Euorpa’s icy, mineral-stained surface as imaged by NASA’s Galileo mission – see below (credit: NASA / JPL)
NASA have been teasing the press and pundits with news that they have a “surprising” announcement to make about Europa, one of Jupiter’s four Galilean moons (so-called as they were first recorded by Galileo Galilei).
Slightly smaller than our own Moon, Europa is covered by shell of water ice, much of it discoloured by mineral deposits and by deep cracks. This icy surface might only be relative thin, on the order of a handful of kilometres in extent, or it might be tens of kilometres thick, and sits over an ocean which is mostly likely liquid water, although some argue it might actually be an icy slush, perhaps extending to 100 km (62.5 miles) in depth.
The ocean is made possible by tidal flexing enacted by the massive gravity of Jupiter as well as from the other large Galilean moons. This generates heat within Europa, and this heat stops the water from freezing solid.
An artist’s impression of how a huge plume of water, over 200km (125 mi) high, which erupted from Europa in 2012 and was “seen” by the Hubble Space Telescope, might have looked like if witnessed from the vicinity of Europa. Credit: NASA / ESA / M. Kornmesser.
Exactly how much heat is generated as a result of this flexing isn’t known, but it has been suggested that the ocean floor could be home to volcanic activity with hydrothermal vents and fumeroles responsible for pumping huge amounts of minerals into the water, as well as supplying energy, potentially marking Europa’s ocean as a place where basic microbial life might arise.
The discovery of life on Europa isn’t going to be the subject of the NASA press conference. It will instead reveal the findings of a Europa observation campaign using the Hubble Space Telescope linked to the potential for a liquid water ocean being present under the moon’s ice. I’ll likely have more next week.
Nor is Europa likely to be alone in harbouring a subsurface ocean among the Galilean moons of Jupiter. In 2015 data from the Hubble Space Telescope confirmed that Jupiter’s largest moon, Ganymede, has an underground ocean that contains more water than all of Earth’s combined. Hubble was used to carry out a spectrographic observation of Ganymede’s aurorae, displays of light in the atmosphere. Because aurorae are controlled by a moon or planet’s magnetic field, observing changes in how they behave offers insights into what is happening beneath the surface of the planet or moon. In Ganymede’s case, the aurorae allowed scientists to confirm a long-suspected subsurface salt water there.
Pluto’s Liquid Heart
A global mosaic of Pluto captured by New Horizons from a distance of 450,000 km (280,00 mi) from Pluto byt New Horizons on July 14th, 2015, coloured from data received by the RALPH instrument on the spacecraft, reveals the planet’s heart-shaped mark, the left “lobe” of which is formed by the massive depression dubbed “Sputnik Planum”. Credit: NASA/JPL / JHU/APL / SwRI
In June, I wrote about a paper proposing Pluto harbouring a liquid water ocean beneath its surface. The paper, by Planetary Science Institute Senior Scientist Amy C. Barr and Noah P. Hammond of Brown University, reached its conclusion after a prolonged study of Pluto’s geological features, including “Sputnik Planum”, a massive depression on the planetoid which forms one “lobe” of Pluto’s distinctive “heart”.
Barr and Hammond’s work focused on the lack of ice II on Pluto – a place where ice II should be expected to form. Had it done so, it would have caused volume contraction, resulting in the formation of compressional tectonic features on the surface of the planet. However, Barr and Hammond found no evidence for such features on Pluto in all of the images returned by the New Horizons spacecraft which flew past Pluto and its twin, Charon, in July 2015. This led them to conclude that Pluto’s interior is warmer than might be expected, which would both prevent ice II from forming and potentially give rise to a liquid ocean beneath Pluto’s frozen crust.
Now, a second paper has been published in Geophysical Research Letters, offering a suggestion as to how deep that ocean is, and its potential composition. Another research team at Brown University have been investigating the dynamics between Pluto and Charon, and the likely formation and development of the “Sputnik Planum” depression, which is thought to have been initially created by the impact of an object some 200 km (125 mi) across at some point in Pluto’s formative years.
Pluto and Charon are tidally locked with each other, so they always show each other the same face as they rotate. “Sputnik Planum” sits directly on the tidal axis linking the two worlds. This suggests the basin has what’s called a positive mass anomaly — it has more mass than average for Pluto’s icy crust. As Charon’s gravity pulls on Pluto, it would pull proportionally more on areas of higher mass, which would tilt the planet until “Sputnik Planum” became aligned with the tidal axis.
