Of Martian walkabouts, pictures from a comet, and getting ready to fly

CuriosityIn my last report on the Mars Science Laboratory, I mentioned that Curiosity has been on a geology “walkabout” up the slopes of the “Pahrump Hills” at the base of “Mount Sharp” (more correctly, Aeolis Mons). The zigzagging route up through the area took the rover from “Confidence Hills” and the location of the last drilling operation up to a point dubbed “Whale Rock”, the drive being used to gather information on potential points of interest for further detailed examination.

The exposed rocks in this transitional layering between the floor of Gale Crater, in which Curiosity arrived back in August 2012, and the higher slopes of “Mount Sharp” is expected to hold evidence about dramatic changes in the environmental evolution of Mars. Thus, the “walkabout”  – a common practice in field geology on Earth – was seen as the best means of carrying out a reasonable analysis of the area in order for the rover to be most efficiently targeted at specific locations of interest.

Curiosity’s walkabout, from “Confidence Hills” to “Whale Rock” in October, the rover is now working its way back to various points of interest for further studies

“We’ve seen a diversity of textures in this outcrop,” Curiosity’s deputy scientist Ashwin Vasavada (JPL) said of the drive. “Some parts finely layered and fine-grained, others more blocky with erosion-resistant ledges. Overlaid on that structure are compositional variations. Some of those variations were detected with our spectrometer. Others show themselves as apparent differences in cementation or as mineral veins. There’s a lot to study here.”

During the drive, Curiosity travelled some 110 metres, with an elevation of about 9 metres, using the Mastcam and the ChemCam (Chemistry and Camera) laser spectrometer system to inspect and test potential points of interest for more detailed examination at a later date. Since completing that drive, the rover has been working its way back through Pahrump Hills, this time examining specific targets using the robot-arm mounted Mars Hand Lens Imager (MAHLI) camera and spectrometer. Once this work has been completed, specific targets for in-depth analysis, including drilling for samples will for the core activity of a third pass through the area.

So far, two specific areas have been identified for detailed examination. The first, dubbed “Pelona” is a  fine-grained, finely layered rock close to the “Confidence Hills” drilling location. The second is a small erosion-resistant ridge dubbed “Pink Cliffs” the rover drove around on its way up the incline.

“Pink Cliffs” is roughly a metre (3ft) in length and appears to resist wind erosion more than the flatter plates around it.As such, it offers precisely the kind of mixed rock characteristics mission scientists want to investigate in order to better understand “Mount Sharp’s” composition. This image is a mosaic of 3 pictures captured on October 7th PDT, 2014 (Sol 771 for the rover) by Curiosity’s Mastcam. It has been white balanced to show the scene under normal Earth daylight lighting – click for full size.

Another target of investigation has been the edge of a series of sand and dust dunes right on the edge of “Pahrump Hills”.  In August 2014, Curiosity attempted to use these dunes as a means to more quickly access the “Pahrump Hills” area, but the effort had to be abandoned when it proved far harder for the rover to maintain traction than had been anticipated, particularly given the rover has successfully negotiated sandy dunes and ridges earlier in the mission. As a result, scientists are keep to understand more about the composition of the dunes.

On November 7th, Curiosity was ordered to venture onto the dunes very briefly in order to break the surface of one of the rippled dunes and expose the underlying layers of sand in an effort to better understand why the rover found the sand such hard going the first time around, and what might be within these wind-formed dunes that would prove to be so bothersome to driving over them. Data gathered from the drive is still being analysed.

Spanning roughly 1.2 metres from left to right, a wheel track breaks the surface of a dust sand dune ripple on the edge of “Pahrump Hiils”. The MSL science team hope the exposed material within the ripple will help them understand why Curiosity found these dunes hard-going when trying to cross them in August 2014.

The work in the “Pahrump Hills” area has given rise to concerns over one of the two lasers in the ChemCam instrument. As well as the main laser, known for “zapping” targets on the surface of Mars in order to reveal their chemical and mineral composition, the system uses a second laser, a continuous wave laser, used for focusing the ChemCam’s telescope to ensure the plasma flash of vaporised rock is properly imaged when the main laser fires. Data received on Earth when using the ChemCam to examine rocks on the first pass through “Pahrump Hills” suggests this smaller laser is weakening and may no longer be able to perform adequately.

