Space Sunday: other worlds, near and far

Curiosity on “Mount Sharp” as seen by the Mars Reconnaissance Orbiter. Credit: NASA/JPL / MSSS  (click for full size)

NASA’s Mars Science Laboratory rover, Curiosity continues to climb Aeolis Mons (“Mount Sharp”), and in doing so, it has been once again imaged from orbit by the HiRISE camera system on NASA’s Mars Reconnaissance Orbiter (MRO). The image was captured on June 5th, 2017 (Curiosity’s 1717th Martian Sol), at the same time the rover was engaged in taking colour images of its surrounding using its mast-mounted Navcam system.

MRO has actually been imaging Curiosity roughly once every three months, as the orbiter’s track around Mars carries it over “Mount Sharp” and the rover’s route up the mound’s flank. However, these aren’t simply happy snaps of the rover’s progress: MRO is actively monitoring the terrain around the rover to allow scientists to check for changes – such as movement among sand dunes – and to help plan the rover’s route up the slopes.

The June 5th image, released by NASA on June 20th, has been colour enhanced to better reveal Curiosity as a bright blue feature. To give an idea of scale and resolution, the rover is some 3 metres (10ft) in length and 2.8 metres (9 ft) wide.

A mosaic of images captured by Curiosity using the Navcam system, looking back along the rover’ route up “Mount Sharp” towards the distant rim of Gale Crater. The images making up the view were all captured on June 5th, 2017 (Sol 1717 for the rover), the same day as MRO imaged the rover from orbit. Credit: see image

Curiosity is currently traversing ground between two points of scientific interest: the “Bagnold Dunes”, an area of sand dunes which are slowly progressing down the side of “Mount Sharp” as a result of both wind action and gravity; and a high-standing ridge which runs parallel to the eastward side of the dune field. Dubbed the “Vera Rubin Ridge” after the American astronomer who pioneered work on galaxy rotation rates, this ridge line is of interest to scientists because it has been shown to exhibit signatures of hematite, an oxidized iron mineral which can provide clues to the environmental conditions on this region of “Mount Sharp” when it formed.

The route to the ridge is slightly circuitous. At the moment the rover is heading east-north-east around a small set of dunes. Once clear of them it will turn south-east and drive to where a potential safe route up onto the ridge has been identified. The drive is further slowed as Curiosity periodically pauses to capture images of the feature to help scientists characterize any observed layers, fractures, or geologic contacts and better understand determine how the ridge formed, and its relationship to the other geologic units found within Gale Crater.

The route ahead: a June 14th (Sol 1726) mosaic captured by Curiosity, showing “Vera Rubin Ridge”, which was roughly 370 metres (114 ft) away from the rover at the time the images were captured. Credit: NASA/JPL / MSSS / Ken Kremer / Marco DiLorenzo

At the same time NASA released the image of Curiosity seen from orbit, half a world away, attempts to correct a wheel problem the solar-powered Opportunity Mars Exploration Rover (MER) had been experiencing appeared to end in partial success.

“Oppy” had suffered a failure with its left-front wheel steering actuator on June 4th, leaving the wheel angled and unable to straighten. After numerous attempts to correct the issue, a new approach tested on June 20th resulted in the wheel turning correctly and resuming its proper alignment with the other wheels. However, what originally caused the actuator to fail remains unknown, and there is concern that it might recur.

To limit the risk of this happening and possibly stranding “Oppy”, the rover will avoid all use of its front wheel steering, and will only use its rear wheel steering when absolutely necessary. To maintain manoeuvrability, it will instead rely on “tank steering” – effectively running the drive motors for the wheels on one side of the rover in opposition to those on the other, allowing Opportunity to turn left or right more-or-less on the spot, a technique the rover is designed to use. This should allow the rover to continue its current survey of “Perseverance Valley” in preparation for a descent into Endeavour Crater.

“Planet Nine” Set to Become “Planet Ten”?

