Servicing Satellites In Orbit ?

Orionblamblam

Orionblamblam

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Arjen said:
You would need to lock the satellite in position respective to the repair-bot/-spacecraft. The last vehicle that could do just that was the Space Shuttle with its robotic arm. It made for some very costly repair missions.
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Apollo and Soyuz pulled this off prit near fitty year ago, back in the olden times (and Apollo CSM/LEM before that and Gemini/Agena before *that*). Docking a Dragon to something akin to a mass-produced lightweight Hubble does not seem all that challenging. Unless the satellite was spinning wildly out of control, rendezvous and docking would seem pretty straightforward. And if (admittedly a big IF) SpaceX pulls off their dream of launching Starships for ridiculously cheap, then docking something with a cargo bay roughly akin to the size of the Shuttles with any kind of satellite would seem almost trivial.
 
Soyuz/Apollo, ApolloCSM/LEM, Gemini/Agena all had voluminous gear for coupling. Hubble didn't have any of that, so the Shuttle's robotic arm was used. Generic coupling gear, space tugs, refuel/repair/etc in orbit would make sense, the technology is here, the problem is that the gear needed is not in place yet and will not be in place - for how many years? It would make sense to repair satellites in orbit, but right now, we can't.
I really hope SpaceX or any other company/agency will make spaceflight cheaper. I just think their LEO constellation, if realised, is too much of an obstacle to astronomy for many years to come.
 
Satellite servicing demo programs are already underway.

Again, Starlink impact on radio astronomy occurs only in the downlink transmission band shown below. Just FYI, the Hydrogen emission line which is targetted for a lot of radio astronomy is 21cm. Maybe the astronomical community could specify what in the 1.4-2.5cm band is so vital to them. I get the impression they want everyone to think the entire transmission window will be affected.

Starlink Impact.jpg
 
Robert Zubrin had chat with Elon Musk about the company's Starship rocket development facility.

Zubrin:
Musk is not building a ship, he's building a shipyard for building hundert of Starship.
SpaceX is both expanding the Boca Chica facility while also building Starship prototypes.
They have something like 300 people employed there now, in a year there will be more like 3000.
Musk want build two Starship per Week

according Zubrin calculation a Starship launch would cost $20 million and ticket seat of $300000.

more here in Podcast 90 min.

Broadcast 3459 Dr. Robert Zubrin | The Space Show

www.thespaceshow.com www.thespaceshow.com
 
Arjen said:
Soyuz/Apollo, ApolloCSM/LEM, Gemini/Agena all had voluminous gear for coupling. Hubble didn't have any of that, so the Shuttle's robotic arm was used. Generic coupling gear, space tugs, refuel/repair/etc in orbit would make sense, the technology is here, the problem is that the gear needed is not in place yet and will not be in place - for how many years?
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Pretty sure that as space telescopes go into series production, the attachment features will be designed and built along with it. Harldy seems like they *wouldn't* go together.
 
If the LEO constellations go up, it will likely take a couple of years for the whole fleet to reach orbit. There will be a gap between the full deployment of Starlink and deployment of astronomical satellites with the attending service infrastructure, the length of that gap (years? decades?) depending on funding and launching capacity. During Starlink's deployment, ground based astronomy will become less and less effective - destruction of scientific capital. I know proof-of-concept work on in-orbit servicing is going on, but I do not want to hold my breath for the time that is needed for it to become practical.
 
Then there is the minor matter of who is going to pay for it all. Kessler syndrome affecting space telescopes?
 
Arjen said:
Then there is the minor matter of who is going to pay for it all. Kessler syndrome affecting space telescopes?
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Who is going to pay to shut down all the house, street and car lights in the metropolis I currently find myself in so's I can have a nice dark night sky again?
 
Who is going to pay for the space telescopes? Launching might eventually be cheaper, the space telescopes will still be very costly. Especially if they are to replace the extensive ground based observatories that have already been driven to the remote places where dark skies can yet be found. You will not find many of those around where you live.
 
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Arjen said:
... the remote places where dark skies can still be found. You will not find many of those around where you live.
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But you have previously linked to an argument that a dark night sky is basically a human right. Since city lights are far more damaging to that sort of thing than a few rinkydink satellites, *CLEARLY* the higher priority is for urban areas to reach North Korean levels of nighttime dark-lightenment. What's your plan on achieving that? This comes *before* the piddling notion of figuring out who pays for the space telescopes. Remember:
The right to see the sky in natural state belongs to our rights and freedoms alikethe right to breath unpolluted air, drink clean water or sleep in a quiet environment during the night.

Perhaps the approach that would make everyone happy is to use SpaceX launchers to orbit a bajillion satellites based on Starlink... satellites that keep an eye on the night side of Earth and launch small kinetic-kill warheads towards detectable artificial lights at night. Or Starlink-sats each equipped with nuclear devices in the low kiloton range, tinkered to be just perfect for EMP generation to take out night-time power grids. Soon the night will be dark again.
 
Piddling argument of funding - piddling only applies if you are spending other people's money.
 
Arjen said:
Piddling argument of funding - piddling only applies if you are spending other people's money.
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If we are back to optical telescopes (instead of radio), we once again must realize that these satellites are only visible during dawn/dusk. Like the Starlink emission band occupying a small fraction of the radio astronomy band, this time period is a small fraction of the optical observing period. It might even qualify as "piddling".
 
In matters of what ground based astronomy can and cannot do and in what is likely to affect ground based astronomy I would say astronomers are a knowledgeable lot. They are the everyday users of all that gear, and they are worried. I again refer to the three Italian astronomers' document -
and the IAU's statement -
www.iau.org

International Astronomical Union | IAU

www.iau.org www.iau.org

The word 'piddling' is conspicuously missing from both.
 
