRCam) developed by NASA and the STScI, and the Near-Infrared Imager and Slitless Spectrograph (NIRISS) developed by the CSA.

The thirteen programs selected include “Through the looking GLASS“, which will rely on the astronomical community’s experience using Hubble to conduct slitless spectroscopy and previous surveys to gather data on galaxy formation and the intergalactic medium, from the earliest epochs of the Universe to the present day. The Principal Investigator (PI) for this program is Tommaso Treu of the University of California Los Angeles.

*Once deployed, the JWST will conduct a variety of science missions aimed at improving our understanding of the Universe. Credit: NASA/STScI*

Another is the Cosmic Evolution Early Release Science (CEERS) program, which will conduct overlapping observations to create a coordinated extragalactic survey. This survey is intended to let astronomers see the first visible light of the Universe (ca. 240,000 to 300,000 years after the Big Bang), as well as information from the Reionization Epoch (ca. 150 million to 1 billion years after the Big Bang) and the period when the first galaxies formed. The PI for this program is Steven Finkelstein of the University of Texas at Austin.

Then there’s the Transiting Exoplanet Community Early Release Science Program, which will build on the work of the Hubble, Spitzer, and Kepler space telescopes by conducting exoplanet surveys. Like its predecessors, this will consist of monitoring stars for periodic dips in brightness that are caused by planets passing between them and the observer (aka. Transit Photometry).

However, compared to earlier missions, the JWST will be able to study transiting planets in unprecedented detail, which is anticipated to reveal volumes about their respective atmospheric compositions, structures and dynamics. This program, for which the PI is Imke de Pater from the University of California Berkeley, is therefore expected to revolutionize our understanding of planets, planet formation, and the origins of life.

Also focused on the study of exoplanets is the High Contrast Imaging of Exoplanets and Extraplanetary Systems program, which will focus on directly imaged planets and circumstellar debris disks. Once again, the goal is to use the JWST’s enhanced capabilities to provide detailed analyses on the atmospheric structure and compositions of exoplanets, as well as the cloud particle properties of debris disks.

*Artist’s impression of the planet orbiting a red dwarf star. Credit: ESO/M. Kornmesser*

But of course, not all the programs are dedicated to the study of things beyond our Solar System, as is demonstrated by the program that will focus on Jupiter and the Jovian System. Adding to the research performed by the Galileo and Juno missions, the JWST will use its suite of instruments to characterize and produce maps of Jupiter’s cloud layers, winds, composition, auroral activity, and temperature structure.

This program will also focus on some of Jupiter’s largest moons (aka. the “Galilean Moons”) and the planet’s ring structure. Data obtained by the JWST will be used to produce maps of Io’s atmosphere and volcanic surface, Ganymede’s tenuous atmosphere, provide constrains on these moons thermal and atmospheric structure, and search for plumes on their surfaces. As Alvaro Giménez, the ESA Director of Science, proclaimed:

“It is exciting to see the engagement of the astronomical community in designing and proposing what will be the first scientific programs for the James Webb Space Telescope. Webb will revolutionize our understanding of the Universe and the results that will come out from these early observations will mark the beginning of a thrilling new adventure in astronomy.”

During its mission, which will last for a minimum of five years (barring extensions), the JWST will also address many other key topics in modern astronomy, probing the Universe beyond the limits of what Hubble has been capable of seeing. It will also build on observations made by Hubble, examining galaxies whose light has been stretched into infrared wavelengths by the expansion of space.

*The James Webb Space Telescope’s 18-segment primary mirror, a gold-coated beryllium mirror has a collecting area of 25 square meters. Credit: NASA/Chris Gunn*

Beyond looking farther back in time to chart cosmic evolution, Webb will also examine the Supermassive Black Holes (SMBH) that lie at the centers of most massive galaxies – for the purpose of obtaining accurate mass estimates. Last, but not least, Webbwill focus on the birth of new stars and their planets, initially focusing on Jupiter-sized worlds and then shifting focus to study smaller super-Earths.

John C. Mather, the Senior Project Scientist for the JWST and a Senior Astrophysicist at NASA’s Goddard Space Flight Center, also expressed enthusiasm for the selected programs. “I’m thrilled to see the list of astronomers’ most fascinating targets for the Webb telescope, and extremely eager to see the results,” he said. “We fully expect to be surprised by what we find.”

For years, astronomers and researchers have been eagerly awaiting the day when the JWST begins gathering and releasing its first observations. With so many possibilities and so much waiting to be discovered, the telescope’s deployment (which is scheduled for 2019) is an event that can’t come soon enough!

Further Reading: ESA, STScI

November 11, 2017 by Matt Williams

NASA Moving Ahead with Deployment of Orion Capsule and Space Launch System

Artist concept of NASA’s Space Launch System (SLS) on the left, and the Orion Multi-Purpose Crew Vehicle (right). Credit: NASA

On October 11th, 2010, Congress signed the bipartisan NASA Authorization Act, which allocated the necessary funding for the space agency to commence preparations for its “Journey to Mars“. For the sake of mounting the first crewed missions to the Red Planet, several components were designated as being crucial. These included the Space Launch System (SLS) and the Orion Multi-Purpose Crew Vehicle.

Despite a recent announcement that NASA would be prioritizing a return to the Moon in the coming years, both the SLS and Orion are on track with the eventual goal of mounting crewed missions to Mars. In recent weeks, NASA conducted critical assessments of both components and their proposed launch schedules, and determined that they will be launched together in 2020 for the sake of conducting Exploration Mission-1 (EM-1).

