Space Sunday: the last goodbye, super-Earths and spaceplanes

September 14th, 2017. One of the final images captured by Cassini as it approaches Saturn for the last time, with mysterious Enceladus visible beyond the limb of the planet. The thin blue haze seen in the picture is the atmosphere above Saturn’s cloud tops, where the spacecraft finally disintegrated. Credit: NASA/JPL / Space Science Institute

At 12:55 UT (13:55 BST, 08:55 EST, 05:55 PDT) the very last signal was received from the NASA / ESA Cassini spacecraft as it entered the upper reaches of Saturn’s atmosphere before disintegrating and burning-up. It was received 83 by NASA’s ground station near Canberra, Australia, 83 minutes after being transmitted – by which time the probe had already been destroyed.

At mission control, at the Jet Propulsion Laboratory, operated jointly by NASA and Caltech in Pasadena, California, it was an emotional moment. For many, the mission had been a part of their daily lives for nigh-on 20 years.

“The signal from the spacecraft is gone and, within the next 45 seconds, so will be the spacecraft,” Cassini programme manager Earl Maize announced, his voice catching, to the team gathered in mission control. “I’m going to call this the end of mission.” He then turned to Spacecraft Operations Team manager Julie Webster and hugged her, before giving Linda Spilker, the Cassini Project Scientist a hug as well. That loss of signal came within 30 seconds of the time predicted ahead of Cassini’s final dive.

Cassini Project Manager Earl Maize (centre left) and Spacecraft Operations Team Manager Julie Webster embrace after the Cassini spacecraft plunged into Saturn, Friday, September. 15, 2017. Credit: NASA / Joel Kowsky

As I reported last week, The Cassini-Huygens mission has been an incredible voyage of discovery, revealing so much about Saturn, its rings and retinue of moons, including hints on the evolution of life itself and revealing how moons Titan and Eceladus may have all the right conditions to support basic life while Tethys could – like Enceladus – have a liquid water ocean under its ice.

Cassini’s final approach commenced on September 11th, as it started back towards Saturn having made a final pass between the planet and its rings and looping away from both the week before. Passing by Titan, and once more using the moon’s gravity to push it into the correct trajectory, the probe headed back for its final encounter with Saturn. The Titan fly-by presented a last opportunity to image and study the moon before Cassini’s imaging system was focused on Saturn for the first part of the final approach. Imaging Saturn ended on Thursday, September 14th as the vehicle re-oriented itself to gather as much data on its brief passage into the upper reaches of Saturn’s atmosphere.

Time line of the final plunge. Credit: NASA

As I’ve previously noted in my Cassini mission updates, the primary reason for sending the probe into Saturn’s atmosphere was because it had exhausted almost all of its on-board fuel supplies used to orient itself and to adjust its flight through the Saturnian system, and the mission team didn’t want to leave the probe tumbling around Saturn’s moons where it might one day impact one of them and contaminate it with both Earthly microbes which may be dormant inside the vehicle, and which radioactive debris from its electrical power generators.

However, an alternative would have been to use the last of the vehicle’s fuel to boost it away from Saturn and out into space, but the scientific return promised by a final plunge into the planet was too good to refuse. “Saturn was so compelling, so exciting, and the mission we finally came up with was so rich scientifically that we just couldn’t — we had to finish up at Saturn, not some place else.” Earl Maize stated during a press conference after the probe’s fiery end.

There are currently no planned missions that will follow Cassini-Huygens to Saturn, although there are proposals to send missions to Titan. However, while the active part of the mission has come to an end, it’s not an end of the mission’s science.

“We have collected this treasure trove of data, so we have decades of additional work ahead of us,” Linda Spilker, the Cassini Mission Scientist said. “With this fire hose of data coming back basically every day, we have only been able to skim the cream off the top of the best images and data. But imagine how many new discoveries we haven’t made yet! The search for a more complete understanding of the Saturn system continues, and we leave that legacy to those who come after, as we dream of future missions to continue the exploration we began.”

As a closing note – for now – it’s not often that a space mission gains an official music video; but Cassini-Huygen has been a major inspiration for many over the past two decades, it has earned not one, but three official music videos which form a suite of music by three composes: Iniziare (Italian: “to start” by Sleeping At Last, aka Ryan O’Neal), Kanna (Icelandic: “Explore” by Sarah Schachner) and Amaiera (“end” or “stop” by Joseph Trapanese). I’ve embedded the first part below.