The surface ice on “Sputnik Planum” is constantly being renewed both by atmospheric deposition from above, and convection action from below, suggesting a source of heat beneath the ice, which in turn could be keeping any subsurface ocean liquid. Credit: NASA/JPL / JHU/APL / SwRI
But why would a crater – essentially a hole in the ground – be a positive mass anomaly? Part of the answer probably lies in the huge amount of nitrogen ice which has accumulated in the basin over the aeons, adding mass to the basin.
But the ice isn’t thick enough on its own to create the amount of mass needed to make “Sputnik Planum” have positive mass. Water, however, could have sufficient mass.
An impact creates a dent on a planet’s surface, followed by a rebound. That rebound pulls material upward from deep in the planet’s interior. If that material is denser than what was blasted away by the impact, the crater ends up with the same mass as it had before the impact happened. Any material added to it after the impact and rebound would therefore add mass to it, creating a positive mass anomaly.
The moment of destruction: the SpaceX Falcon 9 explodes on Launch Complex 40 at Kennedy Space Centre, Florida
SpaceX Look to Resume Falcon Flights in November 2016
SpaceX President Gwynne Shotwell has indicated the company hopes to resume Falcon 9 launches from November 2016, despite the September 1st loss of the launch vehicle and its US $200 million Amos 6 Israeli-built communications satellite during the preparations for a full static fire test of the rocket’s main engines.
It’s an ambitious aim, given that the cause of the loss is still unknown – and until it is known, it is highly unlikely the Falcon 9 will be cleared for flight by the FAA. However, the comments might suggest company feel that the cause of the loss may not have been with the booster itself, but may have been triggered by an external event, in which case such a target might be possible.
Launch Complex 40, Canaveral Air Force Station, after the Loss of the Falcon 9 booster and payload on September 1st, 2016. Credit: Ken Kremer
The static fire test is a part of pre-launch preparations unique to SpaceX. Basically a full dress rehearsal of a launch, it includes fuelling the booster and briefly firing the main engines with the rocket locked-down on the pad. It was during fuelling operations, eight minutes before the rocket motors were to be fired, the that a series of explosion occurred, destroying the booster and its payload.
Video footage seems to suggest the point of origin for the explosions was outside of the vehicle, in what SpaceX has called a “fast fire”, which started at, or near, the liquid oxygen fuelling umbilical. As well as the complete loss of the vehicle, the explosions and fireball caused extensive damage to Space Launch Complex (SLC) 40 at Canaveral Air Force Station, which had been leased to SpaceX for Falcon 9 launches.
It is the second lost of a Falcon 9 rocket in 15 months. In June 2015, the vehicle carrying the Dragon CRS-7 cargo resupply vehicle to the International Space Station disintegrated a little over two minutes after lift-off, following the failure of an internal strut.
In order to resume launches and meet obligations, SpaceX are planning on pivoting Falcon 9 launches to Kennedy Space Centre’s Pad 39A until such time as SLC 40 can be repaired. SpaceX leased the pad – a part of the complex used to launch the Saturn IB, Saturn V and space shuttles – in 2014 in a 20-year deal. It is currently being refurbished at the company’s expense to launch crewed Dragon 2 flights to the International Space Station, and commercial missions using their new Falcon Heavy launcher. Currently, there is still much work to be completed at the launch complex – previously used to launch the space shuttle, and before that, the mighty Saturn V rocket, although SpaceX plan to have the work completed by November.
Launch Complex 39A at Kennedy Space Centre undergoing refurbishment by SpaceX in preparation for Falcon Heavy and crewed Falcon 9 launches. The Rotating Service Structure, seen on the left and used for space shuttle launches, is due for demolition
Whether or not the root cause of the September 1st accident will be known by then, and the Falcon 9 cleared for flight is a major unknown. The investigations into the June 2015 loss took six months to complete and – due to it being caused by a failure within the vehicle – the rocket had to undergo several engineering changes.
Blue Origin Announces the New Glenn Booster Family
Blue Origin, the company founded by Amazon founder Jeff Bezos, revealed its plans for a family of reusable boosters for both orbital and deep space launches. Called New Glenn, the vehicles are a significant step forward for the company.
The New Glenn family. Credit: Blue Origin
Although more widely known for their efforts in the sub-orbital space tourism field, with their New Shephard reusable system, Blue Origin has long indicated it has wider aspirations, whilst remaining somewhat tight-lipped about exactly what it is developing.
