Tag: ISS

Space Sunday: of ice and salts, aurorae, and mountains

Posted on by Inara Pey
A true colour image returned by the Dawn space probe of one of the bright "spots" in Occator crater on Ceres, revealing what might be a cryo-volcano
A true colour image returned by the Dawn space probe of one of the bright “spots” in Occator crater on Ceres, revealing what might be a cryovolcano (credit:NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI)

The science team behind the joint NASA / ESA Dawn mission has released the most stunning high-resolution images yet seen of Ceres, one of the solar system’s three “protoplanets” located in the asteroid belt between the orbits of Mars and Jupiter.

The Dawn spacecraft has been mapping Ceres for also a year, operating at its lowest altitude above the tiny world since December 2015. During the course of the year, the images and data it has returned have, alongside information sent to us about Pluto and Charon by the New Horizons mission, caused planetary scientists to start seriously reconsidering all they thought they understood about minor planetary bodies in the solar system.

However, one thing everyone has been waiting for has been to see high-resolution images of Occator crater and the strange bright spots within it which have been the cause of so much interest and speculation, ever since they were first imaged by the Hubble Space Telescope.

A false-colour image showing the main peak in Occator crater with the small bright spots off to the right
A false-colour image showing the main peak in Occator crater with the small bright spots off to the right (credit:NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI)

While the vehicle may have commenced its most detailed mapping orbit of Ceres in December, due to the complexities of Dawn’s orbit around the tiny world, it was not until relatively recently that it was able to overfly the 92 km (57 mi) diameter Occator and capture images of what lay within it, and these images were released on March 22nd, as a part of a science briefing given at the 7th annual Lunar and Planetary Science Conference in Texas.

Taken from an altitude of just 385 kilometres (240 miles) above the crater, the images reveal a huge dome-like structure with a dimpled top forming the brightest of the “spots” in Occator. It looks for all the world like a volcano, prompting speculation that it might be what is called a “cryovolcano”. The theory here being that Ceres may contain significant quantities of volatiles (ices), which are gently heated by the dwarf planet’s interior, causing them to erupt through the surface layer, the deposits they leave behind slowly building up the volcano-like dome.

A false colour elliptical map of Ceres showing that Occator (just right of centre) is not the only bright spot on the tiny planetoid others, mostly associated with young (around 70-150 million years old) craters
A false colour elliptical map of Ceres showing that Occator (just right of centre) is not the only bright spot on the tiny planetoid others, mostly associated with young (around 70-150 million years old) craters (credit:NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI)

However, this is not he only theory on what might be happening. Spectral observations show that the light patches found in Occator and elsewhere are consistent with a magnesium sulphate called hexahydrite, which resembles Epsom salts here on Earth. Thus, an alternative theory is that impacts in places like Occator expose the salt-rich ices trapped in the crust to the vacuum of space. This causes the ice to sublimate (vaporise), leaving the salt behind.

Commenting on the two the two theories, Ralf Jaumann, planetary scientist and Dawn co-investigator at the German Aerospace Center (DLR) said, “Before Dawn began its intensive observations of Ceres last year, Occator Crater looked to be one large bright area. Now, with the latest close views, we can see complex features that provide new mysteries to investigate. The intricate geometry of the crater interior suggests geologic activity in the recent past, but we will need to complete detailed geologic mapping of the crater in order to test hypotheses for its formation.”

In the interim, NASA has released a new video summarising Dawn’s investigations of Ceres.

Cygnus Rendezvous with ISS

March 22nd saw the latest Orbital ATK Cygnus resupply vehicle lifted-off from Space Launch Complex 41 on Cape Canaveral Air Force Station, Florida in a spectacular night-time launch beneath a full Moon.

The automated vehicle, carrying 3.5 tonnes of supplies and equipment up to the International Space Station, made a flawless ascent into the Florida sky, the clear weather and moonlight offer some extraordinary opportunities for photographers, as shown in the image below, taken by Alex Polimeni for Spaceflight Now.

