Category: Space Sunday

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: of Venus, Cosmic Girl and Cygnus

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

It is not often that I get to report on a space event that is happening right as I’m wiring about it; but that is precisely what happened as I wrote this edition of Space Sunday.

As I was typing, high above Venus, a little cube-like space craft measuring just over a metre on a side and supported by two stubby solar panel “wings”, had been making a final desperate attempt to enter orbit around the planet.

Akatsuki (“Dawn”), is a Japanese space probe also known by the names Venus Climate Orbiter (VCO) and Planet-C. Its mission is to study the dense, intense atmosphere of Venus and gain greater insight into how it formed, whether it has active weather phenomena such as lightning, and whether Venus itself may still be volcanically active. It is also a vehicle which has taken “the long way around” in order to reach its target.

Originally launched on May 20th, 2010 Akatsuki should have entered orbit around Venus on December 7th of that year. In order to do so, the vehicle had to carry out a 12-minute “burn” of its main engine to slow itself to the point where it would be caught by Venus’ gravity and so swing into an elliptical orbit. However, while the engine did fire as expected, a fuel valve failed, preventing the burn from being completed as required, and Akatsuki failed to achieve the desired orbit, and instead was left strained in a heliocentric (Sun-centred orbit) which would bring the craft back into proximity with Venus five years later – on the evening (UK time) of the 6th / 7th December 2015.

Having managed to keep the little craft alive and functioning during the intervening years, this second encounter offer a final opportunity to get Akatsuki safely into orbit around Venus, where it might complete its primary mission. Final because the craft has already far exceeded its operational life span, and such an opportunity is unlikely to come again.

Emily Lakdawalla provided this diagram of the Akatsuki orbit insertion attempt
Emily Lakdawalla of The Planetary Society provided this diagram of the Akatsuki orbit insertion attempt

So it was that at around 23:51 UTC on Sunday, December 6th, Akatsuki fired one set of its reaction control system (RCS) thrusters for 20 minutes in an attempt to push itself into an extended orbit around Venus (VOI – for Venus Orbital Insertion – in the diagram above).  Entirely automated, the attempt could, if required, be followed by an additional motor firing if telemetry received on Earth indicated the first burn had failed.

At 00:24 UTC on December 7th, data received from the vehicle, having taken over 8 minutes to be transmitted to Earth and then be processed, indicated the initial motor firing had been successful, and that Akatsuki should have established itself in an extended elliptical orbit around Venus, between 300,000 to 400,000 km above the surface of the planet. This is somewhat greater than the original orbit for the craft, which would have varied between 300 to 80,000 km, but it still should be close enough for the probe to undertake most of its science mission, although it will be several hours before this is confirmed.

 Cosmic Girl Gets Ready to Launch

Virgin Galactic is probably best known for two things: Richard Branson and trying to develop a sub-orbital flight capability which will allow fare-paying tourists enjoy a few minutes of “weightlessness” at the edge of space, marketing itself as the “world’s first commercial space line”.

However, the company is also looking to enter the lucrative market of commercial satellite launches, using a vehicle they’ve christened LauncherOne. The vehicle is specifically intended to to provide a launch capability for “smallsats”, sub-500 kg satellites, an increasingly poplar market sector, but one where very often the main means of getting into orbit is by “hitch-hiking” aboard launchers carrying other payloads.

Virgin Galactic: entering the satellite launch market with the 2-stage LauncherOne
Virgin Galactic: entering the satellite launch market with the 2-stage LauncherOne

Unlike most boosters, LauncherOne is designed to be air-launched. That is, carried aloft by an aircraft to an altitude of some 10,770 metres (35,000 ft) before being released to allow its first and second stage motors carry its payload up to the required orbit.

The technique isn’t new – it is used most notably by the Pegasus launch system developed by Orbital ATK, and which first flew in 1990. However, the technique offers some significant advantages. The most obvious of these is that by lifting the booster a fair way out of the denser part of the Earth’s atmosphere, less fuel is required for the rocket to reach orbit, reducing its overall mass and cost. Air-launched missions also aren’t restricted to a launchpad; they can be undertaken from any airport where there are suitable facilities for handling the booster itself, thus maximising the potential launch profiles a customer might need. When all the benefits are put together, it means that Virgin Atlantic can offer tailor-made smallsat launch capabilities to clients for just US $10 million a shot.

White Knight Two flying to the Farnborough air Show in 2012 with a mock-up of the original LauncherOne mounted beneath it (Image: Virgin Galactic)
White Knight Two flying to the Farnborough air Show in 2012 with a mock-up of the original LauncherOne mounted beneath it (Image: Virgin Galactic)

Continue reading “Space Sunday: of Venus, Cosmic Girl and Cygnus” →

Space Sunday: of rockets, moons, carbon and telescopes

Posted on by Inara Pey
Moments before touchdown: the Blue Origin propulsion module, having lobbed a New Shephard capsule on a sub-orbital flight, powers its way to a historic landing so it can be refurbished and re-used
November 23rd, 2015: moments before touchdown: the Blue Origin propulsion module, having lobbed a New Shephard capsule on a sub-orbital flight, powers its way to a historic landing so it can be refurbished and re-used (image: Blue Origin)

Blue Origin, the private space company founded by Amazon billionaire Jeff Bezos has become the first company to successfully launch a rocket into space – and return all elements of the vehicle to Earth for re-use.