Like the smaller New Shephard sub-orbital launch vehicle, New Glenn is to comprise a reusable first stage – referred to as the “propulsion module” on New Shepard. The vehicle has been under development for about 4 years, and the plan is for the first launch to take place in 2020.
Seven metres (23ft) in diameter, the New Glenn first stage will be powered by seven of the company’s new BE-4 engines. These are the same engines United Launch Alliance have selected as the primary propulsion unit for their own upcoming new Vulcan launch vehicle, which will enter service in 2019 to replace the expensive Atlas V booster.
This core stage of the new Blue Origin rocket – which is named for John Glenn, the first American to orbit the Earth, just as New Shephard is named after Alan Shephard, the country’s first astronaut to fly in space – will be topped by either a second stage for launches to low-Earth orbit, or a combination of a second stage and third stage system capable of a broader range of launch options. In both variants, the second stage will be powered by a single BE-4 engine, while the third stage will be powered by an uprated version of the BE-3 engine, currently used by the New Shephard. Neither the second nor third stages will be recoverable. It is anticipated that New Glenn will be capable of lifting between 35 to 70 tonnes to low Earth orbit, placing it in the same class of launch vehicle as SpaceX’s Falcon Heavy – and thus competing directly with it.
When it enters service, the new booster will be launched from America’s Space Coast, from the historic Space Launch Complex 36 at Canaveral Air Force Station, which Blue Origin took over in September 2015 in a deal with the USAF’s 45th Space Wing.
New Glenn compared to other current launch vehicles. The two-stage variant will be 85 metres (270ft) tall, and the 3-stage variant 95m (313 ft) tall. Both will have a 7m (23 ft) diameter. Credit: Blue Origin
In its time, SLC 36 was was used to launch the Mariner missions, the first US interplanetary probes to visit over worlds, Pioneer 10 and Surveyor-1, the first US vehicle to soft-land on the Moon. It was largely demolished in 2010, leaving just a single pad. Blue Origin are expected to construct a rocket fabrication and assembly facility there, as well as a new launch complex. Currently, it is not clear how the first stage of the booster will be recovered, but the company have hinted at an automated at-sea landing in the style of SpaceX might be used.
China Launches Tiangong-2
On Thursday, September 15th, 2016, and as expected, China launched the Tiangong-2 (“Heavenly Palace 2”) orbital laboratory from their Jiuquan Satellite Launch Centre in Gansu Province, and on the edge of the Gobi Desert in northern China. The Long March 2F booster (and not a long March 7, as incorrectly reported in some space news outlets) lifted-off at 14:04 UTC, making for a night launch, local time.
The Long March 2F carrying the Tiangong-2 orbital laboratory, lifts-off from China’s Jiuquan Satellite Launch Centre in Gansu Province at 14:04 UTC on Thursday, September 15th
Tiangong-2 is the second phase of China’s goal to establish a permanently crewed space station in the early to mid 2020s. This work started in 2011 with the launch of the Tiangong-1 facility, which was briefly visited by two crews in 2012 and 2013. It will culminate in the on-orbit construction of a large space station, starting with the launch of the Tianhe (“Harmony of the Heavens”, and formerly Tiangong-3) space station core module in 2022.
an artist’s impression of Tiangong-2 (centre right) with the Tianzhou resupply vehicle docked (left), together with the Shenzhou-12 crew vehicle at the laboratory’s far docking port. Credit: CCTV
It is expected that at least two crews will visit the facility. The first 2-person crew will fly to the laboratory in October aboard Shenzhou-11. They will commence the first round of a fairly extensive science programme, remaining at the lab for around 30 days.
After this, the facility will be left dormant until April 2017, when a Long March 7 booster is due to deliver the Tianzhou (“Heavenly Ship”) uncrewed resupply vehicle to orbit. This craft will then perform an automated docking with Tiangong-2, providing it with additional fuel, water and other consumables and also use its engine to boost the laboratory into a higher orbit to await the arrival of the second crew.
The second crew, comprising 3 personnel, should fly to the facility in mid-2017 Shenzhou-12. They are expected to say for less than 30 days, but while there carry out a number of tasks connected to developing a full space station, including performing an EVA. Whether further crews will visit the station after this has yet to be determined.
A Billion Stars – A Map to Our Galactic Neighbourhood
The first one billion: a billion stars in our galaxy mapped by distance and brightest – with a few extra-galactic objects shown for good measure. Credit: ESA/Gaia/DPAC
The above image might not look like much, but it is the largest all-sky survey of celestial objects published to date, pinning down the precise position on the sky and the brightness of 1142 million stars in our galaxy.