I’ve written extensively in these pages about the hunt for “Planet Nine” (or “Planet X” or “George”, “Jehoshaphat” or “Planet of the Apes” as some would have it): the Neptune-sized world believed to be orbiting the sun at a distance of at least 200 astronomical units (AUs – one AU being the average distance of the Earth from the Sun) in a highly eccentric orbit.  The search for that world is still continuing, but if a new study is confirmed, that mystery world may well have to give up its “Planet Nine” title for another.

A planetary mass object the size of Mars would be sufficient to produce the observed perturbations in the distant Kuiper Belt. Credit: Heather Roper/LPL

Kat Volk and Renu Malhotra of the University of Arizona’s Lunar and Planetary Laboratory, offer compelling evidence of a yet-to-be-discovered planetary body with a mass somewhere between that of Mars and Earth, orbiting the Sun much closer than the mysterious “Planet Nine”, at around 50 AU distance.

Whilst carrying out a detailed studying of Kuiper Belt Objects (KBOs) – the disk of rocky asteroids and comets surrounding the Sun from a distance of around 30 AU to about 50-60 AU, Volk and Malhotra discovered a consistent anomaly. Whilst most KBOs surround the sun with orbital inclinations that average out to what planetary scientists call the “invariable plane of the solar system”, they discovered that the more distance KBOs – those around 50 AU or over from the Sun are tilted away from the invariable plane by about eight degrees.

The pair surveyed around 600 of the 2,000 observed KBOs, and found all of those on the outer reaches of the Kuiper Belt to be inclined from the invariable plane by roughly the same amount and in numbers that tend to preclude a statistical fluke. In modelling possible causes for this, they discovered that an object with a mass of Mars, orbiting about 50-60 AU would cause just such a disruption, as would a Earth-sized body slightly further away.

However, Volk and Malhotra carefully avoid any suggestion there is a Mars- or Earth-sized body is awaiting discovery, noting that the disruption might also be the result of several large (but not planet-sized) masses lying within the outer fringes of the Kuiper belt. Even so, a single body would seem more likely, and given it is effectively sitting within the galactic plane – an area so densely packed with stars that solar system surveys tend to avoid it – could explain why it has been able to remain undetected.

An artist’s rendering of the LSST atop Cerro Pachón mountain, Chile. When LSST starts taking images of the entire visible southern sky in 2022, it will produce the widest, deepest and fastest views of the night sky ever observed. Over a 10-year time frame, LSST will image several tens of billions of objects and create movies of the sky with unprecedented detail – and might reveal whatever is causing the odd perturbations among the KBOs studied by Volk and Malhotra. Credit: Large Synoptic Survey Telescope Project Office

But it might not remain hidden for much longer. 2020 should see the Large Synoptic Survey Telescope (LSST) come on-line. This 8.4 metre (27.6 ft) primary mirror telescope is due to commence a 10-year sky survey in 2022. Among other things, it is expected to increase the number of KBOs so far observed from 2000 – to over 40,000 as it carries out real-time surveys of the sky, night after night. In doing so, it could well find any planet-sized body lurking near them.

Continue reading “Space Sunday: other worlds, near and far”

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Space Sunday: Jupiter, exoplanets, Opportunity, and Wow! again

The planets – actual size. Jupiter is the biggest – and most likely the oldest – of our solar system’s family of gas and solid body planets. Credit: NASA

Jupiter is the most massive planet of the solar system and its presence had an immense effect on the dynamics of the solar accretion disk (the disk of dust and stellar material which surrounded and formed the Sun). Knowing the age of Jupiter is key for understanding how the solar system evolved toward its present-day architecture. Although models predict that Jupiter formed relatively early in the solar system’s history, until now, its formation has never been dated. Now, an international study suggests it was the very first planet to form.

The team, comprising scientists from the US Lawrence Livermore National Laboratory and Germany’s Institut für Planetologie at the University of Münster, believe that Jupiter’s core started forming within the first million years of the solar system’s existence. By looking at tungsten and molybdenum isotopes on iron meteorites, the team found that meteorites are made up from two genetically distinct nebular reservoirs that coexisted but remained separated between 1 million and 3-4 million years after the solar system formed.