If this is the case, the laser team plan to switch to using an auto-focus capability with the telescope so it will automatically focus itself on a few “targeting” shots from the main laser ahead of any data-gathering burst of fire, allowing for proper telescope calibration.

Continue reading “Of Martian walkabouts, pictures from a comet, and getting ready to fly”

The little lander that could – and did

Rosetta,
Rosetta,Philae and, behind them, comet 67P/Churyumov–Gerasimenko seen in an artist’s impression of the mission

It’s been a hectic 48 hours. On Wednesday, November 12th, after 10 years in space, travelling aboard its parent vehicle, Rosetta, the little lander Philae touched down on the surface of comet 67P/C-G/Churyumov–Gerasimenko (67P/C-G). It was the climax of an amazing space mission spanning two decades – and yet was to be just the beginning. Packed with instruments, it was hoped that Philae would immediately commence around 60 hours of intense scientific investigation, prior to its batteries discharging, causing it to switch to a solar-powered battery system.

Unfortunately, things haven’t quite worked out that way. As I’ve previously reported, the is very little in the way of gravity on the comet, so in order for Philae to avoid bouncing off of it when landing, several things had to happen the moment it touched the comet’s surface. As it turned out, two of these things didn’t happen, with the result that the lander did bounce – twice.

Where Philae may be (ESA image via BBC News) – Rosetta has yet to positively locate the lander beyond a rough estimate based on communications and signals received from the CONSERT instrument on the lander

The first time it rose to around 1 kilometre above the comet before descending once more in a bounce lasting and hour and fifty minutes, the second time it bounced for just seven minutes. Even so, both of these bounces meant the lander eventually came to rest about a kilometre away from its intended landing zone. What’s worse, rather than touching down in an area where it would received around 6-7 hours of sunlight a “day” as the comet tumbles through space, it arrived in an area where it was only receiving around 80-90 minutes of sunlight – meaning that it would be almost impossible to charge the solar-powered battery system.

As noted above, the mission was designed so that most of the core science could be carried out in the first 60 hours of the mission, just in case something like this occurred. Even so, in order to prolong the life of the vehicle, it would have been nice to move it into a greater area of sunlight. A means of doing this had also been built-in to Philae: the three landing legs can be flexed, allowing it to “hop”. But as images were returned to Earth by the Lander, it became apparent that one of the legs is not in contact with the ground, making such a hop problematic. After discussion, it was decided not to attempt to move the lander, but focus on trying to achieve the planned science objectives.

In this image released by ESA, a model of the Philae lander has been superimposed on images of the vehicle's shadowy surroundings as captured by the panoramic cameras mounted around the lander (image: Image: Sipa USA/Rex)
In this image released by ESA, a model of the Philae lander has been superimposed on images of the vehicle’s shadowy surroundings as captured by the panoramic cameras mounted around the lander (image: Image: Sipa USA/Rex)

As it turned out, the initial contact between the lander and the comet confused several of Philae’s instruments into “thinking” it had in fact landed, causing them to activate. These included the ROMAP magnetic field analyser, the MUPUS thermal mapper, the CONSERT radio sounding experiment and the SESAME sensors in the landing gear. Data received from these instruments, arriving on Earth some 30 minutes after initial contact with the comet, and the information which followed, help alert mission staff that something had gone wrong, and enabled them to subsequently piece together the events that occurred during the landing sequence, while the instruments continued to gather data and transmit it back to Earth via Rosetta.

On Friday, November 14th, the decision was taken to activate Philae’s sample-gathering drill, officially referred to as SD2. This had been postponed from the previous day, as the drill uses a lot of power. However, obtaining and analysing samples from inside the comet is a central part of the mission, the decision was made to push ahead with drilling operations.

Continue reading “The little lander that could – and did”

Philae: “I’m here, not there!”

