Well, I can't be all that far from you and on the strength of the met office prediction, I've set my alarm... :) I'll have to wander outside though.

Agreed..the first train was interesting, now....

Geostationary orbits are a long way away. I'm surprised there'd be any competition for those, but of course, they're limited to a fairly narrow latitude band.

If Jeff Bezos gets his way, the darn height will be about England stood on its south coast. Mind you, Starlink looks like they'd give flight crew a start.

Well I woke up. The sky was clear and I could see plenty of stars (for the city) - but I didn't see any train.

Maybe I wasn't looking at the right angle but I assumed if it was visible it would be impossible to miss?

I did go outside to see if they were overhead, but no luck there. If they were low then there's a row of street lights that probably did for me.

Did you see it?

The useful positions in the geostationary belt are just about full, and are much prized.

The daft thing about LEOs is that anyone with enough cash can chuck as many up into orbit as they choose and there seems to be no end to the process. The only control is on the frequencies they use. Astronomers just have to accept any problems they create for now or in the future.

No, sky was clear overhead but there was a certain milkiness in the sky which obscured all but the brightest stars as you looked more towards the horizon. I reckon they should have been about 30 or 40 degrees from directly overhead. I did see one satellite that was closer overhead, apparently from an earlier Starlink launch. Think I also saw a meteor! Blackbirds and robins were all trilling away merrily!

As Sallyann says the geostationary slots are a limited resource and quite valuable.

https://space.stackexchange.com/ques...tationary-belt

Thank you Wiggy, I just followed that link and spent a good half an hour realising how dumb I am. I also spent half of that trying to work out what "Tesseral" meant. I still cannot explain it, but if the pubs were open I would drop the word in conversation with certain of my drinking group to send them off on a wild goose chase of the term :}

Gordy's link is awesome but I suspect there is a flaw. If the satellites are in Earth's shadow then I doubt they can be seen.

A few hours after deep sunset or a few hours before twilight would be the ideal viewing time methinks.

Patchy cloud around my parts but the link suggested one of the trains would pass at 8:41pm - I saw a few moving things up there but not sure if I saw the train, have to wait for a clearer night.

Starlink
 

Sorry to offend all you astronomers but... my summer cabin is at 50N-122W in lovely British Columbia. No roads, no cell service, no utilities (except what I generate with solar.) My current connection with the world is Xplornet satellite. On a good day I get 2 to 3 Mbs download. This costs $129 month. I am anxiously awaiting my Starlink "dishy". Deposit is already paid. Beta testers are showing downloads of up to 300 Mbs. Same price as Xplornet. It's an easy decision for me.

Correct, and since the starlink satellites are in Low Earth orbit the period of time you, the observer, have dark skies, and the satellites above you are being illuminated by direct sunlight can quite short.

Over the months I've found the trains aren't always that easy spot, even from a dark sky site, so I wouldn't be at all surprised if one got missed from a light polluted area.

BTW I've used the Heavens Above site for years, I know the the interface isn't perhaps that fancy but it works.

App checked. Due overhead at 04:55 onwards - how exciting; at last something to look forward to, break the terminal Covid lockdown boredom!
Alarm set 04:45.
Slept fitfully till 04:40, pre-empted alarm (senior gentlemen's reasons, dealt with that).
Put on slippers - well one slipper actually - my son's dog that we seem to have adopted recently is a chronic slipper thief.
Crept carefully through the house, using a small torch to preserve night vision and so's not to wake the other half.
Re-checked the App - They're coming, They're coming, should be right overhead in a couple of minutes!!
Carefully unlocked and slid back the patio door.
Hopped out onto the cold patio slabs, in pyjamas and the one slipper, shivering slightly.
Looked skywards....for ten minutes. Didn't see a damned thing.
Went back to bed, feeling very cold and rather silly. :rolleyes:

Yes, me too... :{

Thanks, for that, wiggy. As you say, the geostationary belt is quite full. As has been mentioned, there is potential for interference if the geo satellites get close, but there is also a risk of collision, especially when you consider that some satellites stop operating and there's nothing you can do to move them, so you have to move others out of the way. Then there's whatever some company or country used to get their satellite into that orbit and might have been discarded.

One other thing to consider is that I suspect most people think that a satellite in geostationary orbit is stationary relative to someone on Earth. They aren't. Although they generally stay within a belt and close to where they should be, they actually do all sorts of loops and strange shapes while staying close to their supposed position from an Earth-observer's perspective. Considering all that, ground-based telescopes are used to detect if any operational satellites are in danger of collision and if they are, the ground-based observations are used to let the various companies know when and where to move their satellites.

A lot of work goes on behind the scenes to keep the world in touch!

Parking space problems in space. Who would have thought it?