It is the product of the European Space Agency’s (ESA) Gaia Project, which is approaching the mid-point in its 5-year mission. Launched in December 2013, and orbiting the L2 Lagrange point, Gaia commenced its mapping operation in July 2014 – and it will continue doing so through until 2017. This map, released by the European Space Agency on September 14th, covers the data gathered from July 2014 through to September 2015. A further map, which includes data through to August 2016, is currently in development.
An artist’s impression of the Gaia vehicle at the L2 position relative to the Earth and Sun
The intention is to create a precise three-dimensional map of astronomical objects throughout the Milky Way, mapping their motions, which reflect the origin and subsequent evolution of the galaxy. Spectrophotometric measurements by the craft will provide a detailed survey of all observed stars, characterising their luminosity, effective temperature, gravity and elemental composition. The data gathered will provide the basic observational data to tackle a wide range of important questions related to the origin, structure, and evolutionary history of our galaxy.
It is the second such survey to be undertaken. The first was ESA’s Hipparcos mission, almost two decades ago, which surveyed around 200 million stars. One aspect of the Gaia survey will be to compare its findings with those of Hipparcos, so it will hopefully be possible to start disentangling the effects of “parallax”, a small motion in the apparent position of a star caused by Earth’s yearly revolution around the Sun, and the “proper motion” of the star’s physical movement through the galaxy.
The Gaia map includes globular clusters without our own galaxy, and images of clusters and galaxies beyond our own. Credit: ESA/Gaia/DPAC
The Gaia map means it is now possible to measure the distances and motions of stars in about 400 clusters up to 4,800 light-years away, and includes 3194 variable stars, which rhythmically swell and shrink in size, leading to periodic brightness changes. Many of these are located in the Large Magellanic Cloud, one of our galactic neighbours, a region that was scanned repeatedly during the first month of observations, allowing accurate measurement of their changing brightness. During the first phase of the mission, Gaia also discovered its first supernova in another galaxy, and the science and engineering team had to overcome a “stray light” issue where fibres used in the vehicle’s sun shield protrude beyond the edges of the shield and into the field of view. In doing so, they reflect unwanted light, resulting a degradation in science performance when mapping the faintest of stars in Gaia‘s view.
The Birth of a Black Hole?
Black holes; the boogie-men of the cosmos. Deep wells of gravity so intense that not even light can directly escape after passing the event horizon. They are formed in one of two ways, during the death of super-massive stars.
In the first, the star gobbles up the last of its fusionable fuel, causing the core to suddenly and violently contract, in turn triggering a violent explosion – a supernova – completely shedding the star’s outer shell of mass, and leaving behind a super-dense neutron star. Generally only 10 or so kilometres across, this have a greater mass than our Sun. It is thought that if this mass is too great, the neutron star also collapses in on itself, forming a black hole. In the second, the star doesn’t go supernova, but experiences a “failed supernova” brightening for a very brief period as some matter is lost, but then continuing to collapse in on itself until a black hole is formed. In both cases, the star vanishes from the visible spectrum, leaving behind tell-tale signs in the infra-red and in x-rays.
The Large Binocular Telescope, one of three instruments so far used in gathering data on N6946-BH1. Credit: NASA
A team of astronomers now believe they have captured the birth of a black hole through this second process.
They were studying data relating to N6946-BH1, a red giant thought to be coming to the end of its life, when they noticed something odd. In 2009 the star, roughly 25 times bigger than our Sun and 20 million light years away, could be seen in the visible light wavelengths. By 2015, however, it had vanished, leaving only an infra-red afterglow. A subsequent check on Hubble Space Telescope data revealed the same: in 2007 the star was visible, in 2015, it wasn’t.
Intrigued, the team checked data on the star from the Palomar Transit Factory (PTF). This revealed that in 2009, N6946-BH1 blossomed briefly in luminosity, with a massive burst of neutrinos occurring at the same time – events both consistent with the star collapsing, but not going supernova. Add these to the infra-red tell-tale, and it would seem N6946-BH1 might have formed a black hole.
If so, it should now be a source of x-rays emitted in a particular spectrum as local matter fails into it. The team are now hoping that the Chandra X-ray Observatory in Earth orbit will be able to take a look at N6946-BH1 in the next two months or so to see if those x-rays can be detected. Should it be determined that N6946-BH1 has collapsed into a black Hole – even one now 20 million years old – studying it could help describe the beginning of the life cycle of a black hole, and better inform us on how black holes form, potentially why some super-massive stars form a neutron star rather than collapsing all the way to a black hole.
