Space Sunday: of rockets, rovers and impacts

Blue Origin's New Shephard lifts-off on Saturday, April 2nd on a successful sub-orbital test flight which saw both capsule and propulsion module successfully recovered
Blue Origin’s New Shephard lifts-off on Saturday, April 2nd on a successful sub-orbital test flight which saw both capsule and propulsion module successfully recovered

Blue Origin, established by  Amazon founder Jeff Bezos, scored a three-for-three with launches and landings of their sub-orbital New Shephard launch vehicle.

Intended to offer passengers the opportunity to experience the microgravity of space, New Shephard is a two stage vehicle comprising the capsule unit which will eventually carry  6 people to the each of space, and a rocket stage simply called the “propulsion module”. Both are designed to be fully re-usable in order to reduce the overall cost of launch operations.

The Blue Origin propulsion module just a couple of seconds from touch down on April 2nd, 2016 (image: Blue Origins)
The Blue Origin propulsion module just a couple of seconds from touch down on April 2nd, 2016 (image: Blue Origins)

Having first flown on November 23rd, 2015, when the capsule unit reached an altitude of 100.5 km (63 mi) before parachuting back to a soft landing and the propulsion module made a powered descent and landing, the April 2nd, 2016, marked the third successful flight for both capsule and propulsion module, the latter now having been used for all three successful flights in November 2015, January 2016 and April 2016.

During the flight, the capsule – which was carrying a small science payload – reached a maximum altitude of 103.4 km (64.4 mi) before making a return to Earth under its parachutes, while the propulsion module steered its way back to the launch site to make a powered landing.

Nor was this a run-of-the-mill return for the propulsion module, as a the ascent / descent engine was re-lit at a much higher altitude that is expected during operational flights, at around 1,107 metres (3,600 ft), in a manoeuvre designed to further test the engine’s reliability and the wear and tear it might suffer during a flight. Understanding both of these factors will help Blue Origin better identify the overall costs involved in refurbishing rocket and engines between flights.

The New Shephard capsule, whilst primarily intended to fly people on sub-orbital flights, can also be used for science research, as demonstrated in this flight, which saw the capsule carry the Box of Rocks experiment from the Southwest Research Institute, designed to explore how rocky debris settles in microgravity, and the University of Central Florida’s Collisions into Dust experiment, which aims to better understand how large bodies interacted with dust in the early Solar System.

The New Shephard capsule being recovered following its parachute landing (image: Blue Origin)
The New Shephard capsule being recovered following its parachute landing (image: Blue Origin)

While Blue Origin appear to be slightly ahead of SpaceX in terms of launching and recovering their rockets, it’s important to remember that the current New Shephard vehicle and the SpaceX Falcon 1.1 are very different beasts. Not only is the latter some 3 times bigger than New Shepard, the first stage of the vehicle flies much higher and faster than the Blue Origin vehicle, both of which make returning the first stage of the booster to a landing site to make a safe touchdown far more of a technical challenge.

That said, the sub-orbital capabilities of New Shephard are only one phase of Blue Origin’s plans. With the vehicle expected to commence crewed test flights in 2017 and offer sub-orbital tourist flights from 2018, the company plan to gradually uprate the vehicle to a point were it will also be able to undertake orbital launches and still be recovered.

Walking with Rovers

NASA is continuing to ramp public interest in Mars, with a new public outreach programme set to begin in summer 2016.

Destination: Mars builds on the ongoing cooperative work between the space agency and Microsoft in developing applications and opportunities for the Miscrosoft HoloLens system. As I’ve previously reported, NASA is already using the HoloLen aboard the International Space Station, and have also developed a means for members of the Curiosity science team put themselves “on” Mars using the HoloLens and data / images returned by the rover.

It is in the latter capacity that Destination: Mars is designed to work, offering the public, using the mixed reality capabilities of the HoloLens to “visit” Mars.

