2023 SL viewer release summaries week #20

Logos representative only and should not be seen as an endorsement / preference / recommendation

Updates from the week through to Sunday, May 21st, 2023

This summary is generally published every Monday, and is a list of SL viewer / client releases (official and TPV) made during the previous week. When reading it, please note:

  • It is based on my Current Viewer Releases Page, a list of all Second Life viewers and clients that are in popular use (and of which I am aware), and which are recognised as adhering to the TPV Policy. This page includes comprehensive links to download pages, blog notes, release notes, etc., as well as links to any / all reviews of specific viewers / clients made within this blog.
  • By its nature, this summary presented here will always be in arrears, please refer to the Current Viewer Release Page for more up-to-date information.
  • Note that for purposes of length, TPV test viewers, preview / beta viewers / nightly builds are generally not recorded in these summaries.

Official LL Viewers

  • Release viewer: Maintenance S RC viewer, version 6.6.12.579987, dated May 11, promoted May 16.
  • Release channel cohorts (please see my notes on manually installing RC viewer versions if you wish to install any release candidate(s) yourself).
    • glTF / PBR Materials project viewer, version 7.0.0.580085,  May 16
  • Project viewers:
    • No updates.

LL Viewer Resources

Third-party Viewers

V6-style

  • No updates.

V1-style

  • No updates.

Mobile / Other Clients

  • No updates.

Additional TPV Resources

Related Links

Memories, Friendship, Love, and Art in Second Life

Terrygold: My Friends, May 2023

Terrygold has always been and complex and expressive artist, her work often touching on matters of politics, ecology, the environment and more, her installations often a treatise of a theme intended (and succeeding) in getting the grey matter going. Some of her more recent works – Empty Chairs, Rain, I Would –  have contained autobiographical elements and reflections on life.

Such is the case – if only in part, perhaps – with My Friend, an installation which opened on May 20th. Given that they are somewhat autobiographical, these more recent installations can be difficult to follow; not because the narrative is particularly confusing, but simply because the subject matter is so personal. Such is the case with My Friend; but also, like Empty Chairs, Rain, and I Would, it has a message that can resonate deeply.

Terrygold: My Friends, May 2023

However, before getting into the installation itself, a quick detour into viewer settings. Terry’s work relies heavily on ambience, and the local environment is an important part in My Friend, so make sure you have your viewer set to Use Shared Environment (World → Environment →), and that Advanced Lighting Model (ALM) is enabled (Preferences → Graphics). Terry also advises the Shadows are set to Sun/Moon+Projectors, which can place an additional render load on a system; however, as this appears to be for the projected lights – which work just as well with just ALM enabled, so don’t fret if your system cannot hand Shadows. For the benefit of other, do please remove any facelights.

The installation combines three elements – a story presented in text, 2D images, and 3D dioramas, which in turn are combined into three parts. In the first, the story and images continue the broader narrative found in Terry’s earlier instalments, the narrative mixing with images to present the opening idea of how life can be shaped by memories and dreams. From here, on turning a corner, the story segues into a different narrative, one which may well leave the more autobiographic elements behind. It deals with reflections and memories of a lost friendship – and what might have been a first, and ultimately unrequited / lost, love. Finally, and on the upper level of the installation, we are invited to share in some of the memories that form recollections of that friendship.

Terrygold: My Friends, May 2023

The darkened environment reflects both the subtext of dreams used to open the installation and the fact that for many of us, memories most vividly come at night, in the darkened period between the lights going out and sleep arriving, leaping out unbidden. Here, the darkness of the setting causes the images Terry uses to illustrate her story do much the same: their  muted colours leaping from wall to eyes, reflecting that way in which those memories mentioned above flash into being.

In travelling through the art and story, we are drawn into a tale of a precious friendship held by one person towards another, and the mixing of positive and negative emotions that so often ebb and flow through the interactions which mark that friendship, and its eventual – perhaps inevitable – end. I don’t want to spoil the story by saying too much; however, there are elements throughout that will doubtless echo with us as we progresses through the lower level – for who has not had a certain friendship / love that has become framed by regret? What I will note is that all of the images presented have been created in Second Life and sans post-processing of any description, instead relying entirely on the available environment settings.

Terrygold: My Friends, May 2023

At the end of the story, two round openings offer access to a stairway leading to the upper level and a parkland sitting in darkness, pools of light illuminating little vignettes reflective of the story below (most notable the two bicycles).

Exactly how autobiographical the friendship elements within the My Friend might be is not for me to say; they could just as easily be born of the imagination. That is for Terrygold to reveal (or not!). But taken as a whole, My Friend is an evocation and nuanced story in both art and words.

  SLurl Details

Space Sunday: aiding three space telescopes

The Hubble Space Telescope, the Chandra X-Ray Observatory and the Spitzer Space Telescope. Credits: NASA

They are the grande dames, so to speak, of space-based astronomy, observatories launched into orbit around Earth and the Sun to provide us with unparalleled insight into the cosmos around us, born of ideas dating back to the early decades of the space age. They form three of the four elements of NASA’s Great Observatories programme, and all operated, or continue to operate well beyond their planned life spans; they are, of course, the Hubble Space Telescope (HST – launched in 1990), the Chandra X-Ray Observatory (CXO and formerly the Advanced X-ray Astrophysics Facility or AXAF – launched in 1999), and the Spitzer Space Telescope (SST, formerly the Space Infrared Telescope Facility or SIRTF – launched in 2003).