Long exposure photograph shows the trail of the Atlas V launch vehicle as it carries the Cygnus OA6 vehicle "Rick Husband" into orbit on March 22nd, 2016. In the foreground is the world famous Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Centre (credit: Alex Polimeni / Spaceflight Now)
Long exposure photograph shows the trail of the Atlas V launch vehicle as it carries the Cygnus OA6 vehicle “Rick Husband” into orbit on March 22nd, 2016. In the foreground is the world-famous Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Centre (credit: Alex Polimeni / Spaceflight Now)

Continue reading “Space Sunday: of ice and salts, aurorae, and mountains” →

Space Sunday: Dream Chasers Falcons, and spacewalks

Posted on by Inara Pey
The Dream chaser alongside NASA's space shuttle Atlantis
The Dream Chaser flight test article alongside NASA’s space shuttle Atlantis in 2010 (image: NASA / SNC)

NASA has announced a renewal to the current US private sector contracts to provide uncrewed resupply missions to the International Space Station (ISS) – and it came with something of a surprise.

SpaceX and Orbital ATK are the two US companies currently flying cargo resupply missions to the ISS, operating alongside Russian Progress vehicles and the Japanese H-II “Kounotori” Transfer Vehicle. Europe, which previously operated the largest cargo vehicle, the Automated Transfer Vehicle, ended ISS resupply missions in February 2015, and is now focused on supplying NASA with the Orion Service Module.

Both SpaceX, who can both launch and return up to 3.3 tonnes of cargo and trash to / from the space station using their Dragon cargo vehicle, and Orbital ATK,who can transport up to 3.5 tonnes of cargo / trash aboard their Cygnus vehicle (which burns-up on re-entering Earth’s atmosphere) have their resupply contracts renewed from 2019 through 2024, matching the extended lifetime of ISS operations. While this had been expected, the inclusion of a third vehicle, the Dream Chaser vehicle being developed by Sierra Nevada Corporation SNC surprised some.

Dream Chaser was unique among the commercial crew transportation proposals as it was based on a "lifting body" design , allowing to re-enter the Earth's atmosphere and glide to a landing on a conventional runway - aspects which still make it a very flexible vehicle
Dream Chaser was unique among the commercial crew transportation proposals as it was based on a “lifting body” design rather than a capsule system. Although launched atop a conventional rocket, the design allows it to re-enter the Earth’s atmosphere and glide to a landing on a conventional runway, making it an exceptionally versatile craft (image: SNC)

Dream Chaser was originally designed as part of NASA’s Commercial Crew Development (CCDev) programme aimed at having private sector companies provide the means of carrying crews back and forth between the space station and US soil. One of four proposals put to NASA under the programme, it was ruled out of the final selection in September 2014, with SpaceX and Boeing being chosen by NASA despite the fact that on paper, Dream Chaser offered potentially a better deal than Boeing’s CT-100 capsule.

While SNC lodged a complaint with the US Government Accountability Office (GAO) as a result of the decision, citing interference in the selection process by William Gerstenmaier, NASA’s top human exploration official, the GAO upheld the selection of SpaceX and Boeing for the crewed transport vehicles. However, NASA continued to work with SNC on various ideas for Dream Chaser, alongside of SNC looking at other options for the vehicle’s crew carrying capabilities to be put to use.

An artist's concept of the Dream Chaser Cargo docked with the ISS during a resupply flight
An artist’s concept of the Dream Chaser Cargo docked with the ISS during a resupply flight (image: SNC)

The new resupply contract will see SNC provide NASA with the uncrewed “Dream Chaser Cargo” variant of the vehicle, capable of flying up to 5 tonnes of cargo to / from orbit, As with the original crewed variant, the Dream Chaser Cargo will launch atop a rocket, but return to earth to make a conventional runway landing.

How many missions each of the three resupply vehicle types will fly is unknown; vehicles will be selected on the basis of flight / payload requirements and cost. The total cost of the contract, spilt between the three companies, is expected to be US $14 billion over the 5 years.