“The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the accretion disk, preventing the exchange of material between the two reservoirs,” said Thomas Kruijer, lead author of team’s paper, published in the June 12th Proceedings of the National Academy of Sciences.

“We do not have any samples from Jupiter (in contrast to other bodies like the Earth, Mars, the moon and asteroids),” he continued, when discussing the paper. “In our study, we use isotope signatures of meteorites (which are derived from asteroids) to infer Jupiter’s age. Jupiter is the oldest planet of the solar system, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.”

Even now, Jupiter sucks up material falling towards the Sun from further out in the solar system. This August 2009 image shows the result of an object striking the upper reaches of Jupiter’s southern hemisphere (south is at the top in the photo). The object was most likely a comet or asteroid a few hundred metres across. Credit: NASA

The team showed through isotope analyses of meteorites that Jupiter’s solid core formed within only about 1 million years after the start of the solar system history, rapidly growing to a mass of around 20 times that of Earth, then expanding more gradually to around 50 Earth masses over the next 2-3 million years. This rapid formation meant Jupiter acted as a barrier against inward transport of material from the outer reservoir of nebula material to the inner one, potentially explaining why our solar system lacks any super-Earths (a solid planet with a mass and size greater than Earth’s) orbiting the sun – Jupiter effectively vacuumed up the material.

The common belief among planetary scientists has leaned towards the gas giants of the outer solar system having formed relatively early in the solar system’s history, before the complete dissipation of the solar nebula—the gaseous circumstellar disk surrounding the young Sun – which occurred around 10 million years after the solar system formed. These finding fully support that belief, but has been able to far more precisely pin-down Jupiter’s birth date.

“Our measurements show that the growth of Jupiter can be dated using the distinct genetic heritage and formation times of meteorites,” Kruijer said.

Chinese Resupply Vehicle Competes 2nd Lab Refuelling

China’s automated Tianzhou-1 re-supply vehicle has carried out a successful second rendezvous with the currently uncrewed  Tiangong-2 space laboratory, and completed out a further refuelling operation of the orbital facility.

An artist’s impression of Tianzhou-1 (left) docked with the slightly larger Tiangong-2 orbital laboratory. Credit: CMSE

Launched in April 2017, Tianzhou-1 (“Heavenly Ship 1”) is the first of a series of resupply vehicles based on China’s first orbital module, Tiangong-1, designed to deliver up to 6.5 tonnes of equipment, supplies and fuel to orbital facilities – most notably China’s space station, construction of which is due to commence in 2018.

The 10.6m (34ft) long, 13 tonne Tianzhou-1 being prepared for installation into its launch shroud, April 2017. Image: CCTV

Tianzhou-1 is currently on an extended mission with the Tiangong-2 (“Heavenly Palace 2”) orbital facility, during which automated dockings at each of the laboratory’s two airlock systems are being practised, as is the transfer of fuel to the laboratory. The latter is a complicated, 29-step process, but one vital to the success of an orbital facility, where fuel is used in very small motor systems to help it maintain the correct orientation whilst in orbit and – potentially – help periodically boost the facility orbit to counter the microscopic (but cumulative) effect of atmospheric drag encountered whilst orbiting the Earth.

However, as such “boosts” to a space station’s orbit are more normally provided by an attached vehicle (the space shuttle used to do it for the International Space Station, for example, and the role has been taken over by the resupply craft which periodically visit the ISS). To this end, part of the Tianzhou-1 mission has also been to practice manoeuvring both the vehicle and  Tiangong-2 when the two have been docked. In addition, Tianzhou-1 has been carrying out its own free flight mission when not docked with the laboratory.

Like the European Automated Transfer Vehicle (ATV), Japanese H-II Transfer Vehicle (HTV) and American Cygnus resupply craft used in support of ISS operations, Tianzhou-1 is not designed to return to Earth. Instead, the vehicle will be allowed to burn-up as it re-enters the denser part of the Earth’s atmosphere at the end of its mission.

Following the Tianzhou-1 mission, a further crew of Chinese tiakonauts is expected to visit Tiangong-2 laboratory.

