A New Satellite Outshines Some of the Brightest Stars in the Sky (nytimes.com) 41
Becky Ferreira writes via the New York Times: Last November, a satellite in low-Earth orbit unfurled into an expansive array that extends across nearly 700 square feet, about the size of a studio apartment. The satellite, BlueWalker 3, has since become one of the brightest objects in the sky, outshining some of the most radiant stars in the Milky Way, according to a study published on Monday in Nature -- and it is just the first of dozens of similar satellites that are in development by AST SpaceMobile, a company that aims to keep smartphones connected from orbit. "The issue is not necessarily that one satellite," said Siegfried Eggl, an astrophysicist at the University of Illinois, Urbana-Champaign and an author of the new study, "but that it is a predecessor or prototype of a constellation, so there's going to be a lot of those out there eventually."
Initially launched in September 2022, BlueWalker 3 is the forerunner of AST SpaceMobile's BlueBird satellites, which aim to serve as a network of orbital cell towers with the goal "to democratize access to knowledge and information regardless of where people live and work," a spokesperson for AST SpaceMobile said. Last month, BlueWalker 3 successfully relayed its first 5G connection to a smartphone in a cellular coverage gap on Earth. AST SpaceMobile is one of many companies racing to capture the surging demand for global broadband connectivity. "At the moment, there are 18 constellations that we know are planned all over the world," Dr. Eggl said. "The total number of satellites is a stunning half a million that people are planning to put up there. This is 100 times more than we already have."
AST SpaceMobile made BlueWalker 3's array so large in order to beam strong cellular coverage directly to phones on Earth. The satellite is made of many small antennas that can connect existing smartphones, which is an approach that distinguishes the company from Starlink and other planned constellations that currently rely on ground antennas or dishes. [...] AST SpaceMobile said that it was working with astronomers on techniques to reduce disruptions. It also contrasted the number in its constellation with the tens of thousands planned by other companies. The spokesperson said it could "provide substantial global coverage with around 90 satellites." Though BlueBird satellites would be far fewer in number, they are at least 64 times as big and bright as a Starlink satellite. The SpaceX orbiters are also brightest in the days after their deployment, but they become much fainter once they settle into their target orbits. Astronomers expect that the BlueBird satellites will remain bright in the sky throughout most of their lifetime. As a consequence, one of these satellites could interfere with data captured by astronomical observatories.
Initially launched in September 2022, BlueWalker 3 is the forerunner of AST SpaceMobile's BlueBird satellites, which aim to serve as a network of orbital cell towers with the goal "to democratize access to knowledge and information regardless of where people live and work," a spokesperson for AST SpaceMobile said. Last month, BlueWalker 3 successfully relayed its first 5G connection to a smartphone in a cellular coverage gap on Earth. AST SpaceMobile is one of many companies racing to capture the surging demand for global broadband connectivity. "At the moment, there are 18 constellations that we know are planned all over the world," Dr. Eggl said. "The total number of satellites is a stunning half a million that people are planning to put up there. This is 100 times more than we already have."
AST SpaceMobile made BlueWalker 3's array so large in order to beam strong cellular coverage directly to phones on Earth. The satellite is made of many small antennas that can connect existing smartphones, which is an approach that distinguishes the company from Starlink and other planned constellations that currently rely on ground antennas or dishes. [...] AST SpaceMobile said that it was working with astronomers on techniques to reduce disruptions. It also contrasted the number in its constellation with the tens of thousands planned by other companies. The spokesperson said it could "provide substantial global coverage with around 90 satellites." Though BlueBird satellites would be far fewer in number, they are at least 64 times as big and bright as a Starlink satellite. The SpaceX orbiters are also brightest in the days after their deployment, but they become much fainter once they settle into their target orbits. Astronomers expect that the BlueBird satellites will remain bright in the sky throughout most of their lifetime. As a consequence, one of these satellites could interfere with data captured by astronomical observatories.
This is just the beginning (Score:5, Interesting)
Re: This is just the beginning (Score:2)
Yeh, I really think astronomers are underestimating the power of these constellations for them. They should really be going âoeohhh, itâ(TM)s now relatively cheep to put thousands of telescopes in orbitâ rather than worrying about them. Theyâ(TM)re still stuck in the mindset of âoespace telescopes are expensive single things that you spend decades developingâ rather than âoeFalcon 9 can launch these so fast that we can build many more cheeper ones and get vast troves of
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It is much harder to service a telescope in space. Maintenance matters.
Re: This is just the beginning (Score:2)
Not when thereâ(TM)s 10,000 of them, and you can launch another 100 of them trivially.
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A decent telescope needs a decent mirror. A good mirror is a) expensive and b) heavy relative to everything else. Technology makes that easier, but look at how complex and difficult the web telescope was to deploy and you will begin to see the problem.
If you have a great technical solution to this that actually works in real life then great, but you'll have to demonstrate it before people are happy and that hasn't happened yet.
Re: This is just the beginning (Score:4, Insightful)
James Webb's 18 segments are only 20kg each. The launch cost per segment is only $30k at SpaceX Falcon-9 prices (much cheaper with Starship). "Mirror launch costs" are a non-issue. Feel free to make them much heavier if it reduces production costs. Back them with cast iron if you want.
James Webb was complicated to deploy because it was huge, complex, unique, and had to unfold like origami. Literally none of that is what's being described here. What's being described here is small telescopes (optical and radio) which only need to unfurl solar cells (not even remotely immature technology today) and are mass-produced, which a unit cost so low that you can easily afford to lose some, so there's no need to get everything perfect off the bat. These are then used together for interferometry, to get insane angular resolutions - as well as not having to deal with atmospheric distortion or manmade interference.