The Ice Volcanoes of Pluto

Scientists with NASA’s New Horizons mission have assembled the highest-resolution colour view of one of two potential cryovolcanoes spotted on the surface of Pluto, as the spacecraft hurtled by the little world in July 2015.

Informally called “Wright Mons”, the feature is about 150-160 kilometres (90-100 miles) across at its base, and about 4 km (2.5 miles) high. If it is in fact a volcano, it will be the largest such feature discovered in the outer solar system.

The feature has members of the New Horizons science team intrigued on two counts. The first is that there is a very sparse distribution of red material on its flanks. The second is that it apparently only has a single impact crater. This latter point suggests “Wright Mons” is relatively new surface feature on Pluto, while the former might suggest it is active, with ice ejected by eruptions covering the red material over time.

"Wright Mons" (the large dimple in the image on the right) and as seen in context with the rest of Pluto, may be one of two enormous cryovolcanoes on the tiny world (image: NASA/JPL / JHU/APL / SwRI)
“Wright Mons” (the large dimple in the image on the right) and as seen in context with the rest of Pluto, may be one of two enormous cryovolcanoes on the tiny world (image: NASA/JPL / JHU/APL / SwRI)

The images of “Wright Mons” were returned to Earth from New Horizons in November 2015. Since then, data from the Ralph instrument suite aboard the spacecraft has been used to add the colour details to the images, which have been composed into a new mosaic of the feature. If it and “Piccard Mons” are cryovolancoes, then they present further evidence that Pluto was (and might still be) geologically active.

Continue reading “Space Sunday: Dream Chasers Falcons, and spacewalks” →

Space Sunday: bringing a rocket home; uncovering Ceres

Posted on by Inara Pey
A second from touchdown: the Falcon 9 first stage booster, with landing legs deployed, about to make a successful landing at "Landing Zone 1", Cape Canaveral Air Force Station, having been launched from the space facility 10 minutes earlier as a part of a flight to deploy 11 Orbcomm telecommunications satellites
A second from touchdown: the Falcon 9 first stage booster, with landing legs deployed, about to make a successful landing at “Landing Zone 1”, Cape Canaveral Air Force Station, having been launched from the space facility 10 minutes earlier as a part of a flight to deploy 11 Orbcomm telecommunications satellites

On Monday, December 21st, the private space launch company SpaceX achieved a remarkable first in the annals of space flight: they successfully launched a payload carrying rocket into orbit, and then returned its first stage to a safe landing back on Earth, close to its original launch point.

The Falcon 9 rocket, in its first launch since June 2015 when a fuel tank failure lead to the vehicle’s destruction together with the Dragon resupply vehicle it was lifting to the International Space Station, was lifting a total of 11 communications satellites into orbit on behalf of Orbcomm.

The booster lifted-off from Florida’s Cape Canaveral Air Force Station at 20:29 EST on Monday, December 21st (01:29 UTC, Tuesday December 22nd).  At 2 minutes 27 seconds into the flight, having pushed the vehicle through the densest part of the atmosphere, the first stage engines shut down, and shortly afterwards, the first and second stages separated, allowing the latter’s Merlin engine to ignite.

As the second stage continued to accelerate up to deployment orbit, the first stage coasted upwards before using cold gas thrusters to effectively “flip” the booster around so it could use the first in a series of “boostback burns” of its main engines to slow itself down as well as pushing it back towards Cape Canaveral.

With this completed, the booster used the cold gas thrusters to again flip itself over so it would be descending engines first towards the ground, performing two further “boostback burns” to control its descent before making a final engine burn during the last few dozen metres of the descent and deploying its 4 landing legs and steering vanes for a successful touch down some 10 minutes after lift-off, which was captured by cameras on the ground and aboard an observing helicopter.

The SpaceX success came less than a month after Blue Origin, the private space company founded by Amazon billionaire Jeff Bezos, also landed the initial stage of their New Shephard launch system following a test launch. However, the latter is not intended to achieve orbital velocities at present, and so the booster stage – referred to as the “propulsion module” by Blue Origin – was not travelling nearly as fast as the Falcon 9 first stage, nor did it have to perform the complex “boostback” manoeuvres.