Apollo 11 Lunar Module Pilot and second man on the Moon, Edwin "Buzz" Aldrin, acts as a virtual host for Destination: Mars
Apollo 11 Lunar Module Pilot and second man on the Moon, Edwin “Buzz” Aldrin, acts as a virtual host for Destination: Mars

Continue reading “Space Sunday: of rockets, rovers and impacts”

Space Sunday: From Pluto’s ocean to Mercury’s darkness

Water ice had been identified by the RALPH instrument suite on New Horizons, now it seems Pluto may have a liquid ocean beneath its surface
Water ice had been identified by the Ralph instrument suite on New Horizons (shown on blue), now it seems Pluto may have a liquid ocean beneath its surface (Credit: NASA/JHUAPL/SwRI)

It may be so far away that the Sun appears to be a particularly bright star it is sky, but it now seems that Pluto has a liquid ocean just beneath its icy surface, just as might have once been the case with its companion, Charon, billions of years ago.

Since passing through the Pluto-Charon system in July 2015, NASA’s New Horizons space craft has been returning the data it gathered at a steady rate, focusing initially on the high-resolution images collected during the probes high-speed run by the two tiny worlds (both smaller than the Moon). These images have revealed Pluto and Charon to be remarkably complex little worlds, with glacial flows, rotated ice blocks, volcano-like mounds and other features rivalling the geology found on much larger, warmer planets like Mars.

“What we see really has exceeded all of our collective expectations and imagination,” said William McKinnon, a planetary scientist at Washington University, Missouri, and one of those working on the project. “We think on the insides of these bodies were very cold ammonia rich oceans,” said McKinnon, noting that ammonia is a “fantastic antifreeze” that can lower the freezing point of water by 100 C.

A close-up of the canyons on Charon, Pluto's big moon, taken by New Horizons during its close approach to the Pluto system last July. Multiple views taken by New Horizons as it passed by Charon allow stereo measurements of topography, shown in the color-coded version of the image. The scale bar indicates relative elevation. Credits: NASA/JHUAPL/SwRI
A close-up of the canyons on Charon, taken by New Horizons during its close approach to the Pluto system last July, reveal how the surface was “cracked open” as the subsurface ocean froze-out and expanded (credit: NASA/JPL / John Hopkins University Applied Physics Laboratory  / SwRI)

Data from New Horizons indicate that Charon’s ocean probably froze solid around 2 billion years ago, expanding as it did so, cracking open the outer shell of the world. This freezing-out was likely due to Charon being too small to remain geologically active, its internal processes quickly slowing down as it cooled. Pluto, however, being larger, shows every sign of still being active and with a warm interior, so its subsurface ocean probably still exists, marking it as another in a handful of the solar system’s smaller bodies which are home to sub-surface oceans.

“We now have half a dozen worlds, like Enceladus (a moon orbiting Saturn), Europa and Ganymede (moons of Jupiter), and now Pluto, that seem to have oceans in their interiors,” New Horizons’ lead scientist Alan Stern said when discussing the potential and significance of Pluto’s ocean.

Fumeroles (hydrothermal vents) support exotic life on Earth's seabed
Fumeroles (hydrothermal vents) support exotic life on Earth’s seabed

We know that life is remarkably tenacious and is extraordinary for surviving in unlikely places. All that is required is heat, a source of energy and water. On Earth, for example, volcanic fumeroles on the deep ocean floor can become havens for exotic life in places where sunlight never reaches.

This has led to speculation that places like Europa, which generates a lot of internal heat due to gravitational flexing thanks to the presence of Jupiter and the other large Galilean satellites, may well have similar, mineral-rich fumeroles on its ocean floor which may be havens for life exotic, basic forms of life. Could Pluto have the same?

“All we can say is that we think that Pluto has an ocean and we think that this ocean has survived to the present day. It’s the kind of ocean that is deep inside the interior of Pluto, in total darkness,” McKinnon stated.

“But, it would lie between a floating water ice shell and the rocky interior, so it would be in contact with rock. There would be a modest amount of heat leaking out. You certainly couldn’t rule it out, but anything about life on Pluto is simply speculation.”

Whether or not any basic life has managed to develop deep under Pluto’s icy crust is something we may never discover. However, that a liquid ocean does appear to exist beneath the planet’s icy shell is nevertheless intriguing. That water is present on Pluto has already been confirmed by the Ralph instrument suite aboard New Horizons. However, further evidence of its existence was revealed in February with the publication of images of “floating” hills of water ice on the nitrogen ice “sea” of Sputnik Planum”.

These hills are thought to be fragments which have broken away from the uplands surrounding “Sputnik Planum”. They exist in chains multiple kilometres in length or are grouped together, standing in stark contrast to the relatively flat expanse of the icy plain on which they sit.