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Also, it isn't real astronomists that are likely complaining, but amateur / education based astronomy which doesnt have the full funding of NASA or governments. Those guys are only more excited to see our capabilities expand.
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These are then used together for interferometry, to get insane angular resolutions - as well as not having to deal with atmospheric distortion or manmade interference.
How do you plan to do interferometry between multiple separate satellites in orbit?
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N.B. The question applies to optical, or even infrared wavelengths. I can believe in that being done at radio wavelengths.
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Tom Scott did a video of visual interferometry and they are using delay lines to use analog interference.
Apparently we don't have computers fast enough or clocks accurate enough to do it digiitaly.
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Tom Scott did a video of visual interferometry and they are using delay lines to use analog interference.
Apparently we don't have computers fast enough or clocks accurate enough to do it digiitaly.
Yeah, which means that the entire suggestion of doing it in space is impossible as I understand it. Perhaps if they physically connected together? Anyway, modding it up to 4 when it's impossible is, uh, interesting.
Re: This is just the beginning (Score:2)
A decent telescope mirror is *really* easy to make when
1. Theyâ(TM)re not very large
2. Youâ(TM)re producing thousands of them
The reason webâ(TM)s mirror was so expensive was because it was a *single* mirror that had to be so optically perfect that even a relatively small (yes, itâ(TM)s big for a satellite, but itâ(TM)s still a relatively small mirror) could collect enough light accurately enough to be useful. When you replace that with mirrors maybe 1 meter across, producing them g
Not a Good Choice (Score:3)
The gotcha is that optical light interferometry is hard
Yes, extremely hard requiring extremely precise length adjustments at the 10's of nanometre precision scale. There is no way we can do it in orbit at the moment given how challenging it is to do on Earth. We may eventually be able to do it like we do for radio but that will need technology well beyond what we are capable of today.
Plans to replace major terrestrial telescopes with clusters of "cheap" space telescopes are fiction, not science, with today's technology. Yes, we probably will eventually be a
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It is more like allowing the people who are remote access to the internet not just for social media.
But yes we can not do optical light interferometry in orbit.
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Disco Spaceballs (Score:3)
Back in the day we used to have pirates launch a fleet of disco balls into space to have a nice and glittery sky.
https://www.eoportal.org/satel... [eoportal.org]
If we launch a collection of thousands and thousands of disco balls today, we would dance all over earth, watching at all those Disco Spaceballs.
Try to top that, Elon :) (Score:3)
And the badass pirates used child labor to make the satellites. :)
Giving a giant middle finger to astronomers trying to see faint light
Try to top that, Elon
Re:This is just the beginning (Score:5, Insightful)
But, the boon to astronomy will also get better. Telescopes like the Hubble and JWST are much better than in-atmosphere earth-based observatories
All you said is true, but if you are an amateur astronomer or not in the first tier of professional astronomers, how will you get access to telescopes like Hubble ? These satellites may become a career ending for many astronomers.
If you search, many discoveries, even very recently, were first found by amateurs. That is because budgets are not large enough to look for everything out there.
Plus Radio astronomy is not even mentioned, that is already being hurt by many satellites already up there.
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In reality its inevitable - space based communications are just too valuable to gi
700 sq ft studio?! (Score:4, Informative)
That's a big studio apartment! Around here, 700 sq ft (65 m^2) will get you a decently sized two bedroom apartment with the kitchen in its own room.
I think that's big for a studio anywhere (Score:2)
I own a 30 square metre studio apartment (in addition to the 2 bedroom apartment I rent), and that's already considered big, with the (tiny) kitchen in a separate room, and another separate room for the toilet, shower, basin and washing machine. A 65 square metre apartment would be more than twice as big again.
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Thanks to Apple's trillions (Score:3)
I don't really have a problem with it, but for those who do ... don't forget, these specific ones are there because Apple is picking up the tab :p
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What's the "tab" for arrogating for yourself the view of the night sky that is the heritage of every human on the planet?
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Honestly, being able to visually spot, identify, and track a satellite as it goes over my back garden enhances, rather than diminishes, the star watching experience.
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Agreed.
The kids love it too.
Imagine what an uncontacted tribe must think when a -3.7 ISS goes overhead!
Oh, a socialist satellite (Score:2)
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Well, that's OK then.
And it's GREEN too! Cuz it is solar powered!
I have gone out to see this thing (Score:2)
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Well, to be fair 4.5 magnitude is probably brighter than almost every other star in the universe from our point of view ;)
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Like any satellite it will be brightest right after sundown or right before sunrise, while it is in the sun but you are not.
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Thanks. I go outside for an ISS pass of -2.5 or better.
Many good ones lately!
700 sqft studio apartment? (Score:2)
Where is this at? My one bedroom is only 580 sqft...
Uncoordinated and they don't care. (Score:2)
This satellite was launched without regard for frequency coordination, and are transmitting illegally.
It's so bad, satnogs has a separate monitoring program for the emissions.
https://db.satnogs.org/satelli... [satnogs.org]
"Democratize"? (Score:2)
I tend to immediately suspect any business entity that tries to claim that their product or service is there to 'democratize'. No. It's there to make money, either by taking marketshare from existing operations, or to expand the market itself by either offering something that people will learn about and then desire, or by bringing down costs to where more customers can afford it.
There's nothing democratic about business.
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You left out the number one definition of "democratize" - dump external costs and penalties on others. Have everyone inconvenienced, harmed and picking u the bill is democracy at its greatest!