A dramatic look back: in the foreground is the lower slope of one of the “Murray Buttes”, in the far distance the tall peaks of Gale Crater’s huge rim. One of a series of images taken by NASA’s Curiosity rover on Thursday, September 8th, the rover’s 1,454 sol on Mars. Credit: NASA/JPL / MSSS
NASA’s Mars Science Laboratory rover, Curiosity, has said “farewell” to “Murray Buttes” in a stunning series of images, as it continues its climb up the slopes of “Mount Sharp”, a massive mound of deposited material located at the central impact peak of Gale Crater.
The mesas of “Murray Buttes” mark the upper extend of the transitional “Murray Formation”, where the material deposited during the earliest centuries of “Mount Sharp’s” formation merge with the rock comprising the crater floor. Curiosity has been passing by the area of the buttes for a little over a month now, carrying out examinations of the rock surface and gathering samples of mudstone for analysis.
“Murray Buttes” with the faint outlines of Gale Crater beyond, as images on Thursday, September 8th 2016, by NASA’s Curiosity rover during its 1,454 sol on Mars. Credit: NASA/JPL / MSSS
Believed to be the eroded remnants of ancient sandstone that originated when winds deposited sand after lower “Mount Sharp” had formed, the buttes rival anything of a similar nature found on Earth in terms of dramatic looks and structure. So much so that while we’re hardly likely to see Clint Eastwood ride his horse around the base of one, they would nevertheless fit neatly into a Sergio Leone western.
Several of the pictures – mosaics of images captured by the rover which have been white-balanced to match typical Earth daylight lighting conditions and then stitched together to offer complete scenes – reveal the deeply layered nature of the sandstone, sandwiched in what is referred to as “cross-bedding”. This indicates that the formations are the result of both wind deposition of material and then wind erosion, further confirming the idea that “Mount Sharp” was initially formed as a formed as a result of Gale Crater once being home to a great lake, before the waters receded and wind action took over.
A closer view of the layered nature of the sandstone deposits forming “Murray Buttes”, showing the “cross bedding” of the layers, indicative of the role that wind played in their deposition / formation. This picture comprises a mosaic of images captured by Curiosity rover on Thursday, September 8th, 2016 during its 1,454 sol on Mars. Credit: NASA/JPL / MSSS
The images were taken as Curiosity traversed the base of the final butte, where it gathered a final drilling sample on September 9th. On completion of the sample-gathering, the rover will continue farther south and higher up Mount Sharp, leaving these spectacular formations behind.
Curiosity’s route up the slopes of “Mount Sharp” – click for full size. Credit: T.Reyes / NASA/JPL
The Sand Dunes of Shangri-La
On September 7th, NASA issued a video showing the latest radar images captured by the Cassini probe of the surface of Saturn’s largest moon, mighty Titan. The data was gathered as the probe swept by the huge moon – which is blanketed by a thick atmosphere and is known to have lakes and rivers of liquid hydrocarbons on its surface – at a distance of some 976 km (607 mi) on July 25th, 2016 – one of the closest passes over the moon the vehicle has ever made.
Because of the moon’s thick atmosphere, conventional camera systems cannot be used to probe Titan’s mysteries, so Cassini uses a radar system to “map” surface features in black-and-white. Of particular interest to mission scientists during the July 25th flyby was a dark patch along Titan’s equator, previously images by the radar system at much greater distances and dubbed “Shangri-La”. And area which revealed itself to be – in part – a region of linear dunes, mostly likely comprised of grains derived from hydrocarbons that have settled out of Titan’s atmosphere, and which have been sculpted by Titan’s surface winds. Scientists can use the dunes to learn about winds, the sands they’re composed of, and highs and lows in the landscape.
Also captured by the radar is an arena dubbed “Xanadu annex”, believed to be an out-thrust of chaotic terrain from a region dubbed “Xanadu” just to the north of “Shangri-La”. First imaged by the Hubble Space Telescope in 1994, just before the Cassini / Huygens mission was launched, “Xanadu” and its annex are thought to be remnants of the moon’s icy crust before it was covered by organic sediments from the atmosphere.