SpaceX Launch X-37B

On Thursday, September 7th, a SpaceX Falcon 9 booster launched the US Air Force X-37B secret mini-shuttle into orbit ahead of the Florida coast being hit by hurricane Irma. It marked the 13th Falcon 9 launch of 2017, and the fifth flight overall for the X-37B.

The USAF’s X-37B Orbital Test Vehicle (OTV) on the runway at Kennedy Space Centre, May 7th, 2017, at the end of the 717-day OTV-4 mission, being “safed” by a Boeing team in protective suits to guard against harmful fumes and gases given off by the vehicle. Credit: USAF

OTv-5 (Orbital Test Vehicle flight 5) saw the automated spaceplane placed into a higher inclination orbit than previous missions – thus expanding the vehicle’s flight envelope. However, in keeping with previous missions, the USAF has remained mostly silent on the mission’s objectives or its intended duration, revealing only that one experiment flying is the Advanced Structurally Embedded Thermal Spreader II (ASETS-II), which will measure the performance of an oscillating heat pipe.

Previous OTV missions have been long-duration flights, with the maiden flight in 2010 lasting 224 days and 9 hours, which each mission lasting longer than the last, with the last mission completed, OTV-4,  totalling 717 days and 20 hours in orbit. The flights have, up until now, alternated between the two known X-37B vehicles, so although it has not been confirmed, it is believed this mission is being carried out by the first X-37B to fly in space.

The SpaceX Falcon 9 first stage descends to a safe landing at Cape Canaveral Air Force Station after sending the X-37B OTV on its way to orbit on September 7th, 2017. Credit: Ken Kremer

The launch took place from Kennedy Space Centre’s Launch pad 39A, which SpaceX has leased from the US space agency and refurbished to handle Falcon 9 and Falcon Heavy launches – and which is now liable to be the pad from which the company’s massive ITS super-heavy rocket will depart when it enters operations in the 2020s. After separating from the upper stage and its cargo, the Falcon 9 first stage performed a “burn-back” manoeuvre and flew back to SpaceX’s dedicated Landing Zone-1 (LZ-1) at Cape Canaveral Air Force Station alongside Kennedy Space Centre, offering spectators a superb view of the landing.

Continue reading “Space Sunday: the last goodbye, super-Earths and spaceplanes”

Sansar Product Meetings 2017: week #37

City Park by Lex4Art, the location for the Sansar product meet-ups, Friday, September 15th

The following notes are taken from the Sansar Product Meetings held on Friday, September 15th. These meetings are held every Friday at 9:30am PDT and 4:00pm PDT, and are open to all. There is no set agenda (currently), and the meetings are a mix of voice and text. Venues change on a weekly basis, and are announced in the Meet-up Announcements. The September 15th meeting took place at City Park, by Lex4Art. The official meeting notes are published in the week following each pair of meetings.

Cara (morning session) and Carolyn (afternoon session) from the product team attended the meetings. However, Cara’s microphone pick-up was not particularly good; couple with background office noises, this made it hard to hear her at the morning session.

Release Feedback

It has been a week since the August / September release, and feedback is now coming in, with some issues being highlighted, including:

  • Terrain Editor: some users have found that when incorporating terrain plains into their builds, everything works OK in Edit mode, but on publishing assorted problems can occur, including not being able to access the published experience. Suggestions for checking the issue is to try re-publishing the experience without the new terrain element to ensure it is accessible / eliminating the problems, and try publishing a simple experience with edited terrain / recreate the existing scene to see if the issues repro. Experiences exhibiting this issue should not be deleted.
  • Undesired object movement / re-positioning:
    • Some users have found that objects which appear correctly positioned and aligned when editing a scene can appear misaligned / out-of-place (see here), although one person indicated they were seeing similar prior to the release.
    • Others have reported objects in both edit and published mode have relocated themselves following the release.
    • Some have found that while a published experience looks correct, if they go to Edit mode to edit the scene, the objects are all incorrectly placed. Apparently, the support response to this issue is to delete all affected items with new versions from inventory – although this is subject to verification.
  • Physics Changes: At least one user has noticed what might be physics changes since the update, with the pins in his bowling alley displaying a persistent wobble.
  • Scripting:
    • Script breakage:some users found their scripts were broken following the update, requiring they be replaced.
    • The LLCameraForward camera vector behaviour is no longer consistently tracking the movements in third-person view (although it is still working as expected in first-person).
    • Trigger Volumes have been reported as not working for one of the headset hand controllers (not clear if this is the Oculus Touch or the Vive hand controllers). Details on the issue weren’t clear at the meeting. This is now being looked at by the Lab.
  • Avatar VR Shuffle: when a user in VR mode enters first-person view, their avatar starts performing a strange little shuffling dance, which stops when exiting back into third-person. This might be related to a known issue when VR first-person view can result in the avatar moving around a little when it is supposed to be standing still.
  • Scene Objects Window: there is a bug which prevents users from scrolling all the way to the end of a long list of object containers when using the scene objects window in Edit mode, which can leave items and options unreachable. The Lab has noticed the same issue and are working on a fix.
  • Edit mode font size: while not specific to this release, there have been complaints that the default font in the Edit mode UI is too small for some people to comfortably read.
  • Streaming: only supports a single stream at a time without updating the scene and re-publishing the experience. For Sansar to work with music events featuring multiple artists / DJs, this will need an update to support multiple streams. While not on the roadmap for immediate delivery, the Lab is considering “avatar emitters”, which would allow sounds from specific artists or presenters at a talk, etc., to be heard throughout an experience.

It’s generally requested that all reproducible issues are reported on the issues forum, together with updates as people further test things.

People gather beneath the media screens at one end of the park

Sansar Roadmap and Work in-Hand / Being Planned

The public roadmap is approaching a point where it can be released. However, this will not be a blow-by-blow of everything that is coming and precise dates. Rather, it will provide a high-level overview of significant releases – avatar customisation, further terrain editing capabilities, clothing and fashion design capabilities, etc., together with indicators of when they may / should be appearing in releases. Some of the current work either in-hand or being planned includes:

  • Atlas improvements: the ability to search the client version of the Sansar Atlas (the web version can already be searched), hopefully making it easier to location / discover experiences of interest. This should be in the next Sansar release.
  • Height Maps: as noted with the August / September release, a planned update to the terrain system will be the ability for users to upload their own custom height maps (not clear if RAW files will also be possible), and custom textures with terrain.
  • Making text chat visible to users in VR mode: this is currently being worked on, a may appear “in a couple of months”.
  • Desktop interaction: the foundations are being laid to allow Desktop mode users have greater interaction with in-scene objects.
  • Avatar identification in Desktop mode: the ability for users in Desktop mode to more easily identify other avatars. No time line on availability as yet.
  • Social capabilities: further social capabilities are being planned, including group-like capabilities. However, details are not clear (again) on what form these will take or when they will be available.
  • Collaborative building: this is being actively worked on, however, it is dependent upon a number of other factors (e.g. the permissions system). So again, no time line on when it might appear as yet.
  • Better inventory organisation: this is also in the planning phase, is a part of the roadmap, but specifics have yet to be released on what it will be, nor is there a time line. This is already proving to be a major pinch-point for creators, as there is no means to organise via folders or rename inventory items or even search inventory, etc., and is thus impacting people’s ability / drive to create.


The meeting saw a couple of new requests made:

  • Texture Atlas support: a texture atlas allows for easy re-use of textures across objects / UV maps. This sort-of sits between texturing and modelling, and allows textures to be-reused across multiple objects / UVs without multiple draw calls to the system. This is one of an ongoing series of questions around textures in Sansar and future plans for textures / materials / reflections, etc. Jenn and Cara are going to look at getting one of the Sansar team directly involved in this side of the work to come to a meeting and answer questions.
  • More attachments / support for multiple attachments on a single point: currently, there is only one attachment point on Sansar avatars (the neck).  This is because multiple attachment points proved to be buggy when first deployed. While such things need to be constrained (there is already a complexity limit when uploading attachments), having more attachment points  / the ability to attach more than one item to an attachment point is seen as needed by some. Further work on the avatar as a whole is planned, and this might include improvements to attachment handling.

There is also the request for LL to provide a means for people to offer updates to their products. This is liable to be a topic for detailed discussion at the Sansar Store focus meeting, due to take place at the end of September 2017.

Continue reading “Sansar Product Meetings 2017: week #37”

There be pirates at Seanchai Library in Second Life!

