Two marbles sit on a midnight background, one a swirl of blue, white, brown and green, the other tinted in shades of grey. Together they are the Earth and her Moon as seen by the most powerful imagining system currently orbiting the planet Mars.
It is, in fact a composite image, although Earth and the Moon are the correct sizes and the correct position / distance relative to one another. The images were captured by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO) on November 26th, 2016.
The images were taken to calibrate HiRISE data, since the reflectance of the moon’s Earth-facing side is well-known. As such, this is not the first image of our home planet and its natural satellite captured from Martian orbit, but it is one of the most striking. Whilst a composite image, only the Moon’s brightness has been altered to enhance its visibility; were it to be shown at the same brightness scale as Earth, it would barely be visible. That it appears to be unnaturally close to Earth is in fact an illusion of perspective: at the time the pictures were taken, the Moon was on the far side of Earth relative to Mars, and about to pass behind it.
The image of Earth shows Australia prominent in the central area of the image, its shape just discernible in this high-resolution image, taken when Mars and the MRO were 205 million kilometres (147 million miles) from Earth.
For me, this is another picture demonstrating just how small, fragile and unique our home world actually is.
Falcon 9 Makes Triumphant Return to Flight
With Federal Aviation Authority (FAA) approval given, SpaceX, the private space company founded by Elon Musk, made a triumphant return to flight status with its Falcon 9 launch system on Saturday, January 14th.
SpaceX launches had been suspended in September 2016, after a Falcon 9 and its US $200 million payload were loss in an explosion during what should have been a routine test just two days ahead of the planned launch (see here for more). Towards the end of 2016, and following extensive joint investigations involving NASA and the US Air Force (The Falcon 9 was located at Launch Complex 40 at the Canaveral Air Force Station when the explosion occurred), SpaceX were confident they had traced the root cause for the loss to a failure of process, rather than a structural or other failure within the vehicle itself. However, they had to wait until the FAA had reviewed the investigation findings and approved the Falcon 9’s return to flight readiness before they could resume operations.
The January 14th launch came via the SpaceX West Coast facilities, again leased from the US Air Force, and saw a Falcon 9 booster lift-off from Space Launch Complex 4E at Vandenberg Air Force Base in California. The rocket was carrying the first ten out of at least 70 advanced Iridium NEXT mobile voice and data relay satellites SpaceX will launch over the coming months, as Iridium Communications place a “constellation” of 81 of the satellites in orbit around the Earth in a US $3 billion project.
All ten satellites were successfully lifted to orbit and deployed following a pitch-perfect launch, which had to take place at precisely 9:54:34 local time (17:54:34 UT) in order for all ten satellites to be correctly deployed to reach their assigned orbits. However, all eyes were on the Falcon 9’s first stage, which was set to make a return to Earth for an at-sea landing aboard one of the company’s two autonomous drone landing barges, Just Follow The Instructions.
Operating the Falcon 9 on a basis of reusability is core to SpaceX’s future plans to reduce the overall cost of space launches. While the company has previously made six successful returns and landings with the Falcon 9 first stage, this being the first attempt since September 2016’s loss added further pressure on the attempt. but in the event, it went flawlessly.
After separation from the upper stage carrying the payload to orbit, the first stage of the Falcon 9 completed what are called “burn back” manoeuvres designed to drop it back into the denser atmosphere. Vanes on the rocket’s side were deployed to provide it with stability so that it dropped vertically back down to Earth, using its engines as a braking system and deploying landing legs shortly before touchdown – and the entire journey was captured on video, courtesy of camera built-into the rocket’s fuselage.
On Monday, September 26th, after some teasing beforehand, NASA provided an update on the venting of water by Jupiter’s icy moon, Europa.
As I noted in my last Space Sunday report, Europa is covered by shell of water ice, much of it discoloured by mineral deposits and by deep cracks, beneath which it is believed to have a liquid water ocean about 100 km (62.5 miles) deep. The ocean is believed to be 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.