Think of it more like a busy marina and a couple of boats getting loose. You know where everything is, all the boats are in a confined space, but you don't know what damage will be done until those boats are brought under control. I apologize for not knowing the maritime phrasing for this. But everyone else is worried that a rogue boat might hit their boat, and given enough warning they move their boats away from danger just to be safe!

Unfortunately, it's not like when we were kids using paddle boats and the scary guy with the loud hailer shouted "Come in number 3, your time is up!".

Huh, that sounds like my first job. 10/6 a week.

Now you mention it, of course, the Inmarsat relevent to the M370 made a huge 8 with the top loop smaller than the bottom. Yes, a lot of space taken up.

:ok:



You'l know a lot or all of this, for those that don't..

https://celestrak.com/columns/v04n07/

Thanks, wiggy! I did know this stuff since I've been involved in various projects since 2014 in observing orbital debris in high-earth orbit (i.e., geosynchronous orbit) but hadn't seen that web page before. It's very good and summarises things well. It's something I will definitely use in the future if and when I need to explain orbital debris and its potential effects. I think many people concentrate on orbital debris being a problem in low-earth orbit or something that's a threat to astronauts and space stations - which of course it is - but don't consider the threat to our whole satellite communication network.

Spacex has now launched 1300 satellites out if a planned 1500, at their current launch rate that should be finished in 6-8 weeks (which is mind blowing in itself).

At which point they will reportedly switch to regular polar launches out of Vandenberg - which should provide good views in the higher latitudes.

The first 10 were launched on 24th January Transporter-1 mission which launched 133 satellites for various customers. The 10 were launched to an altitude of approximately 500-kilometers above Earth to operate in Sun-Synchronous Orbit (SSO).

The polar satellites transfer data between them using lasers so no ground stations are needed in the polar regions.

https://www.theverge.com/2021/3/26/2...rctic-military

OneWeb and SpaceX are racing to beam internet to the Arctic

After the launch over the weekend Spacex now has over 1600 Starlink satellites in orbit. Now they’ve linked up with Google….

https://www.eetimes.com/spacex-expan...-google-cloud/

SpaceX Expands Starlink to Google Cloud

Starlink, the streak in the night sky launched by SpaceX, will connect with Google’s cloud infrastructure, enabling the satellite broadband network to deliver low-latency applications, data and other cloud services to network edge deployments.

SpaceX earlier signed a similar agreement to connect its Starlink constellation to Microsoft’s Azure cloud…. The cloud deals with Google and Microsoft illustrate the long-term goal of tapping the lucrative enterprise edge market.

Google said last week SpaceX will locate Starlink ground stations within its data centers to deliver applications to the network edge relayed by its growing satellite constellation.

The collaboration combines Google’s private cloud network with a satellite network service eventually aimed at corporate users, including those beyond the reach of terrestrial connections.….

Google and SpaceX said they expect to begin delivering the new edge services to corporate customers beginning in the second half of 2021.

SpaceX and Microsoft announced a partnership last fall that would link the Starlink broadband network to Azure modular data centers via satellite network provider SES.

Observers note the Google-SpaceX deal would create direct connections between the Starlink constellation via ground stations in Google data centers. Those direct connections would reduce latency and boost performance for streaming video and other enterprise applications……

Others stressed the deal would provide Starlink customers with faster connections to Google cloud servers.

Arianespace getting desperate to stop SpaceX getting so far ahead. Not sure how successful they’ll be appealing to the FCC however - and as far as I know there aren’t any European or UN bodies who have any powers to do so.

https://www.dailymail.co.uk/sciencet...ianespace.html

SpaceX launching thousands of satellites into low Earth orbit is 'unsustainable' and could give the Elon Musk-owned firm a monopoly in space, warns competitor Arianespace

Does someone think that Arianespace can stop SpaceX from launching their satellites? They've started a Starlink mission and must finish it.

Walking home a week or so ago, around 8pm, saw a group of four, then another, then another and so on for about 5 mins.

Given the Starlink constellation and similar projects objectively generate some real risks and several problems it's quite right that other spaceflight operators and international organisations should be raising concerns.

The astronomical world has for some time been utter p***** off that the quest for broadband appears to override any consideration regarding light pollution and the effect it has on some astronomical research...for example..

https://skyandtelescope.org/astronom...nomers-update/

https://www.nature.com/articles/d41586-020-02480-5

There are also concerns about the about of debris associated with the starlink satellites that is being dumped into Low Earth Orbit (LEO), increasing the risks for everybody operating in satellites and spacecraft at LEO "altitudes" ( It was discovered a few weeks back that the remote manipulator arm on the International Space station was been dinked by junk in the last few months)...

https://www.nature.com/articles/s41598-021-89909-7

Or maybe we should only be allowed to raise concerns over what the Chinese do with their cast off hardware?.......

The Starlink constellation is launched into an insertion orbit at 200km where the decay time to reentry is measured in days, before being raised to 500km where the life, if not maintained by using fuel, is about a decade.