In the meantime, the second stage continued upwards, successfully deploying the Orbcomm satellites into LEO – low Earth orbit, at around 630 kilometres (just under 400 miles) altitude. With this part of the mission completed, the second stage booster also re-ignited its main engine, allowing it to achieve a geostationary transfer orbit and coast phase.

This was as important as the first stage landing because, while existing Falcon 9 rockets are capable of placing large payloads into geosynchronous equatorial orbit, some 36,000 km (22,000 miles) above the surface of the Earth, it has required the first stage of the rocket to do much more of the work, leaving it with insufficient fuel reserves to attempt a return to Earth and landing. The uprated second stage, tested as a part of this flight, alleviates the first stage of some of the booster phase work, allowing it to retain the fuel it needs to make a successful return to Earth.

The overall hope with the upgraded Falcon 9 and the new landing facilities at Cape Canaveral, is that they will allow SpaceX to lower launch costs to the benefit of customers, and allow them to make more efficient use of their boosters rather than just tossing them away into the Atlantic or Pacific after a single use.

However, even with this first successful landing, the company still has some significant hurdles to clear. One of these will be demonstrating it can refurbish used first stages at a fast enough pace to be able to maintain a launch cadence high enough to be attractive to commercial operators looking for launch opportunities, rather than risking them look to those companies able to offer a faster launch rate.

Nevertheless, SpaceX’s achievement is clear, and after the disappointments in trying to recover the Falcon 9 first stage at sea (initially seen as a “safer” option due to the negligible risk of civilian injuries if anything went wrong when compared to  returning a rocket to Earth near populated areas), deserves every congratulation.

Dawn over Ceres

Dawn mission patch (NASA / JPL)
Dawn mission patch (NASA / JPL)

Dawn, the NASA / ESA joint mission currently mapping Ceres, one of the solar system’s three “protoplanets” located in the asteroid belt between the orbits of Mars and Jupiter, reached its lowest planned orbital altitude in early December, ready to start the final phase of its mission.

The new orbit, just 385 km (230 miles) above Ceres mains the craft can image the surface at a resolution of 35 metres (120 feet) per pixel.

Of particular interest to the science team has been determining the mysterious bright patches seen within the crater Occator during Dawn’s approach to Ceres and during its higher mapping orbits. While perhaps the largest found, the bright spots in Occator are not alone – around 130 bright spots have been located, almost all of them within Ceres’ craters, and analysis now shows that the material  seems to be consistent with salts, such as sulfates, with silicate materials also very likely present.

A false-colour representation Occator Crater on Ceres reveals the short wavelength of the bright deposits in the crater, pointing to them being salts. Occator measures about 90 km (60 miles) across
A false-colour representation Occator Crater on Ceres reveals the short wavelength of the bright deposits in the crater, pointing to them being salts. Occator measures about 90 km (60 miles) across

Continue reading “Space Sunday: bringing a rocket home; uncovering Ceres” →

Space Update: silica mysteries, Brits in space and tracking Santa

Posted on by Inara Pey

new-horizonNew Horizons is still less than half way through transmitting the data gathered during its fly-past of the Pluto-Charon system in July 2015, but the wealth of information received thus far has already revealed much about Pluto and its “twin”.

Geological evidence has been found for widespread past and present glacial activity, including the formation of networks of eroded valleys, some of which are “hanging valleys,” much like those in Yellowstone National Park, Wyoming. A major part of this activity is occurring in and around “Sputnik Planum”, the left half of Pluto’s “heart”, a 1,000 km (620 mile) wide basin, which is seen as key to understanding much of the current geological activity on Pluto.

Images and data gathered for this region has given rise to new numerical models of thermal convection with “Sputnik Planum”, which is formed by a deep layer of solid nitrogen and other volatile ices. These not only explain the numerous polygonal ice features seen on Sputnik Planum’s surface, but suggest the layer is likely to be a few kilometres in depth.

Evaporation of this nitrogen, together with condensation on higher surrounding terrain is believed causing a glacial flow from the higher lands back down into the basin, where the ice already there is pushed, reshaping the landscape over time.