The first image from the surface of a comet, returned to Earth by the Rosetta lander Philae, November 13th, 2014. image: ESA/Rosetta/Philae/CIVA
The first image from the surface of a comet, returned to Earth by the Rosetta lander Philae, November 12th, 2014. image: ESA/Rosetta/Philae/CIVA

Wednesday, November 12th saw a remarkable feat take place over 515,000,000 kilometres from Earth as a small robotic vehicle called Philae, and a part of the European Space Agency’s Rosetta mission, landed on the surface of a comet, marking the very first time this has ever been achieved.

As I reported, immediately following the landing, getting a vehicle to rendezvous with a comet, enter orbit around it and deploy a lander to its surface isn’t easy – Rosetta is a mission 21 years old, with the spacecraft spending a decade of that time flying through space.

Mission control personnel react to the first telemetry received from Philae on it's initial contact with the surface of comet 67P/C-G
Mission control personnel react to the first telemetry received from Philae on its initial contact with the surface of comet 67P/C-G

Immediately following the landing, telemetry revealed things hadn’t gone to plan, although the lander itself was unharmed. Essentially, part of the landing system – a pair of harpoons designed to tether the lander to the comet’s surface as a direct result of the very weak gravity there – failed to operate as expected. Telemetry has shown that the tensioning mechanism and the harpoon activation process started, but the harpoons themselves did not fire. As a result, the vehicle actually “bounced” after its initial touch-down.

The initial touch-down was at 15:33 UT – precisely on schedule and on target. However, as the harpoons failed, the lander rose back up – possibly by as much as a kilometre – above the comet, before finally striking the surface again, two hours later. This means that even while celebrations over the initial landing were going on here on Earth (the initial signal confirming touchdown taking some 30 minutes to reach Earth), Philae had yet to make its second contact with the comet.

Philae (circled in red) en route to its landing site on 67P/C-G (visible top right)
Philae (circled in red) en route to its landing site on 67P/C-G (visible top right)

This eventually happened at 17:26 UT, and was followed by another bounce, this one of a much lesser force, before the lander came to rest at 17:33 UT.

One of the consequences of this bouncing is that the lander is not actually in its designated landing zone – the comet is tumbling through space, and thus turning under the lander as it bounced. This means that while Rosetta and Philae are communicating with one another, the spacecraft’s orbital position around the comet is not optimal for the lander’s position, and is being refined to better suit Philae’s new location. An initial adjustment was made overnight on the 12th/13th November, and further adjust is likely to be made on Friday, November 14th. Currently, communications can occur between the two vehicles for just under 4 hours out of every 13.

Philae mission manager Stephan Ulamec explains where it is belived the lander resides, represented by the blue triangle (ESA press conference, Thursday, November 14th)
Philae mission manager Stephan Ulamec explains where it is believed the lander resides, represented by the blue triangle (ESA press conference, Thursday, November 14th)

This bouncing may explain why there was an initial problem with communications between the lander and the Rosetta spacecraft, as reported immediately after the initial landing telemetry was received: Rosetta was expecting Philae to be at a certain fixed position on the comet, whereas the lander was still in motion, and “moving away” from the landing site as the comet rotated. The task now is for Rosetta to visually locate the lander – which given the current orbital positioning, may take a little time; the next passage of the spacecraft over the region of the landing site will not start until 19:27 UT this evening. Mission planners hope the sunlight reflected by the lander’s solar panels might help in identifying Philae’s exact position.

A core worry for the mission team is that Philae has in fact come down in an area of shadow, possibly in a depression and close to one or two rocky “walls”, and it appears to only be receiving direct sunlight for around 90-120 mins as the comet tumbles, rather than the 6-7 hours planned with the target landing point. This potentially has serious implications for the lander’s power and science regime, although it is hoped that Philae might be able to adjust its position somewhat – the craft actually has the capability of “hopping” around by flexing its landing legs.

Continue reading “Philae: “I’m here, not there!””