Because water ice is less dense than nitrogen-dominated ice, scientists believe these water ice hills are like icebergs in Earth’s Arctic Ocean. In particular, the “chains” of hills have formed along the flow paths of the glaciers, while in the more “cellular” terrain of central “Sputnik Planum”, they become subject to the convective motions of the nitrogen ice, and are pushed to the edges of the cells, where the hills form clusters or groups. One of the largest of these, located towards the north of “Sputnik Planum” and measuring some 60km x 35km (37 mi x 22 mi) has been dubbed “Challenger Colles” in memory of the crew of the lost space shuttle Challenger.

The floating water ice hills of Pluto, slowly drifting over the nitrogen ice of "Sputnik Planum"
The floating water ice hills of Pluto, slowly drifting over the nitrogen ice of “Sputnik Planum” (Credit: NASA/JPL / John Hopkins University Applied Physics Laboratory  / SwRI)

Continue reading “Space Sunday: From Pluto’s ocean to Mercury’s darkness”

Space Sunday: the Martian tilt and Plutonian clouds

Tethys, Enceladus and Mimas seen above and blow Saturn's rings in a stunning image captured by the NASA / ESA Cassini mission, released on February 22nd, 2016. - are captured in this group photo from NASA's Cassini spacecraft released on Feb. 22. Tethys (660 miles across) appears above the rings, while Enceladus (313 miles across) sits just below center. Mimas (246 miles across) hangs below and to the left of Enceladus. This view looks toward the sunlit side of the rings and was acquired at a distance of approximately 837,000 miles from Enceladus.
Tethys, Enceladus and Mimas seen above and blow Saturn’s rings in a stunning image captured by the NASA / ESA Cassini mission, released on February 22nd, 2016. Tethys, 1056 km (660 mi) in diameter appears above the rings, with  Enceladus, 501 km (313 mi) across, just below them with Mimas, 393.6 km (246 mi) across below and to the left of Enceladus. Looking towards the sunlit side of the rings and was acquired at a distance of approx 1,339,000 km (837,000 mi) from Enceladus (credit: NASA / JPL)

The Sliding Surface of Mars

We’re all familiar with images of the surface of Mars, with the Tharsis volcanoes straddling the equator and the great gash of the Vallis Marineris just to the south. It’s a view seen in many orbital images of the planet, and one thought to have been more-or-less representative of the topography of Mars from the earliest times.

However, new studies by geomorphologists, geophysicists and climatologists led by a team of French scientists, suggest that the surface of the planet underwent a gigantic “tilt” of between 20 to 25 degrees some 3 to 3.5 billion years ago, drastically altering its appearance whilst also offering an explanation for one of the mysteries of Mars.

Mars as we know it today, Arsia Mons, Pavonis Mons, and Ascraeus Mons straddling the equator
Mars as we know it today, Arsia Mons, Pavonis Mons, and Ascraeus Mons straddling the equator, and part of the Tharsis Bulge, with massive Olympus Mons further to the north and west, and the gash of the Vallis Marineris to the south and east

While a process known as variations of obliquity can cause a planet’s axial tilt to shift  over large periods of time (Earth’s axial tilt of 23.4° is decreasing at the rate of about 47 minutes of arc per century, for example), this is not the cause of Mars’ shifting “face”. Rather it is the result of the massive Tharsis Bulge.

The largest volcanic dome in the solar system, Tharsis is a plateau some 5,000 km (3,125 mi) across and around 12 km (7.5 mi) thick, topped by the massive volcanoes of Tharis Montes: Arsia Mons, Pavonis Mons, and Ascraeus Mons. It formed over a period of roughly half a billion to a billion years, commencing around 3.7 billion years ago.

The French research suggests that as the Tharsis Bulge grew as a result of volcanic activity, so it gained considerable mass – perhaps a billion billion tonnes), which caused the crust and mantle of the planet to “slip” around the core, rather like turning the flesh of an apricot around its stone. Thus, Tharsis appears to have “dropped” to the equator from a latitude of around 20 degrees north, completely changing the face of Mars during its first 1 to 1.5 billion years of history – the time at which life might have arisen, if it arose at all.