OSIRIS-REx Lifts-off as an Asteroid Sweeps By Earth
On Thursday, September 8th, NASA successfully launched OSIRIS-REx on a 7-year trek to reach asteroid Bennu, where it will gather surface samples and return them to Earth for analysis. The mission, which I previewed in my last Space Sunday report, lifted-off flawlessly from Space Launch Complex 41 at Cape Canaveral Air Force Station at 19:05 EDT, atop its Atlas V booster at the start of a journey which will carry it a total of 7.2 billion kilometres (4.5 billion miles).
The Atlas V booster carrying OSIRIS-REx shortly after lift-off on Thursday, September 8th. Credit: Ken Kremer
Witnessing the launch was principal investigator Dante Lauretta, from the University of Arizona. “I can’t tell you how thrilled I was this evening, thinking of the people who played a part in this,” he said following the launch.
“This represents the hopes and dreams and blood, sweat and tears of thousands of people who have been working on this for years.”
The mission will gather samples from the surface of the asteroid – a remnant from the formation of the solar system – and will also map Bennu’s orbit around the Sun and the influences affecting it.
This is because the asteroid is a near-Earth object (NEO): an asteroid which periodically passes across Earth’s orbit around the Sun, and can come very close to our planet whilst doing so. So close, in fact, that some estimates of Bennu’s future orbit suggest it will collide with Earth towards the end of the next century.
July 14th: Jupiter with Io, Europa and Ganymede as seen by Juno after the craft had finished its critical engine burn to slip into a 53.5 day orbit around the giant planet. Juno will once again skim Jupiter’s cloud tops on Saturday, August 27th. Credit: NASA / JPL; SwRI / MSSS
NASA’s Juno mission to Jupiter is swinging back in towards the gas giant, on route to complete the first of some 37 planned polar orbits of the planet between now and February 2018 which are designed to probe the mysteries of the giant planet as never before.
As I reported in early July, the Juno space vehicle arrived at Jupiter on July 4th, where it completed a critical burn of its UK-built Leros-1b engine to ease its way into a highly elliptical orbit around Jupiter after a voyage of 2.8 billion km (1.74 billion miles) and 5 years, during which the craft first looped out past the orbit of Mars before falling back towards Earth to pick up a “gravity assist” to accelerate it on to its rendezvous with Jupiter.
The July 4th braking manoeuvre placed Juno in an orbit which, at its closest to Jupiter, skims just a few thousand kilometres above the planet’s cloud tops, and at its furthest sees Juno over 3 million kilometres from the planet. That first braking manoeuvre was undertaken with the probe’s science systems powered-down as a precautionary measure, and were powered-back up a few days after closest approach.
On August 27th, the vehicle will complete the first of these 53.5-day during “long” orbits, once again passing to within 4,200 km (2,600 mi) of Jupiter’s cloud tops at the equator, after arcing down over the planet’s north pole – and this time, all of the science instruments will remain operational, including JunoCam, the vehicle’s imaging system.
JunoCam has actually be in continuous operation in ” marble movie” mode since July 11th, 2016, capturing 5 full-colour images per hour, watching Jupiter spin from a distance (a sample of this movie is embedded blow – not Jupiter’s spin is greatly speeded-up). However, Jupiter is so small in most of the images – just 50 pixels across – that these haven’t been a source of interest to the media. As Juno approaches Jupiter on August 27th, however, the imaging system will switch from “marble movie” mode to gathering images at a higher rate to fully capture the close flyby as the craft passes over Jupiter’s north pole, curls around the planet north-to-south, before heading back out into space once more on the second of its “long” orbits.
JunoCam has a relative narrow field of view, so the images it captures on August 27th will be tightly focus on Jupiter’s clouds, and not as panoramic as those we’re been accustomed to seeing from the Hubble Space Telescope and from the now defunct Galileo mission. But they should still hopefully prove spectacular.
The next time Juno makes a close approach to Jupiter after this will be on October 19th. At that time, the science instruments will again be powered-off while the craft makes a second orbital burn, this time to reduce its orbit around Jupiter of 53.5 days to just 14 days, allowing the primary science mission to start.
This is intended to improve our understanding of Jupiter’s formation and evolution. The spacecraft will investigate the planet’s origins, interior structure, deep atmosphere and magnetosphere. Juno’s study of Jupiter will help us to understand the history of our own solar system and provide new insight into how planetary systems form and develop in our galaxy and beyond. It will also, for the first time, allow us to “see” below Jupiter’s dense clouds.
Selling the ISS?
