Logos representative only and should not be seen as an endorsement / preference / recommendation
Updates from the week through to Sunday, February 5th, 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 Q(uality) viewer, version 6.6.9.577968, promoted Thursday, February 2, 2023.
Release channel cohorts:
Maintenance R RC viewer, version 6.6.10.578087, February 3 – translation updates and the return of slam bits.
Project viewers:
PBR Materials project viewer, version 7.0.0.577997, February 2, 2023. This viewer will only function on the following Aditi (beta grid) regions: Materials1; Materials Adult and Rumpus Room 1 through 4.
Perpetuity, February 2023 – click any image for full size
Camis Sierota (Camis Lee) and Tamara Sierota have once again redressed their homestead region of Perpetuity, returning it to what could be referred to as a North American theme, the region having spent a while dress as a European for part of late 2022 (see: A European styled Perpetuity in Second Life). However, unlike the last time I visited the region when it was dressed in something of an American theme (see: Perpetuity, USA in Second Life), for the start of 2023 the region offers a look of the Great Outdoors, and in doing so could represent almost anywhere in the wilds of the United States or Canada.
Surrounded by tall mountains on three sides which dip down to touch an open sea on the fourth, the region is cut through channel of water which may have started life as an inshore freshwater lake prior to the waters within finding a choice of routes outwards to reach those laying beyond its shores.
Perpetuity, February 2023
In doing so, it has split the land into two distinct areas, with an additional pair of low-lying banks of grass, shrubs and reeds poking slender fingers above the channel’s shallows. In meandering through the setting, these waters offer a place for the local wildlife to drink, and the local waterfowl and birds to swim and or / hunt.
Along both of the channel’s shores and on the pair of low banks might be found elk, bears, beaver, cranes and ducks, while overhead geese circle as if trying to determine the best approach for a watery touchdown and a bald eagle passes by, possibly looking for a perch from which it can watch for salmon or other fish straying too close to the surface and offering themselves as a possible catch of the day.
Perpetuity, February 2023The larger of the two landmasses is where the major signs of habitation might be found. To the east, sitting on a flat-topped rise in places buttressed by rocky cliffs, sits a small homestead ranch.
This is a place where sheep and dairy cattle are reared and horses kept, the latter sharing a pair of interconnected corals with the sheep. A single large barn provides indoor protection for the animals when needed as well as marking the landing point for visitors, whilst the stone-and-wood built ranch house is cosily furnished in keeping with its rustic western looks.
Perpetuity, February 2023
Westwards, the land splits, part of it sloping down to meet the waters of the inner channel, part of it rising as a rocky-sided hill crowned by a tall wooden watch tower. This overlooks the northern coastline as well as presenting a grandstand view back over the region towards the high mountains. Both the tower and the lowlands can be reached via a grassy trail running down from the ranch before it divides, and this can be followed on foot or horseback (take a ride from the rezzer at the barn or were your own if you have one).
Before reaching the water, the trail down slope – also used by local elk to reach and partake of the waters – passes by a small single-roomed cabin. Like the ranch house, the barn and the watch tower, this provides a place for folk to sit and relax and perhaps enjoy a cuddle or two. An outdoor fire pit and chair offer a superb view back eastwards along the water’s channel to where the spout of one of the two geysers the region boasts can be seen rising against the backdrop of a more distant headland.
Perpetuity, February 2023
The geysers sit at the eastern extent of the second of the main islands, sitting at a point where the land turns northwards to form a promontory helping to separate fresh water from salt. Their spouts rise from two circular hot springs, three smaller pools sitting between them, the group all hinting at a degree of volcanic activity relatively close by.
Behind them, the land rises quickly, punctured by outcrops of rock and home to more of the fir trees which also sit on the larger island. This is a place where more wildlife might be found, including bison and squirrels, moose and more elk. Along the trail rising up the island’s slope visitor will come across a litter of bear cubs who are busy helping themselves to the contents of picnic baskets, there being no sign of humans to keep guard over the bounty.