A ture colour image of Pluto's surface, captures just before the point of closest approach, and created by combining black-and-while images from from the LORRI camera with data gathered by the Ralph instrument suite. The picture show the highlands to one side of "Sputnik Planum with the pockmarked ices of the basin. A combination of evaporation and condensation between the two is giving rise to sustained glaciation on Pluto, showing it to be an active world
A true colour image of Pluto’s surface, captures just before the point of closest approach, and created by combining black-and-while images from from the LORRI camera with data gathered by the Ralph instrument suite. The picture show the highlands to one side of “Sputnik Planum” with the pockmarked ices of the basin. A combination of evaporation and condensation between the two is giving rise to sustained glaciation on Pluto, showing it to be an active world (image: NASA, JHU/APL SwRI)

More data and images have also been received regarding Pluto’s atmosphere, allowing scientists start to probe precisely what processes are at work in generating and renewing the atmosphere, the upper limits of which are subject to erosion by the solar wind, which strike Pluto at some 1.4 million kilometres per hour (900,000 mph).

As well as understanding the processes which are at work renewing the atmosphere, and thus preventing it from being completely blasted away by the solar wind, science teams are hoping to better further why the haze of Pluto’s atmosphere forms a complicated set of layers – some of which are the result of the formation and descent of tholins through the atmosphere – and why it varies spatially around the planet.

The Mars Silica Mystery

In July I covered some of the work going into investigating the mystery of silica on Mars. This is a mineral of particular interest to scientists because high levels of it within rocks could indicate conditions on Mars which may have been conducive to life, or which might preserve any ancient organic material which might be present. In addition.

As I reported back in July, scientists have been particularly interested in the fact that as Curiosity has ascended “Mount Sharp”, so have the amounts of silica present in rocks increased: in some rocks it accounts for nine-tenths of their composition. Trying to work out why this should be, and identifying the nature of some of the silica deposits has given rise to a new set of mysteries.

The first mystery is trying to understand how the silica was deposited – something which could be crucial in understanding how conducive the environment on “Mount Sharp” might have been for life. Water tends to contribute to silica being deposited in rocks in one of two ways. If it is acidic in nature, it tends to leach away other minerals, leaving the silica behind. If it is more neutral or alkaline in nature, then it tends to deposit silica as it filters through rooks.

This May 22, 2015, view from the Mast Camera (Mastcam) in NASA's Curiosity Mars rover shows the "Marias Pass" area where a lower and older geological unit of mudstone -- the pale zone in the center of the image -- lies in contact with an overlying geological unit of sandstone. This view from the Mast Camera (Mastcam) in NASA's Curiosity Mars rover shows the "Marias Pass" area where a lower and older geological unit of mudstone -- the pale zone in the center of the image -- lies in contact with an overlying geological unit of sandstone. Just before Curiosity reached Marias Pass, the rover's laser-firing Chemistry and Camera (ChemCam) instrument examined a rock found to be rich in silica, a mineral-forming chemical. This scene combines several images taken on May 22, 2015, during the 992nd Martian day, or sol, of Curiosity's work on Mars. The scene is presented with a color adjustment that approximates white balancing, to resemble how the rocks and sand would appear under daytime lighting conditions on Earth.
This mosaic of images captures by Curiosity’s Mastcam on May 22nd 2015 (Sol 992), shows the “Marias Pass” region where mudstone (the pale rock in the centre of the image) of the kind the rover had been studying, overlaid by a geological unit of sandstone. rocks in this area should very high concentrations of silica in them, much higher than previously encountered, which the rocks above the area show strong evidence of silica deposition as a result of water action. This image has been white balanced to show the rock under Earth equivalent natural lighting conditions (image: NASA / JPL)

If the water which once flowed down / through “Mount Sharp” was acidic in nature, it would likely mean that the wet environments found on the flanks of the mound were hostile to life having ever arisen there or may have removed any evidence for life having once been present. If evidence that the water was acidic in nature, then it would also possibly point to conditions on “Mount Sharp” may have been somewhat different to those found on the crater floor, where evidence of environments formed with more alkaline water and with all the right building blocks for life to have started, have already been discovered.