That, alas, would be impractical. Whereas moving observatories to remote locations was, and has been done at great cost. Now astronomy is looking at another very costly move with the possibility of being hobbled for an indeterminate period of time. Even if the money can be found.
 
Arjen said:
In matters of what ground based astronomy can and cannot do and in what is likely to affect ground based astronomy I would say astronomers are a knowledgeable lot. They are the everyday users of all that gear, and they are worried. I again refer to the three Italian astronomers' document -
and the IAU's statement -
www.iau.org

International Astronomical Union | IAU

www.iau.org www.iau.org

The word 'piddling' is conspicuously missing from both.
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Who introduced the "piddling" meme? Looking at the above posts it seems you did.

As with all things, I look at the base facts and do my own thinking. I don't outsource my judgement. The graph of the radio band and the time period of dusk/dawn relative to astronomical observing periods can be examined directly by yourself.
 
The arguments, though well constructed and present both positions well, have become circular. What will rule the day is the 'greater good'. Internet access and speed is wanted by more people than those people who want to star-gaze at ground level. Don't panic guys, the stars ain't going anywhere between now and when we start looking at them through a hard vacuum.
 
Arjen said:
That, alas, would be impractical. Whereas moving observatories to remote locations was, and has been done at great cost. Now astronomy is looking at another very costly move with the possibility of being hobbled for an indeterminate period of time. Even if the money can be found.
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Leaving hundreds of millions of peoples without access to world web would also be impractical, you know.
 
OBB introduced piddling, I thought it inappropriate. Outsourcing judgement - my judgement is not formed in a vacuum, I can not escape weighing opinions and evidence. My choices are different from yours.

There are other ways to provide internet connections than Starlink.

We have been here before, the argument, as Merriman writes, has become circular.
 
Arjen said:
OBB introduced piddling, I thought it inappropriate. Outsourcing judgement - my judgement is not formed in a vacuum, I can not escape weighing opinions and evidence. My choices are different from yours.

There are other ways to provide internet connections than Starlink.

We have been here before, the argument, as Merriman writes, has become circular.
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Or as in many threads, political in its fundamental disagreement. Which of course means resolution never arrives until the topic moves into a stage where it becomes moot.
 
Arjen said:
my judgement is not formed in a vacuum
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Perhaps not. But with the help of SpaceX or a firm like them, your judgement can be *sent* to a vacuum where it will have a clear, nearly 24/7 view of the stars, without all the bother of atmospheric seeing, clouds, birds, bugs, city lights, airplanes or even satellites. And vacuum judginess is best judginess.
 
Arjen said:
There are other ways to provide internet connections than Starlink.
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As there are ways to look at the sky... Building infrastructure to the ends of the earth is just as expensive as building space telescopes. Probably a good deal more so.
 
Arjen said:
Who is going to pay for the space telescopes? Launching might eventually be cheaper, the space telescopes will still be very costly. Especially if they are to replace the extensive ground based observatories that have already been driven to the remote places where dark skies can yet be found. You will not find many of those around where you live.
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Who's going to pay for my electric car when fossil fuels are banned?
 
The Atacama Large Millimeter Array, the most expensive ground based observatory so far, costs in the order of 1 - to 1.5 billion dollars. In the run up to building the James Webb Space Telescope, 'low cost' space telescopes were proposed at half a billion a piece. Hubble cost went past the Atacama Array by a billion or so, on the construction of JWST alone over 5 billion had been spent.
 
Arjen said:
The Atacama Large Millimeter Array, the most expensive ground based observatory so far, costs in the order of 1 - to 1.5 billion dollars. In the run up to building the James Webb Space Telescope, 'low cost' space telescopes were proposed at half a billion a piece. Hubble cost went past the Atacama Array by a billion or so, on the construction of JWST alone over 5 billion had been spent.
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So, you're suggesting that by financially supporting SpaceX by allowing them to launch as many Starlinks as they want will incentivize reduced launch cost, in turn rapdily and importantly dropping the cost of design, construction, launch and maintenance of space telescopes. Well done!
 
Not at all. Space telescopes are very expensive pieces of kit, irrespective of launching costs.
 
Arjen said:
Not at all. Space telescopes are very expensive pieces of kit, irrespective of launching costs.
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The cost of satellites is coming down. Used to be you'd need a $ 1billion+ KH-11 to look at things on the ground. Not so anymore. One wonders what could be accomplished with an array of cubesats combined into one telescope.
 
A nice idea for the future, but when will that be operational? With what kind of results? We have been here before.
 
To repeat Hyman Rickover "It is a human inclination to hope things will work out, despite evidence or doubt to the contrary. A successful manager must resist this temptation"
 
Arjen said:
To repeat Hyman Rickover "It is a human inclination to hope things will work out, despite evidence or doubt to the contrary. A successful manager must resist this temptation"
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This isn't one of those things. Large satellite constellations are going to happen. That's a fact. What remains to be discovered is how it will impact astronomy.
 
Astronomers, who appear to be most qualified to judge the matter, are deeply worried.
 
Arjen said:
Astronomers, who appear to be most qualified to judge the matter, are deeply worried.
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They are deeply worried that the economies of scale will make space launch simpler, easier and cheaper, and fill the sky and the surface of the moon with far better telescopes and render their terrestrial scopes obsolete?

Nobody today much worries about the ferry boats being rendered obsolete by railroad bridges.
 
Here is a company selling a device for helping de-orbit low orbiting satellites after their useful lifespan is up. They were funded through a USAF small business R&D program.

"Dragnet"


They specialize in deployable structures. Here is a high gain antenna. I'd like to see one that creates a giant Origami Crane when it unfurls.
 

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