Starlink and the future of communication at sea

[GordMay]

SpaceX satellites are leaking radio waves

Researchers [1] turned a radio telescope towards 68 of SpaceX’s Starlink broadband satellites, and found that 47 of them were emitting radio waves, at frequencies in a protected band [between 110 and 188 MHz], allocated to radio astronomy, by the ITU.
Gadgets on the ground, that emit these frequencies, are regulated by strict rules; but they don’t apply in space.
There are now more than 4,300 satellites in the Starlink system, and astronomers are concerned that huge ‘megaconstallations’ of the objects could, one day, cause problems for observation.

More about ➥ https://cps.iau.org/news/new-radio-a...onstellations/

[1] “Unintended electromagnetic radiation from Starlink satellites detected with LOFAR between 110 and 188 MHz” ~ by F. Di Vruno et al
➥ https://www.aanda.org/articles/aa/pd...aa46374-23.pdf

[GordMay]

Four astronauts, from four countries [NASA's Jasmin Moghbeli USA, European Space Agency's Andreas Mogensen Denmark, Japan's Satoshi Furukawa, & Russia's Konstantin Borisov] launched, from Kennedy Space Center, toward the International Space Station, on Saturday [yesterday].
They should reach the orbiting lab, in their SpaceX capsule, Sunday [today, Aug 27], replacing four astronauts living up there, since March.
SpaceX has now launched eight crews, for NASA.
Another NASA astronaut will launch to the station, from Kazakhstan, in mid-September , under a barter agreement, along with two Russians.

By 2030, satellites could outnumber visible stars by 30:1.

A casual glance into the night sky, on a clear night, reveals between 2,000 and 2,500 stars, giving us a view 16,000 lightyears away, and into our past.
But, There are only 172 stars, in the whole sky, exceeding the expected brightness of Starlink satellites.

The Union of Concerned Scientists, which keeps a record of operational satellites, said that, as of January 2021, there were 6,542 satellites in Earth orbit.[1] Of that total, 3,372 are active, and 3,170 are inactive.

Various companies are now sending thousands of satellites skyward. They’re connecting the satellites into what are called constellations, which are groups of satellites working together as a single system. The best known planned mega-constellation of satellites is SpaceX’s Starlink. There’s also OneWeb, Amazon’s Kuiper and China’s StarNet/GW.
Together, they’re currently planning to launch a total of 65,000 satellites.[2]

A team of scientists created a new simulation, of the potential positions, and brightnesses of these satellites. They submitted their study [2], to the American Astronomical Society journals, for review. A preprint, dated September 14, 2021, is available online.[2]

Because these 65,000 satellites are so much closer to us, we’d see these “artificial stars” move. And movement draws the eye. So, on a dark night, when you looked up, your eye would be drawn to the satellites, more than the stars.

Satellites shine by reflecting the sun’s light. For this reason, they’re usually only visible during the beginning of night, and as morning approaches, when the sun’s rays can still reach them, high above Earth. But at latitudes, such as 50 degrees north and south, locals will see satellites all night long, near the summer solstice, and near sunrise and sunset, on the equinoxes.

The additional satellites increase the danger of the Kessler syndrome [3]. The Kessler syndrome [3] theorizes that eventually, as low Earth orbit gets crowded with satellites, collisions could cause a cascading effect, with debris from one collision triggering further collisions, until this area of space, where most satellites operate, could be rendered useless.

Could this affect astro’ navigation, or, even, GPS nav’ [Kessler]?

More about: “Astronomers have serious concerns about satellite constellations”
➥ https://phys.org/news/2020-02-astron...ellations.html

[1] “How many satellites are orbiting the Earth in 2021?”
➥ https://www.geospatialworld.net/blog...earth-in-2021/

[2] “Visibility Predictions for Near-Future Satellite Megaconstellations: Latitudes near 50 Degrees will Experience the Worst Light Pollution” ~ by S. M. Lawler, A. C. Boley, & H. Rein
➥ https://arxiv.org/abs/2109.04328

”... Here we provide predictions for the optical brightnesses and on-sky distributions of several satcons, including Starlink, OneWeb, Kuiper, and StarNet/GW, for a total of 65,000 satellites on their filed or predicted orbits...”