The second mystery with the silica is the kind of silica which has been discovered in at least one rock.  Tridymite is a polymorph of silica which on Earth is associated with high temperatures in igneous or metamorphic rocks and volcanic activity. Until Curiosity discovered significantly high concentrations of silica in the “Marias Pass area of “Mount Sharp” some seven months ago – something which led to a four month investigation of the area – tridymite had never been found on Mars.

The region just above "Marias Pass" contained an area referred to as the "Stimson Unit" which showed fracturing rich in silica when compared to the surrounding rocks, suggesting deposition of silica / leaching of other minerals as a result of water action
The region just above “Marias Pass” contained an area referred to as the “Stimson Unit” which showed fracturing rich in silica when compared to the surrounding rocks, suggesting deposition of silica / leaching of other minerals as a result of water action (images: NASA / JPL)

“Marias Pass” and the region directly above it, called the “Stimson Unit” show some of the strongest examples of silica deposition on “Mount Sharp”, and  it was in one of the first rocks, dubbed “Buckskin”, exhibiting evidence of silica deposits in which the tridymite was found.

The question now is: how did it get there? All the evidence for the formation of “Mount Sharp” points to it being sedimentary in nature, rather than volcanic. While Mars was very volcanic early on in its history, the presence of the tridymite on “Mount Sharp” might point to volcanic /  magmatic evolution on Mars continuing for longer than might have been thought, with the mineral being deposited on the slopes of the mound as a result of wind action. Or alternatively, it might point to something else occurring on Mars.

Continue reading “Space Update: silica mysteries, Brits in space and tracking Santa” →

Space Sunday: clouds, sand, meteors and launches

Posted on by Inara Pey
Artist's impression of Akatsuki in orbit around Venus
Artist’s impression of Akatsuki in orbit around Venus

In my last Space Sunday update, I was writing at the very time a final effort was being made to see a little Japanese space probe finally achieve an operational orbit around Venus, precisely five years to the date after the first attempt failed as a result of the craft’s primary motor malfunctioning.

At the time of writing that update, it appeared as if little Akatsuki (“Dawn”), designed to probe the Venusian climate and atmosphere had finally arrived in orbit about the planet, but as I noted, final confirmation would take a while.  In the end, it wasn’t until Wednesday, December 9th that the Japan Aerospace eXploration Agency (JAXA) did confirm Akatsuki, less than a metre on a side (excluding its solar panels) was secure in its orbit around Venus and would likely be able to complete its mission.

Following the failure of its main engine on December 7th 2010 during a critical braking manoeuvre, the probe had finished up in a heliocentric orbit, circling the sun and heading away from Venus. However, orbital mechanics being as they are, both the probe and Venus would occupy the same part of space once again in December 2015, presenting final opportunity to push the probe into orbit using its RCS manoeuvring thrusters. This is precisely what happened on the night of December 6th / 7th, 2015. While not designed for this purpose, a set of the probe’s RCS thrusters undertook a 20-minute burn just before midnight UTC on December 6th, and preliminary telemetry received on Earth some 30+ minutes later showed Akatsuki had achieved sufficient braking to enter a very elliptical orbit around Venus.

A simple orbital diagram released as a part of the low-key JAXA press release confirming Akatsuki had arrived in orbit around Venus
A simple orbital diagram released as a part of the low-key JAXA press release confirming Akatsuki had arrived in orbit around Venus (image: JAXA)

Data received since then show that the craft is in an eccentric orbit with an apoasis altitude (the point at which it is furthest from the surface of Venus) of around 440,000km, and a periapsis altitude (the point at which it is closest to the surface of Venus) of around 400km. This is a considerably broader orbit than the mission had originally intended back in 2010, giving the vehicle an orbital period of around 13.5 days, the orbit slightly inclined relative to Venus’ equator.