This past week, NASA hosted a Journey to Mars showcase, looking at the space agency’s plans for developing the means to send humans to Mars in the 2030s. The actual plans for doing so are still pretty nebulous, but much of in revolves around the current development of the Orion Multi-Purpose Crew Vehicle (MPCV) and its supporting systems (including deep-space habitat modules), and the rocket system which will be used to launch it, the Space Launch System (SLS).
This being the case, the event was hosted at NASA’s Michoud Assembly Facility in New Orleans, where the core stage of the SLS vehicle the Orion MPCV. Included in the event was a trip to see a further test firing of one of the RD25 engines which will power the SLS at launch, and were previously used to power the space shuttle during its ascent to orbit.
However, what particularly grabbed the attention of the media was the announcement that the space agency is looking to sell the International Space Station to a private entity or entities in the mid-2020s, under the understanding that said entity/ies will keep the station active and continue to allow NASA to have access to it.
The move is a bold one. Currently, the ISS is the biggest single component of NASA’s budget, (just over US $3 billion in 2016 and projected to pass US $4 billion in 2020), and is only funded through until 2024. Thus, selling it to a private concern, could allow NASA to continue to make use of the station for research purposes beyond 2024 without having to meet all of the hefty costs involved in actually operating the station, potentially freeing-up some of the money dedicated for ISS support for use elsewhere.
Quite who would be willing to buy the ISS – both SpaceX and Boeing are apparently on NASA’s list of potential interested parties, although the interest may not be reciprocal – and quite how NASA’s international partners feel about the idea, is unclear.
August 2016 sees NASA’s Mars Science Laboratory rover Curiosity rack up four (terrestrial) years of operations on the surface of Mars.
The rover marked this anniversary rather quietly, by preparing to take further rock samples, this time from a target dubbed “Marimba”. Once gathered, the samples will be subjected to on-board analysis by Curiosity using the compact laboratory systems contained the rover’s body.
The sampling take place as the rover is engaged in a multi-month ascent of a mudstone geological unit as it continues its climb towards higher and progressively younger geological areas on “Mount Sharp” (more correctly, Aeolis Mons), which will include some rock types not yet explored.
August 2nd, 2016 (Sol 1,418)T: the Navigation Camera (Navcam) on Curiosity’s mast images the rover’s extended robot arm over a section of the “Marimba” target rock, ready to use the wire brush mounted on the “hand” at the end of the arm in order to scour surface material which otherwise might contaminate and samples gathered from the rock, prior to the rover taking a drilling sample. Credit: NASA/JPL / MSSS
In the meantime, examining the samples gathered from “Marimba” will allow a direct comparison with mudstone samples gathered further down the slopes of “Mount Sharp” and from the flatlands of Gale Crater. This will enable scientists to build a more complete picture of the mineral and chemical environment the rover is travelling through, and so further understand the general conditions which may have once have existed within the crater.
Goodnight from a Lunar Jade Rabbit
China has finally bid farewell to Yutu (“Jade Rabbit”, named for the companion to the Moon goddess Chang’e), its first lunar robotic explorer, after 31 months of surface operations.
The little solar-powered rover arrived on the lunar surface as part of Chain’s Chang’e 3 lander / rover mission on December 13, 2013, and was deployed from the lander some 7.5 hours after touch-down.
Yutu as imaged from the Chang’e 3 lander (part of the solar panel from which can be seen in the lower right corner). Credit: National Astronomical Observatories of China
However, due to the vast temperature differential experienced between the sunlit and shadowed parts of the rover at the time of the landing, operations didn’t commence until December 21st, when the rover was uniformly lit by the Sun. It’s first activity was to drive part-way around its parent lander and photograph it. After this, the rover travelled some 40 metres (130 ft) from the lander to commence independent science operations studying the lunar surface.
Yutu was designed to operate for just three months and travel up to 10 km (6.2 mi) within an area of 3 square kilometres (1.2 sq mi). Following its expose to the first 14-day long lunar “night”, the rover resumed operations in January 2014. However, as the second lunar night period approached (lasting 14 terrestrial days), the rover suffered a glitch in its drive mechanisms, leaving it susceptible to the harsh cold of the night-time, and on February 12th, following its second Lunar night, the rover was declared lost … only to resume communications with Earth within 24 hours.
Since that time, although immobilised, the little rover has maintained almost regular contact with Earth, but with each night period taking an increasing tolls on its systems. Even so, its continued survival gained it a huge and loyal following on the Chinese micro-blogging site, Weibo, where in a leaf firmly pulled from NASA’s book of social media engagement, Yutu had a first-person account.