The flight, carried out in West Texas, took place on Monday, November 23rd. It comprised the company’s New Shephard capsule, being flown in an uncrewed mode, and a single stage, recoverable booster is powered by an engine also developed by the company.

Unlike SpaceX, Orbital Sciences, Boeing and Sierra Nevada Space corporation, all of whom are directly pursuing rocket and space vehicle designs capable of orbital flight, Blue Origin is taking a more incremental approach, with efforts focused on the sub-orbital market “space tourism” market. The company is looking to build a cost-effective launch system capable of lifting small groups of paying passengers into space on ballistic “hops” which allow them to experience around 4-5 minutes of zero gravity before returning them to Earth.

The November 23rd flight saw the uncrewed New Shephard vehicle hoisted aloft by the booster system which reached a speed of Mach 3.72, sufficient for it to impart enough velocity to the capsule so that it could, following separation, continue upwards to an altitude of 100.5 kilometres (329,839 feet), before starting its descent back to the ground and parachuting to a safe landing.

April 25th: A camera aboard the propulsion module captures the rear of the New Shephard capsule moments after separation in the first test flight intended to recover both capsule and launcher - although the latter was in fact lost on that flight
April 25th: A camera aboard the propulsion module captures the rear of the New Shephard capsule moments after separation in the first test flight intended to recover both capsule and launcher – although the latter was in fact lost on that flight (image: Blue Origin)

Following capsule separation, however, the booster rocket Also made a control descent back to Earth, rather than being discarded and lost. The design of the booster – which Blue Origin call the “propulsion module” to differentiate to from a “simple” rocket – means it is semi-capable of aerodynamic free-fall, and won’t simply topple over and start tumbling back to Earth. At 6.5 kilometres (4 miles) above the ground, a set of eight drag brakes are deployed to slow the vehicle, with fins along the outside of the module allowing it to be steered. At 1.5 kilometres (just under 1 mile) above the landing pad, the unit’s motor reignites, further slowing it to a safe landing speed and allowing it to precisely manoeuvre itself onto the landing pad.

Highlights of the actual test flight, mixed with computer-generated scenes of the New Shephard capsule carrying a group of tourists on their sub-orbital hop was released by Blue Origin on November 25th.

One of the first to congratulate Blue Origin on their flight was Elon Musk, the man behind SpaceX, which is also pursuing the goal of building a reusable rocket system, but had yet to achieve a successful recovery of the first stage of their Falcon 9 booster. However, as Musk pointed out, there are significant differences and challenges involved in bringing a sub-orbital launch back to Earth and a booster  which has to reach far higher velocities in order to lob a payload into orbit, as SpaceX is already doing.

Not that Blue Origin doesn’t have orbital aspirations; both the “propulsion module” and New Shephard are designed to be integrated into a larger launch vehicle capable of placing the capsule into orbit.  The November 23rd flight itself marks the second attempt to launch and recover both New Shepard and the propulsion module; in April 2015, the first attempt succeeded in recovering the capsule, but a failure in the drag brake hydraulic system on the propulsion module resulted in its loss.

Martian Moon Starting Slow Breakup?

A Mercator map of Phobos showing the compex system of groves and potential lines of fracture across the little moon. Some of these, notably those located close to it, are thought to be the result of the impact which created Stickney crater (left of centre in the map); however most of them seem to be the first indications that Phobos is starting to slowly break-up
A Mercator map of Phobos showing the complex system of groves and potential lines of fracture across the little moon. Some of these, notably those located close to it, are thought to be the result of the impact which created Stickney crater (left of centre in the map); however most of them seem to be the first indications that Phobos is starting to slowly break-up (image: US Geological Survey)

Mars has two natural moons, Deimos and Phobos. Neither are particularly large; Deimos is only 15 × 12.2 × 11 km in size, and orbits Mars once every 30 hours;  Phobos measures just 27 × 22 × 18 km, and orbits the planet once every 7 hours and 39 minutes. Both exhibit interesting properties, in that Deimos is slowly moving away from Mars, and may even break from Mars’ influence in a few hundred million years.

Phobos, however is doing the reverse; it is gradually closing in on Mars at a rate of about 2 metres (6.6 ft) every 100 years. This means that over time, it is being exposed to greater and greater gravitational forces as it approaches its Roche limit.

Continue reading “Space Sunday: of rockets, moons, carbon and telescopes” →

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” →

Sunday Sunday: Mars, Pluto and WTF hits the atmosphere

Posted on by Inara Pey

CuriosityMars has been in the news a lot this last week, thanks to both the Curiosity rover and the MAVEN orbiter.