Perpetuity, February 2023
To the west, the island reaches a flat-topped brow overlooking the waters separating the region from the surrounding mountains and their hills. This hilltop is home to another cabin, this one larger than the one down by the channel below, offering a little more comfort to those who wish to rest here a while. An outdoor well provides fresh water whilst moose and chickens keep an eye on the property.
This is another setting perfectly put together by Camis and Tamara, one which is – as always with Perpetuity – highly photogenic, and is a place finished with a fitting sound scape.
Perpetuity, February 2023
With thanks to Shawn Shakespeare for the suggestion of a further re-visit.
An artist’s impression of a lunar base using the micro nuclear reactor (NMR) currently being developed by Rolls Royce. Three of the reactors can be seen in the right foreground, casting palm tree like shadows (the “palm frond” shadows are actually the reactors’ radiator panels). Three more of the reactors can be seen in the centre of the image. See below for more. Credit: Rolls Royce Aerospace
In my previous Space Sunday, I covered some of the renewed interest in nuclear propulsion for space missions – and it certainly is a hot topic (no pun intended). Just 24 hours after that article was published, NASA and the US Defense Advanced Research Projects Agency (DARPA) announced they had signed an interagency agreement to develop a nuclear-thermal propulsion (NTP) concept.
Referred to as the Demonstration Rocket for Agile Cislunar Operations (DRACO), the three-phase programme will look to develop and enhance an NTP propulsion system capable of operating between Earth and the Moon and eventually Earth and Mars, potentially enabling fast transit times to the latter measured in weeks rather than months. Nor is this simply a computer modelling exercise: the agencies plan to fly a demonstrator of the propulsion unit in early 2027.
As I noted in my previous piece, NTP uses a nuclear reactor to heat liquid hydrogen (LH2) propellant, turning it into ionized hydrogen gas (plasma) channelled through engine bells similar to those seen in chemical rockets to generate thrust. As I also noted, NTP for space vehicle propulsion is not new; both the US and the former Soviet Union both pursued NTP projects in the early days of the space race – most notably for the US with the Nuclear Engine for Rocket Vehicle Application (NERVA) project, successfully tested on the ground in 1963/64.
A conceptual rendering the DARPA-NASA nuclear thermal propulsion (NTP) test vehicle the agencies hope to fly in 2027
Per the agreement, NASA’s Space Technology Mission Directorate (STMD) will lead the technical development of the nuclear thermal engine, which will be integrated into a vehicle built by DARPA, with that agency leading the overall programme as the contracting authority. Both agencies will collaborate on the overall design of the engine.
DARPA and NASA have a long history of fruitful collaboration in advancing technologies for our respective goals, from the Saturn V rocket that took humans to the Moon for the first time to robotic servicing and refuelling of satellites. The space domain is critical to modern commerce, scientific discovery, and national security. The ability to accomplish leap-ahead advances in space technology through the DRACO nuclear thermal rocket program will be essential for more efficiently and quickly transporting material to the Moon and eventually, people to Mars.
– DARPA director Dr. Stefanie Tompkins
Meanwhile, on January 27th, 2023, the UK’s famed Rolls Royce teased details of its own foray into the space-based nuclear power / propulsion systems: the micro-nuclear reactor (MNR), an extremely robust, self-contained nuclear fission plant which could be used to supply power to bases on the Moon or Mars, or used as a core element in vehicle propulsion systems either individually or as multiple units to provide both thrust and system redundancy, if required.
Images suggest the Rolls Royce MNR is roughly 3 metres in length (excluding the heat radiators). Credit: Rolls Royce
Development of the MNR started as a result of a 2021 agreement between the United Kingdom Space Agency (UKSA) and Rolls Royce (RR) to study future nuclear power options in space exploration. However, the design for the unit builds on RR’s decades-long expertise in developing power plants for the Royal Navy’s nuclear submarine squadrons and, more particularly a project the company has been developing since 2015 to develop and build small modular reactor (SNRs) to meet the UK’s energy needs (SNRs are self-contained, less complex and lower cost alternative to current nuclear reactors).