Kepler’s Latest Findings

NASA will announce the latest crop of planet discoveries from the Kepler Space Telescope on Monday, June 19th.

An artistic concept demonstrating gravitational microlensing. As an exoplanet passes in front of a more distant star, its gravity causes the trajectory of the starlight to bend, and in some cases results in a brief brightening of the background star as seen by a telescope, enabling scientists to search for exoplanets that are too distant and dark to be detected any other way (Credit: NASA / JPL / T. Pyle)

Kepler has been hunting for extrasolar planets since its launch in 2009, although the programme was almost cut short in 2013, following the failure of two of the reaction wheels (essentially gyroscope systems) used to stabilise the platform and allow it to gather data.

However, in November 2013, a new mission for the platform, dubbed “Second Light” and more generally referred to as the K2 mission,  was proposed and, after a successful period of test in early 2014, officially got under way on May 26th, 2014.

Most recently, Kepler has been using gravitational microlensing in an attempt to locate planets  orbiting stars so far away, the dimming of the star’s light by a transiting planet cannot easily be detected.

Kepler was the first mission capable of seeing planets the size of Earth around other stars in the “habitable zone” — the region at a distance from a star where liquid water could exist without freezing or boiling away immediately.

Thus far Kepler has found 4,496 exoplanet candidates. Some 2,335 have been confirmed and 21 are Earth-size planets in the habitable zone. Further, 520 of these exoplanet candidates have been found during the K2 mission, with 148 confirmed as having planets.

Continue reading “Space Sunday: Jupiter, exoplanets, Opportunity, and Wow! again”

Space Sunday: more Einstein, plus space planes and Wow!

This illustration reveals how the gravity of a white dwarf star warps space and bends the light of a distant star behind it. Credit: NASA, ESA, and A. Feild (STScI)

In his general theory of relativity, Albert Einstein predicted that whenever light from a distant star passes by a closer object, gravity acts as a kind of magnifying lens, brightening and bending the distant starlight in an effect known as “gravitational microlensing”.  While such microlensing has been observed using the Sun, it has never been used against an individual star (although it has been used binary pairs of stars) – until now.

During a two-year period between October 2013 and October 2015, astronomers used the Hubble Space Telescope (HST) did just that, allowing them to measure the mass of a star in the process.

The star in question is a white dwarf called Stein 2051 B, roughly 18 light years from Earth and part of a binary system, paired with a red dwarf. Essentially, the team of astronomers used Hubble to observe the effect the white dwarf had on the light being received from a star 5,000 light years away. By measuring the amount of apparent light deflection, the team were not only able to further confirm Einstein’s theory of relativity – they were able to measure the mass of the white dwarf itself, even though the deflection was tiny – only 2 milliarcseconds from its actual position.

“This microlensing method is a very independent and direct way to determine the mass of a star,” Kailash Sahu, the lead researcher on the project, explained following the publication of his team’s findings on June 7th, 2017. “It’s like placing the star on a scale: the deflection is analogous to the movement of the needle on the scale.”

On top of this, the observations confirmed the theory that a white dwarf star’s size is determined by its mass, first postulated in 1935 by Subrahmanyan Chandrasekhar, the Indian-American astronomer. Thus, a single set of observations have further confirmed Einstein’s theory of space-time to be correct (and sits alongside the detection of gravitational waves – see my last Space Sunday update – and observations of rapidly spinning pulsars in doing so), and confirmed the defining limits for a white dwarf star and allowed astronomers effectively measure the mass of a star.

Space Plane News

The United States Air Force has confirmed that the next mission for its X37B automated space plane will utilise a SpaceX Falcon 9 launch vehicle to boost it into orbit in August 2017.  This will be the fifth launch of the X-37B, which is also known as the Orbital Test Vehicle, and the first time a United Launch Alliance Atlas V booster hasn’t been used. It also marks the highest-profile US national security launch SpaceX will have signed-up for.

