[Starlink] Starlink for Tonga?

Tue Apr 19 08:43:46 EDT 2022

I can probably comment on this.

The international cable went back into service on the 22nd of February, 
one day before the official commencement of service to Tonga by 
Starlink. Now I should probably add here that you can't order Starlink 
in Tonga - they sent 50-odd terminals care of the Tongan government, and 
that's it. Since these were no longer needed in Tongatapu, they were 
meant to go to various of the other islands. The "Reliance" wasn't able 
to recover much of the domestic cable and for lack of spares wasn't able 
to fix this one. It subsequently left the cable grounds, unable to dock 
in Tonga due to Covid restrictions. New cable is on order in France but 
probably about another 8 months away, minimum.

The biggest other islands, Vava'u and Ha'apai (more precisely, Lifuka - 
pronounced Li-Foo-Kah) already had other satellite links in service, and 
quite a bit of the GEO capacity directed at Tongatapu was shifted to 
them post Tongatapu's reconnection. So I'd expect most of the terminals 
to end up on some of the smaller islands - quite who gets to use them 
there I'm not privy to.

I understand that the government technician trying one of the Dishys in 
Tongatapu got 300 Mb/s down out of it, probably not surprising given 
that there wouldn't have been any competing traffic. Alas, I understand 
that service is a bit discontinuous, which is to be expected. I've tried 
to ask them as to how frequent and long the gaps are, but haven't had a 
response.

Tonga is still in Covid border closure mode, which means that few people 
are able to travel back and forth. One person that has been able to 
travel there is Shane Cronin, our volcanologist whom I was talking to, 
and he has been out of quarantine and is doing some interesting work up 
there - he even made the front page of the BBC World Service the other 
week: https://www.bbc.com/news/science-environment-61071293

First reports we've had from him suggest that there was still quite a 
bit of action after the international cable was knocked out. He's quite 
familiar with Hunga and was able to pinpoint which earlier eruptions 
various of the bits that were left had come from. He's been trying to 
get a record of vessels in the area at the time to get ash reports from 
BigOceanData and they promised to help. Alas, this coincided with a 
sudden surge in demand for superyacht tracking, which presumably has 
kept them busy, so we've not seen this data set yet. What we do know is 
that tsunami run-up on Tongatapu's West Coast was about 15 metres - far 
bigger than the waves whose videos still made it across the cable. Shane 
has also been able to look at some of the tsunami deposits and this is 
likely to yield some further insights.

Meanwhile, Emily Lane from NIWA has done some modelling around the 
pyroclastic density currents (turbidity currents of volcanic origin) 
that could have come off Hunga. The amount of material displacement 
involved in these simulations is in the several cubic kilometres! These 
show those flows actually reaching both cable grounds, the domestic one 
first. The domestic cable was essentially at the bottom of a trench 
straight downhill from Hunga and never stood a chance - not only do the 
simulations show the flow going across the trench eastbound, but then 
reflecting off the opposite side back into the trench before flowing out 
of the trench like water in a gutter. No wonder they couldn't find 
anything! The international cable grounds would have been reached later, 
first on the western side where they found the murky water weeks later, 
and then also on the eastern side, where the cable was pushed north. 
That said, according to the simulations, the first flow reaching the 
eastern side would have gotten there well before the outage, and doesn't 
quite explain the 5 km displacement. That said, the simulation was only 
run until international cable outage time, and there's some question as 
to the validity of these results generally as nobody knows whether the 
bathymetry in the area was still anywhere near what it used to be. NIWA 
and others are sending ships up to get clarity as to how the seafloor 
topography has changed in the area. Hunga used to have a huge caldera, 
and at this point, nobody knows whether it's still there, has subsided, 
or got blasted away. Lots of interesting science happening there at the 
moment.