Precise details of the size of the unit and its output have not been revealed, although images released by RR suggest a single MNR is around 3 metres in length. In discussing the system, the company indicated its designs have reached a point where it plans to have a full-scale demonstrator / prototype running by 2028.
The MNR forms a part of a broader space strategy from Rolls Royce, which also includes systems for high Mach propulsion systems (e.g. ramjets) which could be combined with rocket propulsion to reach orbit, and a new generation of radioisotope thermal generators (RTGs) for power generation on robotic explorer craft and surface system on the Moon and Mars. The overall aim of the strategy is to offer space agencies and the private sector the ability to easily integrate selected elements of RR’s product offerings into their space projects and programmes.
A rendering of a crew-carrying vehicle entering Mars orbit and using a series of Rolls Royce MNRs (outlined in blue) as a part of its propulsion and power system. Credit: Rolls Royce
Returning to NASA, as well as considering the nuclear option, the US agency has been researching the next generation of rocket engines – the rotating detonation rocket engine (RDRE) – and on January 24th, carried out a series of sustained ground tests of a prototype unit.
In a conventional rocket motor, fuel is expended by deflagration combustion – fuel and oxidiser are burnt to produce an energetic gas flow which is then directed through exhaust bells to generate subsonic thrust. With rotating detonation, fuel and oxidiser are injected into a circular channel (annulus). An igniter within the annulus then detonates the initial incoming mix, generating a shockwave which travels around the channel, returning to the point of injection.
At this point, more fuel is injected into the channel to be detonated by the existing shockwave. This increases the shockwave’s speed and force, and the cycle repeats over and over, the shockwave accelerating to supersonic speed, generating high pressures which can be constantly be directed out of the channel to form thrust through an exhaust system even as the shockwave maintains its momentum within the channel.
A still from NASA’s tests of its rotating detonation rocket engine. Note the “stepped” nature of the engine’s exhaust, a unique property of this type of motor. Credit: NASA
Whilst this may sound complicated, the upshot is that rotating detonation engines (RDREs) theoretically generate around 25% more thrust than conventional rocket motors, which directly translates to greater delta-V being imparted to vehicles departing Earth, so reducing flight times to the Moon and Mars and elsewhere in the solar system. RDEs could also be inherently less complex than subsonic brethren, reducing the mass of a launch vehicle’s propulsion system.
However, there are drawbacks; for example, the very nature of containing the growing force of the shockwave puts an RDRE under tremendous stress and they have been known to explode. They are also incredibly noisy when built at scale.
Both Russia and Japan have experimented with RDRE technology; in 2018, former Roscosmos chief Dmitry Rogozin claimed Russia had successfully developed the first phase of a 2-tonne class of liquid-fuelled RDRE, although this has yet to be substantiated. In 2021, Japan successfully tested a small-scale (112.4 lbf) RDRE in space, using it to propel the upper stage of a sounding rocket.
The NASA test, carried out at the Marshall Space Flight Centre, Alabama, is the first verified test of a full-scale RDRE. The demonstrator motor operated for a total of 10 minutes, reaching peak thrusts of some 4,000 lbf. This is fairly lightweight by rocket standards, but the aim of the test was not just to generate thrust, but to test the engine’s ability to withstand multiple firings and confirm that a copper alloy referred to as GRCop-42 developed by NASA specifically for use in RDRE engines, was up to the task of reducing the stress on the motor by more efficiently carrying the heat generated by the shockwave away from the annulus structure.
While tests with this motor will continue, NASA is now also moving to the construction of a large unit capable of a sustained 10,000 lbf – the same as mid-range rocket motors – to better understand the potential for RDREs to out-perform “traditional” rocket motors. If successful, it could pave the way for RDRE motors capable of match the output of large-scale engines like the RS-25 used by the Space Launch System (SLS) rocket (418,000 lbf).
Inara Pey: Living in a Modemworld 