There are actually two of the uncrewed X-37B vehicles operated by the USAF which have been flown on alternate missions. The second of these two craft returned to Earth in May 2017 after spending an astonishing 718 days in orbit, carrying a mixed classified and non-classified cargo. The August mission will likely use the first of the two vehicles in its third mission, and will feature the Air Force Research Laboratory (AFRL) Advanced Structurally Embedded Thermal Spreader (ASETS-11) to test experimental electronics and oscillating heat pipes in the long duration space environment.

The USAF’s X-37B Orbital Test Vehicle (OTV) on the runway at Kennedy Space Centre at the end of the programme’s fourth mission, May 7th, 2017. The uncrewed vehicle is being “safed” by a Boeing team in protective suits to guard against harmful fumes and gases given off by the vehicle. Credit: USAF

At the same time as the USAF announcement about the X-37B, the South China Morning Post reported China’s own space plane programme is making “significant progress”.

China has been investigating the potential of operating some form of space plane since the late 1980s. Those plans ultimately didn’t go anywhere, and rumours of a new Chinese space plane, capable of flying astronauts and / or cargo to low Earth orbit started circulating in 2016, thanks to a news broadcast on Chinese state television service CCTV. However, as the report used imagery clearly taken from the UK’s Skylon programme, there was some doubt as to the veracity of the report.

 

In “announcing” the new space plane in 2016, China State television used images of the UK’s Skylon programme. Credit: CCTV

Like Skylon, the new Chinese vehicle, which the South China Morning Post refers to as athe Casic (the initials of the China Aerospace Science and Industry Corporation, said to be building the vehicle), will be able to take-off horizontally and use a hybrid propulsion system capable of flying it through the atmosphere and into space, carrying a crew and / or cargo to low Earth orbit. At the end of a mission, the vehicle will return to Earth and land on a conventional runway, where it can be re-serviced pretty much like a conventional military aircraft.

The South China Morning Post indicates that the new vehicle has “finished almost all ground experiments and overcome key technical hurdles such as engine design and construction”. However, no dates on when the vehicle might be rolled-out or start flight tests have been given. Nor have any specifics or official images of the vehicle been released. All that has been said is the vehicle will have an “aerodynamic shape” for atmospheric flight, and be larger than Virgin Galactic’s SpaceShipTwo, the VSS Unity.

Continue reading “Space Sunday: more Einstein, plus space planes and Wow!”

Enter the Snapdragon: Qualcomm and “XR”

The ODG R9 AR headset. Credit: Osterhout Design Group

It’s no secret that when it comes to augmented reality (AR) and virtual reality (VR), I’m swayed more towards AR and “mixed reality” (MR) as potentially being the “thing” of the future. Not, as I’ve often said, that I don’t believe in VR – it will in time grow to fill various niches and requirements. Rather, I just feel that AR / MR have a much wider field of application when it comes to impacting our daily lives.

I mention this because earlier in June I read an interesting piece by Dean Takahashi, examining Qualcomm’s emerging role in what they like to call “XR” – or “eXtended Reality”, which they define as a fusion of VR, AR and MR.

Qualcomm spells out the hurdles to ‘extended reality’ glasses offers a transcript  from a chat Dean had with Tim Leland, Qualcomm’s vice president of product management, on the company’s goal and the challenges they see in bringing headset-style devices to the market.

Qualcomm, of course, is the company behind the veritable Snapdragon family of processors. In 2016, they announced their intention to make the Snapdragon 835 chipset the heart of a new range of self-contained VR and AR devices. To that end, they are about to start shipping the Snapdragon 835 VR HMD to OEMs wishing to produce Android-powered VR headsets using the chipset and Google Daydream.

More particularly – from my perspective – Qualcomm has already partnered with Osterhout Design Group (ODG), to develop a range of Snapdragon-powered AR headsets. I first became aware of the first of these units, the R7, in mid-2016. Intended to be a heads-up AR system for enterprise solutions (selling at US $2,750), it has gained a degree of traction in a number of fields – hazardous environments (oil exploration and production, chemical production and pharmaceuticals, healthcare and surgery), and has been involved in tests helping the visually impaired.