Today, only Hubble and Chandra remain operational. The fourth of the observatories (and 2nd to enter space after Hubble), the 16.3-tonne Compton Gamma Ray Observatory (CGRO), had its mission curtailed in June 2000, after just over 9 years, when it suffered an unrecoverable gyroscope failure. With fears raised that the failure of a second unit could leave the observatory unable to control its orientation, the decision was made to shut it down and de-orbit it in a controlled manner so it would break-up on entering the atmosphere and any surviving parts fall into the Pacific Ocean, rather than risk an uncontrolled re-entry which could shower major pieces of the observatory over populated areas.

Whilst the “youngest” of the surviving three observatories, Spitzer was placed into a “safe” mode in January 2020, ending 16.5 years of service. By then, the nature of the observatory’s orbit – it occupies a heliocentric orbit, effectively following Earth around the Sun  – were such that it was having to perform extreme rolls back and forth in order to carry out observations and then communicate with Earth, and these were affecting the ability of the solar arrays to gather enough energy to charge the on-board batteries. The “safe” mode meant that Spitzer could continue to recharge its batteries and maintain electrical current to its working instruments, potentially allowing it to be recovered in the future. However, while it is true that Hubble and Chandra continue to work, neither is without problems.

Hubble orbits close enough to Earth that even at over 500km, it is affected by atmospheric drag, causing it to very slowly but inexorably lose altitude. This used to be countered through the semi-regular servicing missions, when a space shuttle would rendezvous with HST to allow astronauts to carry out work, and then gently boost the telescope altitude using its thrusters. But the shuttle is no more, and the last such boost was in 2009 to 540 km; currently Hubble is at around 527 km, and at the present rate of decent, it will start to burn-up in another 10-15 years. However, a boost now could see Hubble – barring instrument / system failures – continue to operate through the 2050s.

The Hubble Space Telescope sitting on its holding platform in the cargo bay of the space shuttle Atlantis in 2009, seen through the orbiter’s rear deck windows during the 5th and final (and most extensive) servicing mission. Credit: NASA

Chandra, meanwhile, faces a different challenge. It lies in a highly elliptical orbit around the Earth, varying between 14,508 km at its closest and 134,527 km at its most distant. It has therefore been operating untended for its entire operational life, and is starting to show signs of wear and tear. In 2018, it suffered a glitch with one of the gyroscopes designed to keep it steady during observations (and orient it to look at stellar objects). Whilst the gyroscope was recovered, it was put into a reserve mode lest it fail again. This led to fears that should a second gyro fail, either orientation control might be lost if the 2018 gyro fail to come back on-line correctly to take over the work. Also, and while the main science instructions are in good order, they are aging and presenting concerns as to how well they are actually doing.

Ideas for both boosting Hubble’s orbit and carrying out a robotic servicing of Chandra have been floated for the last few years – but there are now signs both might actually get potentially life-extending missions.

In December 2022, NASA issued an RFI on how Hubble’s orbit could be boosted, and have received eight responses, one of which has also been publicly announced and would seem to offer potential. It involves two companies: Astroscale Holdings and Momentus Space, a US-based company. The former is in the business of clearing space junk from Earth’s orbit, and has already flown prototype vehicles capable of doing this in orbit. This includes the ability to carry tools to mate or grapple junk and then move them. Momentus, meanwhile, are in the satellite servicing business and recently demonstrated a small “space tug” in orbit that was largely successful in meeting its mission goals (7 out of nine small satellites deployed into individual orbits).

In their proposal, the two companies indicate Momentus would provide a variant of their tug, and Astroscale a dedicated capture tool designed to use the grapple holds on Hubble. Following launch, the Momentus craft would self-guide itself to Hubble’s orbit and rendezvous with it using the Astroscale mating tool. Once attached, the Momentus vehicle would use its thrusters to gently raise Hubble’s orbit by 50 km, then detach. The vehicle could then be used to remove orbital debris in orbits approaching Hubble, thus protecting it from the risk of collision.

NASA has yet to comment on any of the proposals received under the RFI, but the Momentus / Astroscale option, using equipment already being flight-tested and refined and which is of relatively low-cost, would appear to be a real option.

A similar, but more expensive and complex idea has been proposed by Northrop Grumman – the company effectively responsible for building Chandra – to help keep the X-Ray observatory going. This would involve the construction and deployment of a “mission extension vehicle”, a “space tug” capable of departing Earth and gradually extending and modifying its orbit to rendezvous with Chandra and link-up with it, taking over the operations related to orienting and steadying the platform using gyros, potentially extending the mission by decades.

This is important because Chandra has already proven invaluable in supporting the James Webb Space Telescope (JWST) which operates in the infra-red. The ability to observe targets in both X-ray and infra-red can reveal a lot more about them.

A set of X-ray images of regions of space – including supernova remnants and merging galaxies – captured by the Chandra X-ray Observatory, released by NASA in 2009 to celebrate the telescope’s 20th anniversary. Credit: CXC/NASA, SAO

NASA has given no word on whether it would finance such a mission, although Northrop Grumman has apparently forwarded the results of its own study on the idea to the US agency. However, given the most recent U.S. decadal survey in astrophysics, released in 2021, included mention of a new X-ray telescope to replace Chandra, a servicing mission – even one this complex – capable of extending Chandra’s operations for decades at a fraction of the cost of a new telescope, which itself would take years if not decades to develop, could be highly attractive.

Continue reading “Space Sunday: aiding three space telescopes”