Curiosity’s science capabilities received a boost when a upgrade to the ChemCam test system on Earth increased the number of Earth-rock geochemical samples examined by the system tripled to some 350, vastly increasing the science team’s ability to improve their interpretation of data gathered by Curiosity’s ChemCam system – the laser and telescope / camera which vaporises small amounts of rocks on Mars and them images the plasma that’s given of for chemical and mineralogical analysis.

In particular, the upgrade has allowed the science team to re-examine data the rover gathered about a site with the most chemically diverse mineral veins so far examined on Mars. Called “Garden City”, the site sits above the “Pahrump Hills” area at the foot of “Mount Sharp”, which the rover examined in detail in late 2014 / early 2015. Of particular interest to scientists were a series of raised mineral veins criss-crossing the surface of the rocks in the area.

"Garden City", an outcrop about 1 metre (39 inches) high, examined by Curiosity in March 2015, and which exhibited mineral veins criss-crossing the surface of the rocks, and which exhibited different chemical signatures. New analysis capabilities on Earth have helped determine how the veins formed and what they may say about early conditions in Gale Crater.
“Garden City”, an outcrop about 1 metre (39 inches) high, examined by Curiosity in March 2015, and which exhibited mineral veins criss-crossing the surface of the rocks, and which exhibited different chemical signatures. New analysis capabilities on Earth have helped determine how the veins formed and what they may say about early conditions in Gale Crater

These new Earthside capabilities have allowed the science team to better analyse the minerals within the veins and make finer distinctions between them, revealing their mineral and chemical compositions vary one to another, and also appear to vary with age.

These findings suggest that, rather than being the result of a single extended wet period in Gale Crater during which water percolated down through fissures in the rock to leave the minerals behind, the veins are the result of several individual wet periods in Mars’ ancient past. These wet periods appear to have occurred somewhat later than the more extensive wet periods which gave rise to a successive series of lakes within Gale Crater, the sediments from which form the lowest slopes of “Mount Sharp”. As such, the veins give further hints to atmospheric changes going on at a time at which Mars’ climate was undergoing extraordinary changes and fluctuations in its ancient past.

Prominent mineral veins at the "Garden City" site examined by NASA's Curiosity Mars rover vary in thickness and brightness, as seen in this image from Curiosity's Mast Camera (Mastcam). The image covers and area roughly 2 feet (60 centimeters) across. Types of vein material evident in the area include: 1) thin, dark-toned fracture filling material; 2) thick, dark-toned vein material in large fractures; 3) light-toned vein material, which was deposited last.
Prominent mineral veins at the “Garden City” site examined by NASA’s Curiosity Mars rover vary in thickness and brightness, as seen in this image from Curiosity’s Mast Camera (MastCam).  The image covers and area roughly 60 cm (24 inches) across, and shows a mix of thin, dark-toned fracture filling material, likely deposited first, thick, dark-toned vein material in large fractures, and light-toned vein material, which was deposited last.

What Happened to Mars’ Atmosphere? The Answer is Blowin’ in the Wind

Atmospheric changes are also at the heart of the latest data to be analysed from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN). This data, part of the mission’s long terms studies of the planet’s atmosphere and environment greatly clarifies the key role played by the solar wind in the gradual loss of Mars’ once dense atmosphere and the transition of the planet’s climate from a warm and wet environment to the cold, arid planet we see today.

The solar wind is a stream of particles, mainly protons and electrons, flowing from the Sun’s atmosphere at a speed of about 1.6 million kilometres (1 million miles) per hour. The interaction of this solar wind generates an electric field around Mars, much like a turbine on Earth generates electricity. This electric field interacts with the upper reaches of Mars’ atmosphere, accelerating the ions there and shooting them into space.

An artist's impression of the solar wind shredding ions from Mars' atmosphere
An artist’s impression of the solar wind shredding ions from Mars’ atmosphere

MAVEN measurements indicate that gases are being stripped away in this manner from the Martian atmosphere at a rate of about 8.6 million tonnes per day. “Like the theft of a few coins from a cash register every day, the loss becomes significant over time,” said Bruce Jakosky, MAVEN principal investigator. “We’ve seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active.”

The impact of solar storms on the rate of loss from Mars’ atmosphere was directly observed by MAVEN at the start of 2015, when the planet was bracketed by a series of large-scale outpouring from the sun – the same solar activity which gave rise to the massive increase in auroral activity at that time (see my October 26th Space Sunday report).

“Solar-wind erosion is an important mechanism for atmospheric loss, and was important enough to account for significant change in the Martian climate,” Joe Grebowsky, MAVEN project scientist said of the data gathered by the mission. “MAVEN also is studying other loss processes – such as loss due to impact of ions or escape of hydrogen atoms – and these will only increase the importance of atmospheric escape.”

Continue reading “Sunday Sunday: Mars, Pluto and WTF hits the atmosphere” →