In 2012, The Hubble Space Telescope (HST) captured what appeared to be a huge plume of water erupting some 200 kilometres (125 mi) above the surface of Europa, using its Space Telescope Imaging Spectrograph (STIS) instrument. The update offered on September 26th provided information on further plumes, strengthening the case of water existing under the ice crust of Europa in the process – a crust which may be far thinner than thought.
Over a 15-month period, astronomers used Hubble’s STIS to observe Jupiter and Europa in the ultra-violet spectrum. During that time, Europa occulted (passed in front) of Jupiter on 10 separate occasions. The observations were an attempt to examine a possible extended atmosphere around the moon, which is slightly smaller than our own. However, on three of the passes, astronomers witnessed what appeared to be plumes of water erupting from the surface – and in pretty much the same location as seen in 2012. Analysis of the plumes revealed they were made up of hydrogen and oxygen consistent with water vapour being broken apart by Jupiter’s radiation in a process known as radiolysis.
The plumes are not constant, but rather flare up intermittently, possibly as a result of the surface ice on Europa flexing in response to the same gravitational influences that are keeping the ocean beneath the ice from freezing out. This suggests that the icy crust is, at least around the region where the plumes are occurring, thinner than had been thought. This is important, because it could mean that any automated mission sent to Europa could have a fair chance of cutting its way through the ice to deploy a submersible vehicle which could then search for any evidence of life in Europa’s salty ocean – which contains between two and three times as much water as all of Earth’s oceans combined.
The Gentle Crunch: Rosetta Mission Ends
The European Space Agency’s Rosetta spacecraft said farewell on Friday, September 30th, bringing the 12-year mission that bears its name to a close.
Launched in 2004, Rosetta was a daring attempt to rendezvous with a short-period comet, 67P/Churyumov-Gerasimenko, then orbit it and study it as it swept through the inner solar system and around the sun on its (roughly) 6-year obit. The aim was to give us unique insight into cometary behaviour and – more directly – to study one of these tiny lumps of mineral and chemical rich rock “left over” from the solar system’s formation, and thus gain greater understanding as to how things came to be, and perhaps how life itself might have begun.
Rosetta travelled almost 8 billion km (5 billion miles), including three flybys of Earth and one of Mars, and two asteroid encounters, before finally arriving at 67P/C-G in August 2014. In November of that year, The Philae lander was deployed in the hope of studying the comet from the surface and gathering samples of its material for analysis. Unfortunately, Philae’s anchoring mechanism failed, sending the little lander bouncing across the comet, until it came to rest in a location where it was receiving insufficient sunlight to recharge its batteries. Nevertheless, in the time it did have before its batteries were almost depleted, the washing machine sized lander some 80%+ of its science goals.
Meanwhile, Rosetta studied the comet in the long fall towards the Sun, and carried out an extensive mission of study, analysis and image capture, much of which has completely altered thinking around comets like 67P/C-G. For example, the mission discovered that water within the comet has a different ‘flavour’ to that of Earth’s oceans, suggesting that the impact of such comets with primordial Earth played far less of a role in helping start Earth’s oceans than had been thought.
As the comet became more active during its approach to the Sun, Rosetta found complex organic molecules – amino acid glycine, which is commonly found in proteins, and phosphorus, a key component of DNA and cell membranes – were present in the dust vented by 67P/C-G, reinforcing the idea that the basic building blocks for life may have been delivered to Earth from an early bombardment of such rocks. The mission also confirmed that the comet’s odd shape – two potato-like lobes of different sizes joined at a narrow waist – was the result of a very slow-speed collision very early in the comet’s 4.5 billion-year age.
In all the spacecraft operated in the harsh environment of the comet for 786 days, made a number of dramatic flybys close to its surface, survived several unexpected outgassings, and made two full recoveries for potentially serious “safe mode” situations. However, all things must inevitably come to an end, and with its manoeuvring propellants almost exhausted, on September 29th, Rosetta set course for a gentle crash landing on 67P/C-G.
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.
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.
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.
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.
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.
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.
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 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.
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 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.
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.
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.
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.
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.