An ultra-violet image of Venus, returned by Akatsuki shortly after achieving its initial orbit around the planet, and having passed through periapis, already heading away from the planet
An ultra-violet image of Venus, returned by Akatsuki shortly after achieving its initial orbit around the planet, having passed periapsis during the braking manoeuvre, to head away from the planet (image: JAXA)

In order to maximise the science return from the vehicle – which is now operating well in excess of its designed operational life – JAXA plan to use the next few months to gradually ease Akatsuki in an orbit which reduces both the apoasis distance from Venus, and bring down the orbital period to about 9 days.

These manoeuvres will likely be completed by April 2016, allowing the full science mission to finally commence.  This is aimed at learning more about the atmosphere and weather on Venus as well as confirm the presence of active volcanoes and thunder, and also to try to understand exactly why  Earth and Venus developed so differently from each other, despite being seen as sister planets in some regards.

Even so, right from its arrival in its initial orbit, Akatsuki has been flexing its muscles, testing its imaging systems and returning a number of preliminary pictures of Venus to Earth, such as the ultra-violet image shown above right, captured just after the craft finally achieved orbit.

Curiosity reaches Sea of Sand

NASA’s Mars Science Laboratory rover Curiosity has reached the edge of the major “sea” of sand dunes located on the flank of “Mount Sharp”. Dubbed the ““Bagnold Dunes” after British military engineer Ralph Bagnold, who pioneered the study of sand dune formation and motion, doing much to further the understanding of mineral movements and transport by wind action. Such studies are seen as an essential part of understanding how big a role the Marian wind played in depositing concentrations of minerals often associated with water across the planet, and by extension, the behaviour and disposition of liquid water across Mars.

Sand is not a new phenomenon for rovers on Mars to encounter – Curiosity, Opportunity and Spirit have all had dealings with it in the past; in fact Spirit’s mission as a rover came to an end in 2009, after it effectively got stuck in a “sand trap”. However, the “Bagnold Dunes” are very different to the sandy environs previously encountered by rovers; it is a huge “genuine” dune field where the sand hills can reach the height of 2-storey buildings and cover areas equivalent to an American football field.

The rippled surface of the first Martian sand dune ever studied up close. Captured by Curiosity's Mastcam on November 27th, 2015 (Sol 1,176 on Mars), the view is looking up the curved slope of "High Dune", revealing a rippled surface of sand sculpted by the wind. The Bagnold dunes" are "active", in that they are migrating down the slope of "Mount Sharp" at the rate of around one metre (39 inches) a year. The dunes are active, migrating up to about one yard or meter a year.
The rippled surface of the first Martian sand dune ever studied up close. Captured by Curiosity’s Mastcam on November 27th, 2015 (Sol 1,176 on Mars), looking up the curved slope of “High Dune” as it rises above Curiosity. The “Bagnold Dunes” are “active”, in that they are migrating down the slope of “Mount Sharp” at the rate of around one metre (39 inches) a year  (image: NASA / JPL)

So far, Curiosity has only probed the edge of the dune field around a sand hill originally dubbed “Dune 1”, and now called “High Dune”, using both its camera to image the region and its wheels to test the surface material prior to moving deeper into the sands. Wheel slippage is a genuine concern for the rover when moving on loose surfaces, as it can both overtax the motors and put the rover at risk of toppling over. Given this, and while there are no plans to attempt any ascent up the side of a dune, the mission team are taking things cautiously.

Continue reading “Space Sunday: clouds, sand, meteors and launches” →

Space Sunday: the sand dunes of Mars and flying to the ISS

Posted on by Inara Pey

CuriosityThe Mars Science Laboratory rover, Curiosity, continues to climb the flank of “Mount Sharp” (formal name: Aeolis Mons), the giant mount of deposited material occupying the central region of Gale Crater around the original impact peak. For the last three weeks it has been making its way slowly towards the next point of scientific interest and a new challenge – a major field of sand dunes.

Dubbed the “Bagnold Dunes”, the field occupies a region on the north-west flank of “Mount Sharp”, and are referred to as an “active” field as they moving (“migrating” as the scientists prefer to call it) down the slops of the mound at a rate of about one metre per year as a result of both wind action and the fact they are on a slope.