It was via that social media account that Yutu’s final demise was announced, as if from the rover itself, on August 2nd 2016:
This time it really is goodnight. There are still many questions I would like answers to, but I’m the rabbit that has seen the most stars. The Moon has prepared a long dream for me, I don’t know what it will be like – will I be a Mars explorer, or be sent back to Earth?
The message gained a huge response from the rover’s 600,000 followers, and the Chinese space agency officially confirmed the rover had “died”, on Wednesday, August 3rd.
SpaceX’s plan to start down the road to their first human mission to Mars with their 2018 automated mission to the Red Planet – which NASA suggests will cost the company around US $320 million
NASA has indicated that the SpaceX Red Dragon mission to Mars, which the company plans to carry out in 2018, will likely cost around US $320 million for SpaceX to mount, ad NASA itself will spend around US $32 million over four years in indirect support of the mission.
The Red Dragon mission, first announced in April 2016, will be financed entirely by SpaceX; NASA’s costs will be related to providing technical and logistical support – such as using its Deep Space Tracking Network for communications with the vehicle.
If all goes according to plan, the Red Dragon mission could be launched as early as May 2018. It is the crucial first step along the road towards the company’s ambitions to land a human crew on Mars by the end of the 2020s. If successful, it could potentially be followed by at least three further uncrewed Red Dragon flights in 2020/22, prior to the company commencing work on building-up matériel on Mars in preparation for a crewed mission.
A SpaceX / NASA infographic outlining the 2018 mission. Credit: NASA / SpaceX
Red Dragon is the name of an uncrewed variant of the SpaceX Dragon 2 vehicle, which will enter service in 2018 ferrying astronauts to / from the International Space Station. Intrinsic to the mission is the plan to conduct a propulsive landing on Mars using the craft’s SuperDraco Descent Landing capability. This is vital on two counts.
For SpaceX, a crewed variant of the Red Dragon will likely be the Mars descent / ascent vehicle during a human mission to the planet. So understanding how it operates in the Martian atmosphere is a vital part of preparing to land a crew on the planet. NASA is similarly interested in learning how well retropropulsion works in slowing a vehicle to subsonic speeds in the Martian atmosphere, as it now looks likely they will use the same approach for their human missions to Mars, which may occur in the 2030s. Gaining the data from the SpaceX missions means that NASA doesn’t have to fly its own proof-of-concept missions all the way to Mars.
A Dragon 2 text article test-fires its eight SuperDraco engines during a hover test in 2014
Whether or not Red Dragon will fly in 2018 is still a matter of debate. SpaceX has some significant commitments and obligations on which to focus: commercial Falcon launches, resupply missions to the ISS, the start of crewed flights to the ISS, introducing the Falcon 9 into its flight operations, etc. These all tend to suggest that the development of the Red Dragon capsule, which will require some significant modifications when compared to the Dragon 2, will be subject to the company’s existing commitments taking priority over it.
In the meantime, the company plans to release more information on the overall Mars strategy, up to and including their human mission, in September.
Jupiter’s Great Red Spot: Atmospheric Heating for a Giant
As the Juno space vehicle reached the farthest point from Jupiter in its first orbit around the gas giant and begins a 23-day “fall” back towards the planet, scientists on Earth may have unlocked the secret of why Jupiter’s upper atmosphere is so warm.
The Eye of Jupiter: a CGI recreation of the Great Red Spot based on observations from the Voyager spacecraft and Hubble Space Telescope, and as used in the television series Cosmos: A Spacetime Odyssey. Credit: 21st Century Fox.
Here on Earth, the atmosphere is heated by the Sun. However, despite being five times further from the Sun than Earth, the upper reaches of the Jovian atmosphere share similar average temperatures to our own when they should in fact be a lot colder. Many theories have been put forward as to why this is the case, but now a team from Boston University, Massachusetts, believe they’ve found the answer: the heating of Jupiter’s upper atmosphere is the combined result of the Great Red Spot (GRS) and Jupiter’s aurorae.
The Great Red Spot is one of the marvels of our solar system. Discovered within years of Galileo’s introduction of telescopic astronomy in the 17th Century, it is a swirling pattern of red-coloured gases thought to be a hurricane-like storm raging down through the centuries in the Jovian atmosphere. Roughly 3 Earth diameters across, its winds take six days to complete one spin around its centre, driven in part by Jupiter’s own high-speed spinning about its own axis, completing one revolution every ten hours.
Inara Pey: Living in a Modemworld