[3] “Kessler syndrome” ➥ https://en.wikipedia.org/wiki/Kessler_syndrome

[catalystcat]

Not to move back toward the original topic too much, but KVH and Eutelsat One Web have announced a partnership
https://www.rivieramm.com/news-conte...ectivity-79180
They will do a hybrid GEO/LEO system. "“LEO technology will complement, enhance and extend our network’s existing hybrid services and enable low-latency connectivity for mariners worldwide.”
One Web may not be a household name everywhere, but they do have 630 satellites up and this system also provides access to Intelsats GEO constellation.
Very curious to see how they position this pricewise and servicewise.
( I do know that the antenna performance they can get with the Kymeta metamaterials technology can do better than the Starlink's steerable aperture for a given aperture size. )

[GordMay]

On April 2 [at 1:40 AM], an explosion was seen in the California sky.
While some assumed the fiery display was from a Space X rocket, that launched just hours prior, aerospace researchers claim the object was actually the orbital module, of the Shenzhou-15 rocket, that China launched nearly a year and a half ago.

On Nov. 29, 2022, China's Shenzhou-15 rocket blasted off, with three astronauts on board.
The rocket was made up of multiple modules, and the one carrying the astronauts landed safely*, in China, in June 2023.
Evidently, the 3,300-pound orbital module, that exploded over Los Angeles, was not designed to safely reenter Earth's atmosphere.
Debris has not been discovered in California, but it's believed that the space junk, either burnt out, in the upper atmosphere. or landed in the Pacific Ocean.

* Pilot Zhang Lu receives assistance, as he makes his way out of the Shenzhou-15's return capsule, at Dongfeng Landing Site, in Inner Mongolia, on June 4, 2023. ➘

[GordMay]

SPACE JUNK:

There are thousands of satellites, and millions of pieces of space debris, in orbit around Earth.

New studies [1 a & b] suggest that more research needs to be done, to find out how they may be affecting our atmosphere, when they burn up.

A variety of vapourized metals [20 different particulates, like lithium, aluminum, niobium, and hafnium], in the stratosphere, linked to satellites, could potentially affect our ozone layer.
These metals were found in roughly 10 per cent of sulphuric acid particles, which make up a large part of our atmosphere.

There are an estimated 11,500 tonnes of space objects, orbiting Earth, which would include even the smallest pieces, around one millimetre in size.

But, there are far larger objects in space, including spent rocket stages, and upwards of 9,000 functioning satellites. More than half of them are SpaceX Starlinks, which provide internet services.
Currently, there are roughly 5,200 Starlink satellites, but SpaceX has plans to put up upwards of 42,000. These satellites have a lifespan of roughly five years, after which they're deorbited. They, then, burn up, in our atmosphere.

Roughly 30 kilograms of aluminum oxides are produced, by the burning of a 250-kilogram satellite.
In 2022, 17 tonnes of aluminum oxide nanoparticles were released into the atmosphere, from satellites.
And, this was before Starlink satellites began to deorbit, which only started earlier this year.

Looking at the potential of megaconstellations, the scientists [1b] estimated that 360 tonnes of aluminum oxide particles could be released, annually - a 646 per cent increase, above natural atmospheric levels.

[1a] “Potential Ozone Depletion From Satellite Demise During Atmospheric Reentry in the Era of Mega-Constellations” ~ by José P. Ferreira et al
➥ https://agupubs.onlinelibrary.wiley....9/2024GL109280

[1b] “Metals from spacecraft reentry in stratospheric aerosol particles” ~ by Daniel M. Murphy et al
➥ https://www.pnas.org/doi/10.1073/pnas.2313374120


See also:

Space Environment Statistics ➥ https://sdup.esoc.esa.int/discosweb/statistics/

Starlink Statistics ➥ https://planet4589.org/space/con/star/stats.html

[GordMay]

Russia began to disrupt Sweden's [Sirius] satellite networks, on March 21, just two weeks after the Scandinavian country became a NATO member, according to a letter [to the International Telecommunications Union, ITU], from the Swedish Post and Telecom Authority [PTS].

More about:
“Sweden Says Russia Disrupting Its Satellite Networks”
➥ https://www.swissinfo.ch/eng/newest-...works/81257029

[catalystcat]

Interestingly, there have been companies getting funded to deal with space debris over the past couple of decades or so. Publications go way back. e.g., https://www.esa.int/esapub/bulletin/...r16_bul109.pdf

WRT fixing the problem here is just one of a bunch of articles describing some of the startups whose pitches were about making money by dealing with debris. https://www.startus-insights.com/inn...pace-industry/

There are people who believe that dealing with space garbage, doing space-based maintenance, and other space-based services (e.g., local power delivery, deviation tracking, etc.) will be a reasonably large business area in a few years. https://www.cnbc.com/2023/08/24/inve...is-market.html

Astroscale was recently valued at a $1B. https://asia.nikkei.com/Business/Mar...n-market-debut

[toddster8]

A few decades ago (!) I was collaborating with some folks at NASA and was taken on a tour of their microanalysis lab. One of the projects was analyzing all the micrometeorite impacts on spacecraft surfaces. Even back then, they were finding that the majority of impacts were from particles of titanium paint that flaked off other spacecraft. IIRC.