Mars as it may have appeared around 3.5-3.7 years ago, prior to the Tharsis Bulge forming
Mars as it may have appeared around 3.5-3.7 years ago, prior to the Tharsis Bulge forming (credit: Didier Florentz, Université Paris-Sud)

While such a slippage had previously been suggested, notably through the work of Isamu Matsuyama of the University of Arizona in 2010, the French study is the first to offer definitive geomorphological evidence that this is the case. One of the major outcomes of the work is that it explains why Mars has huge and seemingly anomalous underground reservoirs of water ice located far from the poles. As the mantle and crust shifted, so they carried the frozen land which originally lay over the poles away from them, complete with the subsurface water and ice.

Overall, the study radically alters the generally accepted chronology of Mars, which has Tharsis forming before the before the widespread creation of rivers and water channels on Mars. now it appears that Tharsis formed at a time congruent with the existence of liquid water on Mars and the formation of river valleys and other water features. Thus, the volcanic activity on Tharsis may have actually contributed to the period of liquid stability on the planet.

The Methane Snows and Particle Clouds of Pluto

 enhanced color image is about 2,230 feet (680 meters) per pixel. The image measures approximately 280 miles (450 kilometers) long by 140 miles (225 kilometers) wide. It was obtained by New Horizons at a range of approximately 21,100 miles (33,900 kilometers) from Pluto, about 45 minutes before the spacecraft’s closest approach to Pluto on July 14, 2015.
Captured from a distance of 33,900 km (21,000 mi) from the point of closest approach to Pluto on July 14th, 2015, this New Horizons enhanced colour image reveals the ice-capped mountains of “Cthulhu Regio” in a strip some 450 x 225 km (280 x 140 mi). The image was taken about 45 minutes prior to closest approach (NASA/JPL / DHU?APL / SwRI)

The New Horizons team has discovered a chain of exotic snowcapped mountains stretching across the dark expanse on Pluto informally named “Cthulhu Regio”, one of the minor planet’s more identifiable features, and which stretches almost halfway around Pluto equator, some 3,000 km (1,850 mi) in length and some 750 km (450 mi) across, with one end abutting the ice-covered flats of “Sputnik Planum” I’ve previously written about in my coverage of New Horizons.

The high-resolution images show a mountain range in approximately 420 km ( 260 mi) long, the highest slopes of which are coated with a bright material that contrasts sharply with the dark red of the more usual dark red colouring of the region (thought to be the result of dark tholins, complex molecules initially formed by the reaction of methane and sunlight high in Pluto’s atmosphere, coating much of “Cthulhu Regio”. Scientists believe the white material could be methane which has condensed out of Pluto’s tenuous atmosphere to form ice, coating the peaks, much as ice can condense out of cold air on Earth to form frost. There has even been speculation that the white material is the result of methane ice condensing as “snow” and falling across the peaks.

Continue reading “Space Sunday: the Martian tilt and Plutonian clouds”

Space update: Charon’s ocean, Virgin’s spaceplane and your art in space

new-horizonThe Pluto – Charon system is, as I’ve reported through various Space Sunday reports, turning out to be far more remarkable a place than scientists ever imagined. While NASA’s New Horizons space vehicle, which zapped past both Pluto and Charon during its closest approach to both on July 14th, 2015.

On February 18th, NASA revealed the most recent surprise to be revealed by New Horizons: Charon may have once had a subsurface ocean that has long since frozen and expanded, pushing outward and causing the moon’s surface to stretch and fracture on a massive scale.

The side of Charon imaged by NASA’s probe is characterised by a system of “pull apart” tectonic faults, which are expressed as ridges, scarps and valleys—the latter sometimes reaching more than 6.5 kilometres (4 miles) deep. Charon’s tectonic landscape shows that, somehow, the moon expanded in its past, fracturing as it stretched.

The outer layer of Charon is primarily water ice. This layer was kept warm when the tiny world / moon was young by heat provided through the decay of radioactive elements, as well as Charon’s own internal heat of formation. Scientists say Charon could have been warm enough to cause the water ice to melt deep down, creating a subsurface ocean. However, as it cooled over time, this ocean would have frozen and expanded (as happens when water freezes), lifting the outermost layers of the moon and producing the massive chasms we see today.