To touch the origins of the solar system

Brave new world: the surface of comet 67P/C-G, upon which the European space Agency successfully landed a the robot vehicle Philae on Wednesday, November 12th, 2014 as a part of the Rosetta mission
Brave new world: the surface of comet 67P/C-G, upon which the European space Agency successfully landed a the robot vehicle Philae on Wednesday, November 12th, 2014 as a part of the Rosetta mission

“The biggest problem with success is that it looks easy, especially for those of us who have nothing to do.” Thus spoke Jean-Jacques Dordain on Wednesday, November 12th, just moments after it had been confirmed that a tiny robot vehicle called Philae had safely landed on the surface of a comet half a billion kilometres away from Earth.

That simple statement offers a subtle message on the huge achievement this landing represents. The Rosetta / Philae mission is the story of a 6 billion kilometre journey across space which has taken a decade to achieve, and which has involved some 20 countries. Yet the adventure is in many ways only now starting.

The Rosetta mission actually started 21 years ago, in 1993 when it was approved as the European Space Agency’s first long-term science programme. The aim of the mission being to reach back in time to the very foundations of the solar system by rendezvousing with, and landing on, a comet as it travel through the solar system.

An artist’s impression of Rosetta in space. It has already achieved a remarkable set of “firsts”, including the first solar-powered space probe to operate beyond the orbit of Mars. Philae, the lander, is the purple house shape on the front of the vehicle

Comets hold enormous scientific interest because they are, as far as can be determined, the oldest, most primitive bodies in the Solar System, preserving the earliest record of material from the nebula out of which our Sun and planets were formed. While the planets have gone through chemical and (in the cases of places like Earth), environmental and geological change, comets have remained almost unchanged through the millennia. What’s more, they likely played an important role in the evolution of at least some of the planets. There is already substantial evidence that comets probably brought much of the water in today’s oceans – and they may even have provided the complex organic molecules that may have played a crucial role in the evolution of life here.

The target for ESA’s attention is comet 67P/Churyumov–Gerasimenko (aka 67P/C-G), an odd-shaped body comprising two “lobes” joined together one  in what some in the media have at times referred to as the “rubber duck”. The larger of the two lobes measures some 4.1×3.2×1.3 kilometres in size (2.55×1.99×0.8 miles) and the smaller some 2.5×2.5×2 kilometres (1.6×1.6×1.2 miles). It is a “short period” comet, orbiting the Sun once every 6.4 years and most likely originating in the Kuiper belt, a disk of material from the early history of the solar system, orbiting the Sun at a distance of around 30-50 AU

The primary spacecraft in the mission, Rosetta, arrived in the vicinity of 67P/C-G on August 6th, 2014 becoming the first vehicle in history to successfully enter orbit around a comet. The major reason the mission took so long to reach the comet, having been launched in 2004, is that despite having a relatively short orbital period, 67P/C-G is travelling very fast and accelerating as is falls deeper into the Sun’s gravity well heading for perihelion (it is currently travelling at 18 kilometres (11.25 miles) a second and can reach velocities of 34 kilometres a second as it swings around the Sun). As it is impossible to launch a space vehicle is these velocities, Rosetta was launched on a trajectory which allowed it to fly by Earth twice (2005 and the end of 2007) and Mars once (early 2007), using the gravity of both planets to accelerate it and (in the case of the 2nd Earth fly by), swinging it onto an orbit where it would “chase” and eventually catch the comet.

It’s a long way from here to there: Rosetta’s flight from Earth to 67P/C-G (image via extremetech.com) – click for full size

Following its safe arrival, Rosetta settled into an orbit of some 30 kilometres around the comet in September, and began looking for a suitable place where Philae might land – because until the craft actually arrived in orbit around 67P/C-G, no-one had any idea of what it’s surface might look like. On 15 September 2014, ESA announced a region on the “head” of the “duck” had been selected for the landing, christening it Agilkia in keeping with a contest to name the landing site.

Further observations of the comet were carried out throughout September and October as an overall part of Rosetta’s mission and to gain as much information on the landing site itself. At the same time the spacecraft started manoeuvring itself in closer to the comet, dropping its orbit to just 10 km, ready for Philae’s delivery.