The OneWeb constellation, for which Arianespace has just launched the latest batch, as launched into a 500km insertion orbit with a decay time of about a 10 years, before being raised to a 1200km orbit with a decay time of millennia.

Which is causing the greater long term problem?

Which, by the way, is why the FCC gave SpaceX permission for 2,800 more satellites - because they lowered their planned orbits from 1200km to the same 500km orbit as the present constellation.

https://spacenews.com/fcc-approves-s...-modification/

Fundamentally these is a real world physics issue here (Nature article refers, plenty more available) and interestingly even Viasat, an American company, has raised objections.

It's not quite a simple case of Arianespace/EU being desperate.....

Wiggy,

Viasat is another with a dog in the fight…… but also years behind…..

https://www.satellitetoday.com/busin...ng-q4-results/

…..Satellite operator Viasat reported record-breaking revenue increases and subscriber growth, and dropped a surprise revelation that it was scrapping its planned Medium-Earth Orbit (MEO) constellation for a new Low-Earth Orbit (LEO) constellation that will launch in approximately five to six years …..

I'm aware of the commercial side of this but objectively there are increasing concerns being expressed by many of the serious players in this game about the amount of debris being distributed into Earth orbit...

To borrow from Richard Feynman ""For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."

But many companies work on missions that'll clean up space debris, do you know it?

Yes, I know "it"...and do you know many such missions have been flown as of today, how much debris has actually been collected as of today, and how much debris needs to be collected?

Just to give you a clue according to some authorities such as NASA there are something like half a million objects of marble size or bigger in Low earth orbit..object the size of a paint fleck have damaged the windows of structures such as the ISS and Space Shuttle..it's a serious issue, there's potentially a heck of a clean up job and it's not even started...

It becomes clear why Viasat are keen to have LEO slots available - and they do have at least one powerful voice on their side…

https://www.c4isrnet.com/battlefield...-16-satellite/

Viasat to add military-grade encryption to experimental Link 16 satellite

WASHINGTON — A new Link 16-capable satellite being developed by Viasat will feature military-grade encryption, the company announced June 1.

Link 16 is the U.S. military’s primary tactical data exchange network, allowing joint war fighters to share information on the location of friendly and enemy forces to build a common operating picture of the battlefield.

But while Link 16 is of critical importance to the military in understanding the modern battlefield, it is technically limited to communications to other terminals within line of sight. In other words, it can’t be used to incorporate data from sensors and war fighters that are too far away.

The Air Force Research Laboratory wanted to change that. In 2019, the lab issued a $10 million contract to Viasat through the Space Enterprise Consortium to build a Link 16-capable satellite.

By directly tying into the Link 16 tactical network from low Earth orbit, the satellite could provide a connection node with beyond-line-of-sight forces. This space vehicle would use the vantage of orbit to connect — via Link 16 — systems that would otherwise be limited to line-of-sight communications…..

The experimental Viasat satellite will help reduce risk for the ambitious plans of the Space Development Agency, which is working to launch a new proliferated constellation made up of hundreds of satellites mostly in low Earth orbit.

That constellation will create a mesh network on orbit with optical intersatellite links (OISL) that can transport data from satellite to satellite all over the globe.

Just like with the AFRL satellite, SDA plans to outfit some of its satellites with Link 16 terminals, essentially enabling the U.S. military to push data to war fighters all over the world via the tactical network. Six of the agency’s first satellites — set to begin launching in 2022 — will be outfitted with Link 16 terminals.

Viasat initially anticipated launching the experimental satellite in summer 2020 but has pushed back the launch to fall 2021.

https://uk.pcmag.com/networking/1338...-shaped-dishes

SpaceX Tests Experimental Starlink Satellite That Uses 2 Square-Shaped Dishes

SpaceX is testing a new version of Starlink that operates via two satellite dishes instead of one.

The company revealed the experimental dish in an FCC filing last week, which was spotted by Wccftech. The document indicates the dish separates the transmitting and receiving antennas into two squares that’ll communicate with SpaceX’s satellite internet network. Each square measures 12.2 inches by 12.2 inches.

The design is notably different from the circular satellite dish design on a standard Starlink terminal, which the company has been distributing to thousands of eager customers. That dish, which measures 23 inches in diameter, contains both the transmitting and receiving antennas.

SpaceX’s application to the FCC doesn’t reveal much about the experimental dish or its purpose. The document merely says the company is seeking a six-month license to test the dish starting on July 10 in five states: California, Colorado, Utah, Texas, and Washington.

“The tests requested here are designed to demonstrate the ability to transmit to and receive information from a fixed location on the ground,” the application adds. “SpaceX will test antenna equipment functionality and analyze data link performance of the user terminal.”