A close-up of the canyons on Charon, Pluto's big moon, taken by New Horizons during its close approach to the Pluto system last July. Multiple views taken by New Horizons as it passed by Charon allow stereo measurements of topography, shown in the color-coded version of the image. The scale bar indicates relative elevation. Credits: NASA/JHUAPL/SwRI
A close-up of the canyons on Charon taken by New Horizons from a distance of 78,700 km (48,00 mi) and around 1 hour and 40 minutes before the spacecraft reach the point of its closest approach to Charon on July 14th, 2015. Multiple views taken by New Horizons as it passed by Charon allow stereo measurements of topography, shown in the colour-coded version of the image. The scale bar indicates relative elevation (image: NASA / JHU/ APL / SwRI

In an image gathered by the Long-Range Reconnaissance Imager (LORRI) in July 2015 and release by NASA on February 18th, reveals a vast equatorial belt of chasms on Charon. This network is around 1,800 km (1,100 mi) long and in places is 7.5 km (4.5 mi) deep. By comparison, the Grand Canyon is 446 km (277 mi) long and around 1.6 km (1 mile) deep.

The inset images on the picture show one section of the network of chasms, informally named “Serenity Chasma”, with a matching colour-coded topography map.  Measurements of “Serenity Chasma” strongly suggest Charon’s water ice layer may have been at least partially liquid in its early history, and has since refrozen.

SpaceShipTwo Unveiled

SpaceShipTwo VSS Unity, rolled-out on February 19th, 2016
SpaceShipTwo VSS Unity, rolled-out on February 19th, 2016 (image: Virgin Galactic)

Virgin Galactic, Sir Richard Branson’s private venture company which is aiming to become the world’s first commercial space line, offering fare-paying passengers sub-orbital flights into space. rolled out it new SpaceshipTwo vehicle on Friday February 19th.

The event came more than a year after the loss of the first SpaceShipTwo craft, the VSS Enterprise, in a tragic accident in which the craft broke up in mid-air on October 31st, 2014, killing co-pilot Michael Alsbury, and seriously injuring pilot Peter Siebold. At the time of the accident, several other figures involved in private sector space efforts were quick to point to Virgin Galactic’s use of nitrous-oxide as a vehicle propellant and to suggest corner-cutting by the company as causes of the accident.

However, after investigating the incident, the US National Safety Transportation Board (NTSB) drew the conclusion that the incident was largely the result of pilot error: the “feathering” mechanism designed to be used at the edge of space to allow the vehicle to gently re-enter the denser layers of Earth’s atmosphere was inadvertently deployed by co-pilot Alsbury, resulting in the immediate aerodynamic destabilisation and break-up of the vehicle. As a result of these findings, and as a part of a series of improvements made to the vehicle, the new SpaceShipTwo  includes a locking mechanism designed to prevent the feathering system being deployed in error.

VSS Unity is rolled out in a ceremony which saw it christened by Professor Stephen Hawking and Sir Richard Branson's year-old granddaughter
VSS Unity is rolled out in a ceremony which saw it christened by Professor Stephen Hawking and Sir Richard Branson’s year-old granddaughter (image: Virgin Galactic)

The new vehicle, christened VSS Unity by Professional Stephen Hawking (assisted by Branson’s year-old granddaughter), was rolled-out at a special media event held at  Virgin Galactic’s operations and flight facilities in the Mojave Desert, California. It marks the start of a long programme to get the vehicle to a point where it is ready to undertake its first powered flight.

This programme will include a series of ground tests of various vehicle systems, followed by taxi tests on the runway at the Mojave Air and Space Port. after these will come “captive carry” flights, where SpaceShipTwo remains attached to its WhiteKnightTwo carrier aircraft, then unpowered glide flights before the first in a series of powered test flights. While this test programme is not expected to be as protracted as the flight evaluation programme undertaken by VSS Enterprise prior to its crash, iy does mean that the company is not ready to provide any suggested dates by which fare-paying flights might commence.

Continue reading “Space update: Charon’s ocean, Virgin’s spaceplane and your art in space”

Space Sunday: Dream Chasers Falcons, and spacewalks

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: dunes, rockets and asteroids

CuriosityNASA’s Mar Science Laboratory rover, Curiosity, continues to perform the first up-close study ever conducted of extraterrestrial sand dunes as it slowly explores the slopes of “Mount Sharp” dubbed the “Bagnold Dunes”.

Located on the north-west slope of the mound which lies at the centre of Gale Crater, the dunes differ from those drifts and sand fields the rover has previously encountered on Mars in terms of both their size and height – some cover an area the size of a football field and are 2 storeys high – and their general shape, something which marks them out as “classic” sand dunes.