This image, captured by Rosetta on Wednesday, November 12th, shows the Philae lander as it starts its descent towards the comet
This image, captured by Rosetta on Wednesday, November 12th, shows the Philae lander as it starts its descent towards the comet

The landing operations commenced around 09:05 UT on Wednesday, November 12th, when Philae detached from Rosetta and started on its long gentle descent. Immediately following the separation, and due to Rosetta’s orbit around the comet, contact was almost immediately lost with the lander, leading to a tense 2 hour wait before communications could be re-established. This happened on cue, with the lander reporting all was OK.

Landing on a comet is no easy task. The gravity is almost non-existent, and there was a very real risk that Philae could, if it struck the surface of 67P/C-G too fast, simply bounce off. Hence the lander’s long, slow drop from the Rosetta spacecraft which the ESA mission scientists dubbed “the seven hours of terror” in recognition of the famous “seven minutes of terror” which marked the arrival of NASA’s Mars Science Laboratory Curiosity on Mars.

Continue reading “To touch the origins of the solar system”

2014 Opensimulator Community Conference: tune-in

A fascinating Gource visualisation posted by nebadon2025 charting the growth of the OpenSimulator project by code commits from core developers up until the time of the 2014 conference

Saturday, November 8th, and Sunday, November 9th mark the 2014 OpenSimulator Community Conference, which is being jointly run by AvaCon and the Overte Foundation. The weekend promises to be packed with talks, presentations, workshops and more; and while in-world registrations have sold out, it is not too late to register for the livestream broadcasts of the conference events.

The full programme can be found on the conference website, however, the keynote events comprise:

Saturday, November 8th, 07:30 SLT – OpenSimulator Developer Panel: featuring: Mic Bowman, Planning Committee, Intel Labs; Michael Cerqoni; Justin Clark-Casey, Overte Foundation; James Hughes, Founder, BlueWall Information Technologies, LLC; Oren Hurvitz, Co-Founder and VP R&D of Kitely; Crista Lopes, Overte Foundation and the University of California, Irvine; and Melanie Milland, Planning Committee, Avination. Together they will discuss  the future of the OpenSimulator platform, covering a range of issues including: the future of the Hypergrid, content licensing and permissions, scalability, project maturity, and more.

Saturday, November 8th, Noon SLT – Philip Rosedale: “How will we build an open platform for VR over the internet?”  a presentation exploring the future of the Metaverse and the challenges that lie ahead.

Sunday, November 9th, 07:30 SLT – Dr. Steve LaValle: “Virtual Reality. How real should it be?” Although VR has been researched for decades, many new challenges arise because of the ever-changing technology and the rising demand for new kinds of VR content.  This talk will highlight some of the ongoing technical challenges, including game development, user interfaces, perceptual psychology, and accurate head tracking.

The OSCC conference centre from the inaugrual 2013 conference
The OSCC conference centre from the inaugural 2013 conference

The conference website also lists all of the speakers attending the event, who will be participating in the keynote events and in the various conference tracks which will be running throughout the weekend:

  • The Business & Enterprise track will feature sessions that cover a broad range of uses related to doing business in and with OpenSimulator, such as those by grid hosts, third-party developers, private entrepreneurs, in-world and enterprise businesses, as well as corporations and organizations using OpenSimulator for marketing, fundraising, product research, focus groups, and more.
  • The Content & Community Track will feature sessions about all of the wonderful things that happen in-world. Building and content creation includes large-scale immersive art installations, ballet, theatre, performance art, machinima, literary arts, clothing designs, virtual fashions, architecture, music performances and other cultural expressions.  There are also communities for nearly every interest, including role-playing groups, science fiction communities, virtual towns and interest groups, historical explorations, religious and spiritual communities, book clubs, and so much more.
  • The Developers & Open Source track will cover the technical side of OpenSimulator, encompassing servers, viewers, external components, grid architecture, development, administration – anything that is necessary for the installation, operation and use of an OpenSimulator system.
  • The Research and Education Track will explore the ways in which OpenSimulator has become a platform for computationally understanding complex problems, characterizing personal interactions, and conveying information. This track seeks presentations regarding OpenSimulator use towards research applications in computer science, engineering, data visualization, ethnography, psychology, and economics. It will additionally feature sessions that cover a broad range of uses related to teaching and learning in and with OpenSimulator.
  • The Learning Lab will provide conference attendees the opportunity to explore and practice their virtual world skills, share their best OpenSimulator strategies, and experiment and discover diverse ways to use OpenSimulator to support creativity, knowledge production and self-expression. If you are a gamer or game enthusiast, this is the track for you! The Learning Lab features interactive sessions where attendees get to practice and apply skills hands-on, either in design or to play a game.