On 20/04/2022 12:06 am, Dave Taht wrote:

> On Tue, Apr 19, 2022 at 4:57 AM Mike Puchol <mike at starlink.sx> wrote:
> >
> > Apologies for resurrecting an old thread, but I had totally missed 
> this post:
> >
> > 
> http://www.fintel.com.fj/pages.cfm/company/news/spacex-starlink-gateway--fintel.html 
> <http://www.fintel.com.fj/pages.cfm/company/news/spacex-starlink-gateway--fintel.html>
> >
> > It seems the gateway was setup in Fintel’s existing earth station, 
> four antennas only, however, and the cables in surface ducts.
>
> No apologies needed, in fact, does anyone know how well tonga is 
> recovering?
>
> > Best,
> >
> > Mike
> > On Feb 25, 2022, 20:12 +0300, Ulrich Speidel 
> <u.speidel at auckland.ac.nz>, wrote:
> >
> > I've heard nothing further about teleport establishment in Fiji, but 
> that doesn't mean that nothing has happened.
> >
> > Meanwhile, cable repair has progressed a good bit. The damage was 
> far greater than originally envisaged. On the international cable, 
> faults (complete cable ruptures and fibre damage) stretched over more 
> than 80 km. The cable ran entirely SOUTH of the Hunga Tonga Hunga 
> Ha'apai volcano (about 60 km away and shielded by a number of 
> submarine mounts for at least parts of the damaged section). Yet the 
> Reliance cable ship traced one disconnected cable piece end to about 5 
> km NORTH of its nominal route, found various sections had disappeared 
> completely, and recovered sections of up to 9 km at a time from the 
> seabed.
> >
> > A bog standard cable break requires two holding drives (or drags), 
> HD for short, to pick up each of the cable endpoints from the 
> seafloor. It also requires either an ROV dive to check if the cable 
> has completely separated at the fault position, or a cut if the cable 
> is still held together by the steel. That cut can be done either by 
> ROV as well, or if visibility doesn't permit ROV use, by a cutting 
> drive (CD). Any HD or CD requires the cable ship to tow a seafloor 
> grapnel / cutter device transversally across the cable, so they're 
> easy to spot on position traces. The Reliance did no fewer than seven 
> HD's in its eastern operations area near Tongatapu, where it worked 
> first. Visibility there was good (so ROV could be used), but damage 
> substantial.
> >
> > The ship then proceeded to the western end of the fault zone where 
> reflectometer measurements from the Suva end had found a fault. 
> Because of bad visibility, they did a CD followed by 2 HD's there, 
> then noticed that there was fibre damage along the cable to Suva, so 
> reeled that in and cut the damaged bit out.
> >
> > They then proceeded to put a "mini-system" together. Let me explain: 
> Enroute to Tonga, the Reliance stopped at Subcom's depot in Apia 
> (Samoa) to load whatever cable they had in store there. This included 
> spares not only for the Fiji-Tonga cable but also for various other 
> cable systems in the wider region. Reliance left Apia with about 80 km 
> of cable in total. The amount of cable that will need to be re-laid 
> along the damaged international section is 90 km (you need to allow 
> for a bit of cable lengthening due to slack being inserted when cable 
> ends are being brought up from 2000 m (6000 ft) or so below). This 
> means that the Reliance is re-using some of the cable recovered from 
> the damaged section, and the whole "mini-system" will be one long 
> stitch job. The damaged section also included a repeater worth 
> US$230k, which they were trying to recover and which was still missing 
> as of this morning - I've yet to hear from my contact as to whether 
> they were successful on the last recovery attempt today (they've left 
> the area after three drives and are heading West right now. The rest 
> of the mini-system was going to be laid after the repeater recovery 
> attempt (the overall success doesn't depend on the repeater being 
> found, but the final repair bill does). I thus expect the cable repair 
> to be completed in the next few days.
> >
> > The domestic cable is another story altogether, unfortunately. This 
> has a blind stretch of 77 km at present, as measured by optical 