Curiosity has covered about half the distance between its last area of major study and sample gathering and the first of the sand dunes, simply dubbed “Dune 1”. During the drive, the rover has been analysing the samples of rock obtained from its last two drilling excursions  and returning the data to Earth, as well as undertaking studies of the dune field itself in preparation for the upcoming excursion onto the sand-like surface.

While both Curiosity and, before it, the MER rovers Opportunity and Spirit have travelled over very small sand fields and sand ripples on Mars, those excursions have been nothing like the one on which Curiosity  is about to embark; the dunes in this field are huge. “Dune 1”, for example, roughly covers the area of an American football field and is equal in height to a 2-storey building.

"dune 1" in the "Bagnold Dunes", imaged here by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter (MRO) is roughly 300 metres across and as tall as a 2-storey building. The image is in false color, combining information recorded by HiRISE in red, blue-green and infrared frequencies of light.
“dune 1” in the “Bagnold Dunes”, imaged here by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO) is roughly 300 metres across and as tall as a 2-storey building. The image is in false colour, combining information recorded by HiRISE in red, blue-green and infra-red frequencies of light.

While the rover will not actually be climbing up the dune, it will be traversing the sand-like material from which it is formed and gathering samples using the robot arm scoop. This is liable to be a cautious operation, at least until the mission team are confident about traversing parts of the dune field – when Curiosity has encountered Martian sand in the past, it has not always found favour; wheel slippage and soft surfaces have forced a retreat from some sandy areas the rover has tried to cross.

Study of the dunes will help the science team better interpret the composition of sandstone layers made from dunes that turned into rock long ago, and also understand how wind action my be influencing mineral deposits and accumulation across Mars.

On Earth, the study of sand dune formation and motion, a field pioneered by British military engineer Ralph Bagnold – for whom the Martian dune field is named – did much to further the understanding of mineral movements and transport by wind action.  Understanding how this might occur on Mars is important in identifying how big a role the Marian wind played in depositing concentrations of minerals often associated with water across the planet, as opposed to those minerals accumulating in those areas as a direct consequence of water once having been present.

A mosaic of images taken on September 25th, 2015 (Sol 1,115) captures by the right lens of the rover's Mastcam system. .The view is toward south-south-west and reveals the "Bagnold Dunes" as a dark band across the middle of the image, blending with mesas beyond them
A mosaic of images taken on September 25th, 2015 (Sol 1,115) captures by the right lens of the rover’s Mastcam system. .The view is toward south-south-west and reveals the “Bagnold Dunes” as a dark band across the middle of the image, blending with mesas beyond them

Next NASA Rover to Have its Own Drone?

In January I wrote about ongoing work to develop a helicopter “drone” which could operate in concert with future robot missions to Mars. Now the outgoing director of NASA’s Jet Propulsion Laboratory has indicated the centre would like to see such a vehicle officially included as a part of the Mars 2020 rover package.

Weighing just one kilogramme (2.22 pounds) and with a rotor blade diameter of just over a metre (3.6 feet), the drone would be able to carry a small instrument payload roughly the size of a box of tissues, which would notably include an imaging system. Designed to operate as an advanced “scout”, the drone would make short daily “hops” ahead of, and around the “parent” rover to help identify safe routes through difficult terrain and gather data on possible points of scientific interest which might otherwise be missed and so on.

Since January, JPL has been continuing to refine and improve the concept, and retiring JPL Director Charles Elachi has confirmed that by March 2016, they will have a proof-of-concept design ready to undergo extensive testing in a Mars simulation chamber designed to reproduce the broad atmospheric environment in which such a craft will have to fly. The centre hopes that the trials will help convince NASA management – and Congress – that such a drone would be of significant benefit to the Mars 2020 mission, and pave the way for developing drones which might be used in support of future human missions on the surface of Mars.

Continue reading “Space Sunday: the sand dunes of Mars and flying to the ISS” →