All of the event tracks are colour-code within the main programme guide, and their respective pages on the conference website include their livestream feeds for those who are watching events.

OSCC-6There will also be a number of social events taking pace during the conference and, for those of a daring disposition, the OpenMeta Quest: “Your mission, should you be brave enough to accept it, is to find 12 hexagon-shaped game tokens across 7 sims while matching your MetaKnowledge for prizes. Look for the Adventure Hippo to begin your journey.”

For those who have registered to attend the conference in-world, don’t forget you can find your way there via the log-in information page. When doing so, do not that the organisers recommend not using the OSCC viewer which was made available for the inaugural conference in 2013. Singularity is the recommended viewer for this year’s conference.

As well as the conference venue, the OSCC Grid includes a number of Expo Zone regions, featuring conference sponsors and community crowdfunder exhibits; a  Shopping Centre region; exhibits created by speakers in the Content & Community, Research & Education, and Learning Lab tracks.

All told, this packed weekend should be informative, fun and educational.

2014 banner

About the Organisers

The Overte Foundation is a non-profit organization that manages contribution agreements for the OpenSimulator project.  In the future, it will also act to promote and support both OpenSimulator and the wider open-source 3D virtual environment ecosystem.

AvaCon, Inc. is a 501(c)(3) non-profit organization dedicated to promoting the growth, enhancement, and development of the metaverse, virtual worlds, augmented reality, and 3D immersive and virtual spaces. We hold conventions and meetings to promote educational and scientific inquiry into these spaces, and to support organized fan activities, including performances, lectures, art, music, machinima, and much more. Our primary goal is to connect and support the diverse communities and practitioners involved in co-creating and using virtual worlds, and to educate the public and our constituents about the emerging ecosystem of technologies broadly known as the metaverse.

 Related links

High Fidelity launches documentation resource

HF-logoHigh Fidelity have opens the doors on their new documentation resource, which is intended to be a living resource for all things HiFi, and to which users involved in the current Alpha programme are invited to contribute and help maintain in order to see it develop and grow.

Introducing the new resource via a blog post, Dan Hope from High Fidelity states:

This section of our site covers everything from how to use Interface, to technical information about the underlying code and how to make scripts for it. We envision this as being the one-stop resource for everything HiFi.

What’s more, we want you to be a part of it. We’ve opened up Documentation to anyone who wants to contribute. The more the merrier. Or at least, the more the comprehensive … er. And accurater? Whatever, we’re better at software than pithy catchphrases. Basically, we think that the smart people out there are great at filling in holes we haven’t even noticed yet and lending their own experience to this knowledge base, which will eventually benefit everyone who wants to use it.

Already the wiki-style documentation area contains a general introduction and notes on documentation standards and contributions, a section to the HiFi coding standard; information on avatar standards, including use of mesh, the skeleton, rigging, etc; information on various APIs, a range of tutorials (such as how to build your avatar from MyAvatar), and client build instructions for both OS X and Windows.

The documentation resource includes a number of tutorials, including the basic creation of an avatar from the MyAvatar "default" (top); and also includes sections on standards, such as (bottom)
The documentation resource includes a number of tutorials, including the basic creation of an avatar from the MyAvatar “default” (top); and also includes a section on avatar standards, which includes information on the avatar construction, the skeleton, joint orients, rigging, etc. (bottom) – click for sull size

All told, it makes for an interesting resource, and Dan’s blog post covers the fact that the documentation project is also linked to the HiFi Worklist, allowing those who prefer not to write documentation to highlight areas of improvement / clarification or which need writing to those who enjoy contributing documentation, and being rewarded for their efforts.

As well as the link from the blog post, the documentation resource can be accessed from the High Fidelity website menu bar – so if you’re playing with HiFi, why not check it out?

Related Links

With thanks to Indigo Mertel for the pointer.