The Pirate Docks await the pleasure of your company for Pirate Sunday!

It’s time to kick-off another week of storytelling in Voice by the staff and volunteers at the Seanchai Library. As always, all times SLT, and events are held at the Library’s home at Holly Kai Park, unless otherwise indicated.

It is International Talk Like A Pirate Day on Tuesday, September 19th, ARRRR! And Seanchai Library is marking the event with a week of salty tales and more!

Sunday, September 17th: Pirate Sunday!


Take the teleport up to Seanchai Library’s pirate cove, where Kayden Oconnell, Aoife Lorefield, and Caledonia Skytower will regale you with tales of the skull and crossbones, cutlasses, treasure and more from the wild days of yore on the high seas!

14:30-16:30: MUSIC AND DANCE

Those enjoying the tales are invited to teleport down to The Pavilion at Holly Kai Park, which has been specially transformed into the Pirate Docks, where the music will flow for two hours and everyone (and their friends! Invite the all!) can dance the time away, quaff the grog, walk the decks (or plank!), shiver their timbers – and even fire off a cannon or two!

And if have a boat, why not sail over and enjoy the fun!

Pirate Sunday benefits Feed a Smile, supporting a school in Kenya founded and run by Brique Topaz 16 years ago through her German-based Live and Learn in Kenya charity. 100 Lindens equals approximately 30 cents in real world currency, which pays for one child’s meal. One third of all money raised for each month’s food budget is collected through donations made in Second Life – so, that’s another reason to come along!

** Pirate fancy dress to both these events strongly encouraged! **

Monday, September 18th 19:00: A Wizard of Earthsea

Gyro Muggins reads Ursula K. Le Guin’s first Earthsea Cycle. 

The boy is born on the island of Gont in the archipelago of Earthsea. This is a world infused with magic. Not everyone can control this magic, but those who know the right words and have a wizard soul can learn to utilize the power of the Earth to manipulate objects and events. The boy’s name is Duny; I can tell you that name because the name has no power over him. His true name is something he can only reveal to those he trusts absolutely beyond question.

I know his true name, but fair reader, I’m not sure yet that I can share it with you.

His aunt knows a few things, a handful of words, that can be used to bind things or call animals to her. Duny is particularly adept at calling falcons and other birds of prey. His agile mind soon surpasses what his aunt can teach him. He burns to know more. He is assigned to a mage, Ogion, who tries to teach him about the balance of magic with the Earth. There is always a cost for using magic. Understanding the levy for sorcery is the difference between being just impulsively talented and being wise about what you know.

(Commentary by Jeffrey Keeten.)

Tuesday, September 19th: International Talk Like a Pirate Day:

19:00: “George Was A Pirate…”

Selected adventures from R. Crap Mariner’s “George Canon” of 100-word stories (aka “drabbles”). With Corwyn Allen, Faerie Maven-Pralou, Kayden Oconnell, and Caledonia Skytower.

21:00: Meteor Mags – Hang My Body on the Pier

An original tale for a special “Late Night” on this special day, presented by the author, Matthew Howard.

** Pirate fancy dress to both these events strongly encouraged! **

Wednesday, September 20th, 19:00: Callahan’s Crosstime Saloon

Corwyn Allen reads Spider Robinson’s 1999 anthology.

callahansThe titular saloon is a haven for lost souls; a place where the patrons come for one drink and a chance for a second – but only if they offer an unburdening toast at the fireplace. Mike Callahan, the owner, never judges but sometimes advises in as few words as possible.

The stories in the volume are:

  • “The Guy with the Eyes”
  • “The Time-Traveler”
  • “The Centipede’s Dilemma”
  • “Two Heads Are Better Than One”
  • “The Law of Conservation of Pain”
  • “Just Dessert”
  • “A Voice is Heard in Ramah…”
  • “Unnatural Causes”
  • “The Wonderful Conspiracy”

Also presented in Kitely (hop://

Thursday, September 21st:

19:00:  PIRATES! – Tom Chist and the Treasure Box

With Shandon Loring (also presented in Kitely  hop://

21:00 Seanchai Late Night

Contemporary Sci-Fi-Fantasy with Finn Zeddmore.


Please check with the Seanchai Library’s blog for updates and for additions or changes to the week’s schedule.

The featured charity for August and September is Little Kids Rock, transforming lives by restoring, expanding, and innovating music education in schools.