This test flight, which will be uncrewed, will test both systems and lay the foundations for the first crewed mission of the SLS and Orion. Known as Exploration Mission- 2 (EM-2), which was originally scheduled for 2021, this flight is now expected to take place in 2023. EM-1 will also serve to establish a regular cadence of mission launches that will take astronauts back to the Moon and eventually on to Mars.

*NASA’s Orion spacecraft will carry astronauts further into space than ever before using a module based on Europe’s Automated Transfer Vehicles (ATV). Credit: NASA*

The recent review came on the heels of an earlier assessment where NASA evaluated the cost, risk and technical factors of adding crew to the mission. This review was initiated as a result of the crew study and the challenges related to building the core stage of the SLS. Foremost among these was the recent tornado damage caused to the Michoud Assembly Facility in New Orleans, where the SLS is currently being built.

On top of that, there are also the challenges related to the manufacture and supply of the first Orion Service Module. This module, which is being developed by the European Space Agency (ESA), serves as the Orion’s primary power and propulsion component, until it is discarded at the end of each mission. During the summer of 2016, the design of the Service Module was also the subject of a critical design review, and passed.

After conducting their review, NASA reaffirmed the original plan to fly the EM-1 uncrewed. As acting NASA Administrator Robert Lightfoot announced in a recent NASA press release:

“While the review of the possible manufacturing and production schedule risks indicate a launch date of June 2020, the agency is managing to December 2019. Since several of the key risks identified have not been actually realized, we are able to put in place mitigation strategies for those risks to protect the December 2019 date.”

In addition, NASA has established new production performance milestones to address a key issue identified by the review, which was scheduling risks. Based on lesson learned from first-time builds, NASA and its contractors have adopted new measures to optimize building plans which will ensure flexibility – specifically if contractors are unable to deliver on schedule.

At this juncture, NASA is on track to develop the new deep space exploration systems that will take astronauts back to the Moon and beyond. Cost assessments for EM-1, which include the SLS and ground systems, are currently within their original targets. By June 2020, NASA estimates that cost overruns will remain within a 15% limit for the SLS and just slightly above for the ground systems.

As part of the review, NASA also considered when the test of the Orion’s launch abort system (which needs to happen ahead of EM-1) would take place – which they chose to move up to April 2019. Known as Ascent-Abort 2, this test will validate the launch abort system’s ability to land the crew safely during descent, and ensure that the agency can remain on track for a crewed flight in 2023.

To build the SLS and Orion, NASA is relying on several new and advanced manufacturing techniques. These include additive manufacturing (3-D printing), which is being used to fashion more than 100 parts for the Orion spacecraft. NASA is also using a technique known as self-reaction friction stir welding to join the two largest core stages of the rocket, which are the thickest structures ever joined using this technique.

*Space Launch System (SLS) Block 1 Expanded View. Credit: NASA*

Integration of the first service module is well under way in Bremen, Germany, with work already starting on the second. This is taking place at the Airbus integration room, where crews on eight-hour shifts are busy installing more than 11 km (6.8 mi) of cables that will connect the module’s central computers to everything from solar planes and fuel systems to the module’s engines and air and water systems.

These crews also finished installing the Orion’s 24 orientation thrusters recently, which complement the eight larger engines that will back up the main engine. The complex design of the module’s propulsion system requires that some 1100 welds be completed, and only 173 remain. At present, the ESA crews are aiming to finish work on the Orion and ship it to the USA by the summer of 2018.

As far as the assembly of the SLS is concerned, NASA has completed welding on all the major structures to the rocket stages is on track to assemble them together. Once that is complete, they will be able to complete an engine test that will fire up the four RS-25 engines on the core stage simultaneously – the EM-1 “green run”. When EM-1 takes place, the launch will be supported by ground systems and crews at NASA’s Kennedy Space Center in Florida.

The agency is also developing a Deep Space Gateway (DSG) concept with Roscosmos and industry partners like Boeing and Lockheed Martin. This space station, which will be placed in orbit around the Moon, will facilitate missions to the lunar surface, Mars, and other locations deeper into the Solar System. Other components currently under consideration include the Deep Space Transport, and the Martian Basecamp and Lander.

These latter two components are what will allow for missions beyond the Earth-Moon system. Whereas the combination of the SLS, Orion and the DSG will allow for renewed lunar missions (which have not taken place since the Apollo Era) the creation of a Deep Space Transport and Martian Basecamp are intrinsic to NASA’s plans to mount a crewed mission to the Red Planet by the 2030s.

But in the meantime, NASA is focused on the first test flight of the Orion and the SLS, which will pave the way towards a crewed mission in a few years’ time. As William Gerstenmaier, the associate administrator for NASA’s Human Exploration and Operations Mission Directorate, indicated:

“Hardware progress continues every day for the early flights of SLS and Orion. EM-1 will mark a significant achievement for NASA, and our nation’s future of human deep space exploration. Our investments in SLS and Orion will take us to the Moon and beyond, advancing American leadership in space.”

For almost forty years, no crewed spaceflights have been conducted beyond Low-Earth Orbit. And with the retiring of the Space Shuttle Program in 2011, NASA has lost the ability to conduct domestic launches. For these reasons, the past three presidential administrations have indicated their commitment to develop the necessary tools to return to the Moon and send astronauts to Mars.

Not only will this restore the United State’s leadership in space exploration, it also will open up new venues for human exploration and create new opportunities for collaboration between nations and between federal agencies and industry partners. And be sure to check out this video showcases NASA’s plans for Deep Space Exploration:

Further Reading: ESA, NASA

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

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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