This latter point is most evident by the dunes exhibiting a steep, downwind slope, referred to as the slip face, and which exhibits certain features of its own, such as gain fall, ripples and grain flow, as well as the dune as a whole exhibiting typical features such as the horn and toe.

For the last couple of weeks, the rover has been working its way around one dune in particular, dubbed “Namib”, which is somewhat smaller than the “high dunes” images at the start of December, but which still rises to a height of some 5 metres (16 ft). The leeward side of “Namib” in particular demonstrates the classic features of a sand dune, and helps to confirm the fact that the dunes are slowly progressing down the slope of “Mount Sharp” at a rate of about 1 metre (39 inches) a year.

The leeward side of Namib:
The leeward side of “Namib”:Horn – where sand is escaping the main dune and escaping downhill, as indicated by the ripples; Toe – the downwind extent of the dune; ripples – signs of the sand bouncing sideways over the dune as the wind blows it downslope towards the horn;  Brink – the ridge between the windward, gentle slope of the dune and the leeward, steeper slope of the dune; Grail Fall – areas where sand is blown / falls from the brink and comes to rest on the leeward slope; Gain Flow – tongue-like area indicating where large amounts of sand have slumped down the side of the dune towards the toe, again indicative of a dune in motion

The dune-investigation campaign is designed to increase understanding about how wind moves and sorts grains of sand in an environment with less gravity and much less atmosphere than well-studied dune fields on Earth. Such an understanding of how the wind moves sand could lead to a clearer picture of how big a role the Martian 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.

This rather odd-looking image is a foreshortened 360-degree view of the area around Curiosity. In the immediate foregound is the rover's main deck, with the cylindrical, finned nuclear RTG at the back of it. Beyond this is the "Namib" dune, with a taller dune beyond it. The view was constructed froma series of images taken by the rover's Mastcam on December 18th, 2015 (Sol 1,197 on Mars), all of which have been white-balanced to present the view under normal Earth daylight conditions
This rather odd-looking image is a foreshortened 360-degree view of the area around Curiosity. In the immediate foreground is the rover’s main deck, with the cylindrical, finned nuclear RTG at the back of it. Beyond this is the “Namib” dune, with a taller dune beyond it. The view was constructed from a series of images taken by the rover’s Mastcam on December 18th, 2015 (Sol 1,197 on Mars), all of which have been white-balanced to present the view under normal Earth daylight conditions

Back to Sea for SpaceX

SpaceX, the private space launch company, is keeping itself busy. Following the successful launch of the Orbcomm mission from Florida’s Cape Canaveral Air force Station, together with the successful recovery of the first stage of the booster when it flew back to the Cape and performed a flawless vertical landing, the company’s next launch is scheduled for Sunday, January 17th.

The launch will take place from Vandenberg Air force Base, California, which is the company’s Pacific Coast launch operations centre. The primary aim of the mission is to place the third in a series of joint U.S.-European satellites into a near-polar orbit (for which Vandenberg AFB is ideally suited, as a polar launch from there does not pass over inhabited land during ascent, lessening the risk to human lives should a launch vehicle suffer a failure).

The Jason-3 series of missions is part of a very long-term series of studies (started in 1992) to study the topography of the ocean surface (i.e. the formation and movement of waves and the troughs between them), which can provide scientists with critical information about circulation patterns in the ocean, and about both global and regional changes in sea level and the climate implications of a warming world.

Jason-3, the latest in a series of joint US-European satellites studying the topography of the ocean's surface, is due for launch on December 17th, 2016, using a SpaceX Falcon 9 1.1 rocket
Jason-3, the latest in a series of joint US-European satellites studying the topography of the ocean’s surface, is due for launch on December 17th, 2016, using a SpaceX Falcon 9 1.1 rocket (image: NASA / CNES)

The polar orbit used for this kind of earth-observing mission, being almost perpendicular to the Earth’s rotation, allows the spacecraft to at some point travel over almost every part of the world’s oceans, vastly increasing its ability to gather data when compared to a vehicle in an equatorial orbit.

What is also significant about the mission is that it will use a SpaceX Falcon 9 1.1 booster, the first stage of which will once again attempt to return to Earth and make a safe landing. However, unlike the December 2015, this landing will once again be at sea, using a SpaceX droneship landing platform.

Continue reading “Space Sunday: dunes, rockets and asteroids”