In 2017, ODG are due to release two more units – the “prosumer” R8 (around US $1,500) and the “consumer R9 (at “sub-$1,000”). Again, these are Snapdragon 835 based, and will be fully self-contained units with Android and their operating system.

It is the self-contained aspect of such headsets which Qualcomm sees as being one of the keys to the future success of “XR”.

“Any type of cable is just a non-starter,” Leyland notes. “Fans will not exist. We think there might be a niche market for glasses that maybe stream to a PC, but that’s a small part of it. The big part is everything self-contained in a mobile device. All the visual processing systems are very close to the inertial sampling systems, so everything is very fast.”

Qualcomm see “XR” systems potentially becoming a mainstay of our daily lives, fusing VR and AR into a single headset unit which can meet a variety of needs at any given time, and which can also be used as the basis for specific use-cases.

A conceptual “first responder” XR headset for fire fighters. Credit: Qualcomm

In this Qualcomm see XR units being both general purpose and specific to market sectors. The company is already looking at a concept for a “first responder” headset for fire fighters. Containing night vision capabilities and thermal imaging sensors, the headset could allow fire fighters overlay their field-of-view with floor plans of the building they are in, helping them find their way through the smoke, while the thermal sensors warn of potential hotspots and possible behind-the-door risks of backdraft – and could even guide them to people trapped in a burning location.

A simplified rendering of the kind of information the “first responder” headset might provide. Credit: Qualcomm

For more general use, Qualcomm are looking at headsets which integrate much of what they’ve developed with the likes of ODG – multiple cameras, integral motion tracking, the ability to track eye and hand movements, etc., but in a very lightweight, unobtrusive form-factor with a low price point which makes them an attractive proposition.

Not that this is going to happen overnight. A refreshing aspect of Qualcomm’s view is that they are looking at a development / adoption curve measured in at least a decade. As Leyland notes, the ability to have AR and VR heads headsets exists today, but there are hurdles to be overcome before they are as ubiquitous as the mobile phone for many of the tasks we perform today.

Some of these hurdles are being independently addressed – 5G, for example, is expected to be of huge benefit to those uses which require a lot of rendering and so are latency intolerant. Others are going to take time to progress and solve:  display requirements – the vergence and accommodation conflict, human field of view (190ox130o) etc; common illumination); motion and tracking for intuitive head, hand and eye movements; and power and thermal issues.

The technical hurdles “XR” needs to overcome. Credit: Qualcomm

Leyland doesn’t see any of these hurdles as being problematic – he just emphases that the time frame required to solve them is not going to be as compressed as some of the more bullish predictions about VR growth made in 2016 would have us believe. Instead, he points to 2020 as still being a year when numbers of shipped headset units of all types is still measured in the hundreds of millions, although he does see it growing from there.

IDC VR shipment numbers (in thousands), have been seen as a means to question the reality of the VR market

But will these systems ever reach the ubiquitousness of the smartphone? Right now, going on the shipments of VR headsets some are quick to pooh-pooh the entire mixed reality (or XR if Qualcomm prefer) ecosystem in favour of alternatives. On the surface, they would seem to be right – but on a longer-term look? I’m not so sure. Again, this is where the much-hyped smartphone analogy with VR is misleading – as Leyland points out in talking to Takahashi.

While it is true the first “genuine” smartphone as we know them today only appeared a decade ago, the fact remains that it was founded on some three decades of cellular phone development. right now, headset capabilities are roughly in the “1990s” phase of that overall curve – so there is a way to go. As such, while headsets that more closely resemble glasses / sunglasses may not necessarily become as all-pervasive as smartphones are today, there is little reason to doubt they could – if they have an intuitive ease of use – take over from handsets (and associated wearables) for a wide variety of tasks / uses.

Qualcomm isn’t alone in pursuing a convergent future of mobile VR / AR / MR capabilities. However, through Dean Takahashi’s article (and courtesy of Qualcomm’s Augmented World Expo presentation, it is good to see how level-headed is the approach being taken be tech companies to bot understand the technology , its potential and to look beyond the buzz phrases like “killer app” or order to make “XR” work.