> reflectometer from Tongatapu and Ha'apai (there was meant to be a 
> measurement from Vava'u yesterday but I haven't heard yet what this 
> revealed, the cable from Tongatapu has two fibre pairs, one of which 
> heads to each destination from a branching unit west of Ha'apai. That 
> said, once the international cable has been fixed, the Reliance won't 
> have enough cable left to complete the domestic job, even if some 
> cable bits could be recovered there. The next available stock of 
> suitable cable is in Europe, around 35-40 days one-way shipping away. 
> They intend to bridge this time gap via satellite (and I'm sure would 
> welcome a Starlink delegation with a teleport to connect to the 
> international cable, too, especially now that the Australian Navy gave 
> them Omicron along with their aid deliveries).
> >
> > I've been in close contact with our volcanology / geophysics 
> community here in NZ, who know the area well. The story of damage to 
> the international cable is now shaping up to be a pretty complex one. 
> What we know thus far is that it was neither the volcano's initial 
> blast nor the subsequent tsunami that killed the cable - the outage 
> began only well after the tsunami had hit. In all probability, it's 
> been a combination of submarine landslides and turbidite waves from a 
> variety of sources that hit hours and possibly many days after the 
> eruption. Finding that a cable piece has moved 5 km TOWARDS the 
> volcano points at an event south of the cable route, and the mix of 
> seafloor visibilities encountered by the Reliance points at there 
> having multiple events from multiple sources. There have been plenty 
> of quakes upwards of M4 and even an M6.2 in the wider area that could 
> have triggered slopes, especially with an extra layer of ash on them. 
> Turbidite waves can travel up to 1000 km, aren't anywhere near as fast 
> as a tsunami, and have long been known to have damaged cables in the 
> past (see B.C. Heezen and M. Ewing, Turbidity currents and submarine 
> slumps, and the 1929 Grand Banks Earthquake, American Journal of 
> Science, v. 250, pp 849-873, December 1952. This quake killed 12 
> submarine cables over more than 18 hours).
> >
> > Meanwhile, there's still limited satellite service in and out of 
> Tonga, but I can confirm that e-mails (even with attachments) make it 
> in and out OK.
> >
> > On 18/02/2022 8:27 pm, Mike Puchol wrote:
> >
> > Hi Daniel,
> >
> > I added it after there was a confirmation on Twitter that SpaceX 
> people were on the ground to set one up, and also, as two /27 blocks 
> (IPv4) have been assigned to Fiji’s capital, under the Sydney POP, and 
> they can be pinged.
> >
> > Wether it’s at the teleport or not, unsure, but for simulation, an 
> error of even a few km doesn’t really matter.
> >
> > Best,
> >
> > Mike
> > On Feb 18, 2022, 06:04 +0100, Daniel AJ Sokolov <daniel at falco.ca>, 
> wrote:
> >
> > On 2022-02-07 at 15:29, Mike Puchol wrote:
> >
> > As far as placing a gateway in Fiji, it already has a teleport
> > facility, which will have power and fibre (unless that one has been
> > taken out too?). Checkhttps://goo.gl/maps/6BYXf4R17yys7zNe9 
> <Checkhttps://goo.gl/maps/6BYXf4R17yys7zNe9>
> >
> >
> > Hey Mike, you put a "SUVA (Emergency)" ground station on starlink.sx.
> >
> > Is that for simulation, or has Starlink actually installed a ground
> > station in Fidschi by now? Would you have positive confirmation?
> >
> > Thank you
> > Daniel
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> > --
> > ****************************************************************
> > Dr. Ulrich Speidel
> >
> > School of Computer Science
> >
> > Room 303S.594 (City Campus)
> >
> > The University of Auckland
> > u.speidel at auckland.ac.nz
> > http://www.cs.auckland.ac.nz/~ulrich/ 
> <http://www.cs.auckland.ac.nz/~ulrich>
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> Dave Täht CEO, TekLibre, LLC

-- 
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Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)

The University of Auckland
u.speidel at auckland.ac.nz  
http://www.cs.auckland.ac.nz/~ulrich/
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