The application was filed as SpaceX is rolling out Starlink across the globe to potentially millions of users in need of high-speed internet. To reach the goal, the company is trying to reduce the $499 upfront cost of each Starlink terminal, which includes the dish and a Wi-Fi modem.

The experimental dish could also represent SpaceX’s attempt to upgrade speedson the Starlink network. At the same time, the company is working to offer Starlink on moving vehicles, including boats and cars.

https://cimg5.ibsrv.net/gimg/pprune....99cbd2ef5e.png

Reference the above - breakdown on the current dish. More details in the comments below.

https://hackaday.com/2020/11/25/lite...rlink-antenna/

Tearing Apart a SpaceX Starlink Antenna

https://www.c4isrnet.com/battlefield...in-the-arctic/

NORAD, NORTHCOM want $80 million to test SpaceX and OneWeb in the Arctic

WASHINGTON — The head of U.S. Northern Command wants $80 million to continue testing SpaceX’s and OneWeb’s low Earth orbit satellite internet service, which it believes could solve the military’s Arctic communications woes.

American war fighters rely on a mix of commercial and government-owned satellites for global communications, but that infrastructure begins to run a bit thin above 65 degrees North.

Satellite availability above the 70-degree line is extremely limited, leaving U.S. forces and sensors in the Arctic with far less connectivity than the rest of the military.

But a new generation of low Earth orbit satellites designed to deliver commercial broadband could help fill that gap. Using constellations comprising hundreds of satellites, services like SpaceX’s Starlink and OneWeb are being built out to provide internet access to any location on Earth from orbit.

Last year, NORTHCOM and North American Aerospace Defense Command (NORAD) asked Congress for $130 million in their unfunded priority list — essentially a wish list of items that didn’t fit into the Pentagon’s annual budget request — to explore using those two constellations for Arctic communications. That funding enabled contract awards to SpaceX and OneWeb for full-scale testing.

Now, NORAD and NORTHCOM Commander Gen. Glen VanHerck requested $79.8 million in his FY22 unfunded priority list obtained by C4ISRNET to continue that effort — that’s about $30 million less than the commands expected to spend in FY22, according to their FY21 request.

They would use the funding to test new terminal prototypes that can connect with multiple commercial constellations, a capability laid out in the Space Force’s Fighting SATCOM Vision.

Long term, NORTHCOM suggested that this investment could encourage companies to develop more polar coverage with their communications satellite constellations.

According to the unfunded priority list, SpaceX launched 10 Starlink satellites into polar orbit in January, and plans to launch over a hundred more this summer. OneWeb told C4ISRNET in May that it had launched 182 satellites with plans to deliver Arctic coverage by the end of 2021.

That’s in line with VanHerck’s letter, where he said he expects 24/7 Arctic coverage provided by multiple commercial providers around January 2022.

The general noted that additional funding will be needed in FY23 and beyond for commercial service contracts and terminals.

https://arstechnica.com/tech-policy/...nk-satellites/

Judges reject Viasat’s plea to stop SpaceX Starlink satellite launches

SpaceX can keep launching broadband satellites despite a lawsuit filed by Viasat, a federal appeals court ruled Tuesday.

Viasat sued the Federal Communications Commission in May and asked judges for a stay that would halt SpaceX's ongoing launches of low Earth orbit (LEO) satellites that power Starlink Internet service. To get a stay, Viasat had to show that it is likely to win its lawsuit alleging that the FCC improperly approved the satellite launches.

A three-judge panel at the US Court of Appeals for the District of Columbia Circuit was not persuaded, saying in a short order that "Viasat has not satisfied the stringent requirements for a stay pending court review."

The judges did grant a motion to expedite the appeal, however, so the case should move faster than normal…….

Dish Network is also fighting SpaceX's FCC approval, and Dish's case was consolidated with Viasat's appeal. The judges set an August 6 deadline for Viasat and Dish to file opening briefs. The FCC will have until September 21, and SpaceX will have a deadline of September 28.

Dish and Viasat will have until October 12 to file replies, and final briefs are due October 26. Oral arguments will follow "on the first appropriate date" after briefs…..

The FCC has given SpaceX several approvals of satellite launches. In 2018, the FCC approved 4,408 satellites….. SpaceX also has FCC approval for another 7,500 satellites with even lower orbits…..

https://www.independent.co.uk/life-s...-b1894980.html

Spacex Applies for Licence for Ground Staion on Isle of Man for Blanket UK Broadband Coverage

There it was yesterday, in my Inbox. A note from Starlink telling me my box was on its way. After years of struggling with 1 or even sometimes a whopping 3 mbps in deepest, darkest Charente Maritime, I'm about to get some proper internet service.:ok:

:D:ok: Let us know how it goes - and whether you get the old or new dish.

NEW dish? Now I have upgrade anxiety. I wasn't aware there was an old and new...