Launching Starlink with Starship

[su27k]

Does satellite re-entry have a real significant impact? I've spend a some minutes googling and most of what I found is relatively fuzzy statements which indicate that burning large amounts of aluminium is "not well studied" but no quantitative measures of negative impact.

You're right, it's not well studied and so far all the negative impacts are just hypothesis. But this is almost worse than a real, scientifically proven impact, since a hypothesis leaves infinite room for creating FUD, the impact can be exaggerated to as big as you want. And the enemies of SpaceX would just love to stop Starlink launches so that "scientists can have time to study the effect", which of course will take decades.

I know that lawsuits were files for this exact purpose but it seems extremely unlikely that they will win. Historically the US has not embraced the precautionary approach to regulation and seems unlikely to start now in an area with defense implications.

Europe takes a different approach and it can be seen in areas like fracking and GMO crops but this is unlikely to impact Starlink. After all, SpaceX is an US company.

Yeah, I'm not too worried about the current lawsuit. But that is just for the 2,000 or so current generation Starlink, which were already approved by FCC years ago. My suggestion is more for the 30,000 more later generation Starlink satellites waiting for approval by FCC, you can bet this environmental argument is not going away just because Viasat lost the case.

[groundbound]

Just thought about this today: Once SpaceX starts launching Starlink using Starship, they could also recover the old Starlink satellites and bring them back to Earth instead of burning them up in the atmosphere. They can do this since the new satellites will need to be launched into the same orbit as the old satellites, so if you're replacing old satellites, the ship is in an ideal position to retrieve the old satellites, store them in the empty cargo bay vacated by the new satellites and land them on Earth.

Why would they want to do this? Two birds with one stone:

I can't understand why this would even seem desirable.

They aren't in the same orbit.  They are in the same plane.  Those a vastly different things and it makes the retrieval of even two satellites at once immensely harder.

I can't begin to imagine an automated way to properly stow a host of Starlinks.

I don't see why in the world you would say this; when the Starship gets to the first Starlink, most of the rest of them are a mere few thousand miles away. Heck, one starship should be able to manage to match orbits with the rest of that plane in only a year or two.

And its not like there is any possible use for that Starship in the mean time....

[su27k]

Just thought about this today: Once SpaceX starts launching Starlink using Starship, they could also recover the old Starlink satellites and bring them back to Earth instead of burning them up in the atmosphere. They can do this since the new satellites will need to be launched into the same orbit as the old satellites, so if you're replacing old satellites, the ship is in an ideal position to retrieve the old satellites, store them in the empty cargo bay vacated by the new satellites and land them on Earth.

Why would they want to do this? Two birds with one stone:

I can't understand why this would even seem desirable.

They aren't in the same orbit.  They are in the same plane.  Those a vastly different things and it makes the retrieval of even two satellites at once immensely harder.

I can't begin to imagine an automated way to properly stow a host of Starlinks.

I don't see why in the world you would say this; when the Starship gets to the first Starlink, most of the rest of them are a mere few thousand miles away. Heck, one starship should be able to manage to match orbits with the rest of that plane in only a year or two.

And its not like there is any possible use for that Starship in the mean time....

I assume you're being sarcastic.

But this is not a showstopper, the way you avoid having to chase down the rest of the satellites is to let the satellites themselves gather up in one location, they do have their own propulsion you know? And very efficient one at that. Essentially you just do the reverse of the initial deployment process, and gather all the old satellites in a new train near the orbit Starship is going to deploy the new satellites, this way Starship can pick them up one by one quickly.

[rsdavis9]

I assume you're being sarcastic.

But this is not a showstopper, the way you avoid having to chase down the rest of the satellites is to let the satellites themselves gather up in one location, they do have their own propulsion you know? And very efficient one at that. Essentially you just do the reverse of the initial deployment process, and gather all the old satellites in a new train near the orbit Starship is going to deploy the new satellites, this way Starship can pick them up one by one quickly.

On top of that a small OTV with a big net could gather them very efficiently if they were all bunched up and moving with the same velocity. Then starship just has to catch the whole load, OTV and net.

[DreamyPickle]

Starlinks are very tightly packed on launch. It would be next to impossible to gather a similar amount using propulsive maneuvers so this would only return a fraction of the satellites that go up every launch.

If the satellites move around inside the payload area during descent they are very likely to mess up the center of gravity or damage the steel hull.

This is a very difficult and inefficient solution for an entirely hypothetical problem.

[AC in NC]

gather all the old satellites in a new train near the orbit Starship is going to deploy the new satellites, this way Starship can pick them up one by one quickly.

How?  You can't handwave around this part.

The scenario is nonsensical.  You have either (A) non-functional or (B) end-of-life satellites withed deploy solar panels.  In both cases they are essentially worthless. 

You expect these all to be marshalled to some rendezvous point, have them de-deploy their solar panels, and be captured by some mechanism and safely stowed inside SS in some kind of secure fixture?  It's ludicrous.  There's a reason they were designed to be fully demisable. It's because the only fate any of these satellites will ever have is a fiery burn to nothingness.

[meekGee]

They might grow a little in size, but I expect they will for the most part just add more satellites for more capacity. Having a greater number of satellites allows for better coverage, where you can see a smaller and smaller part of the sky and still have good coverage.

The number of satellites is generally a function of altitude. For any observer, figure on 2-3 satellites in the useful sky dome (30 degrees above horizon) in each direction at any given time (so 4-9 within useful line of sight)

So suppose they're at 500 km.
120 degrees arc is 1000 km long.
So the satellites are 500 km apart.
So a meridian circle has 40000/500=80 satellites.
Very roughy 80*80=6400 satellites.

Same exercise for 1000 km yields about 1600 satellites.

Same exercise for 350 km yields 14,000 satellites.

Very rough, but it's fundamentally a square power relationship, and of course depends a lot on the actual shell parameters.

I don't think you'd want more sats in the field of view.  So my vote is that they'll get larger.

This is also btw why it's such a small impact on astronomy. 4-9 within line of sight, and only a minority lit, and only some of the time.

[su27k]

gather all the old satellites in a new train near the orbit Starship is going to deploy the new satellites, this way Starship can pick them up one by one quickly.

How?  You can't handwave around this part.

The scenario is nonsensical.  You have either (A) non-functional or (B) end-of-life satellites withed deploy solar panels.  In both cases they are essentially worthless. 

You expect these all to be marshalled to some rendezvous point, have them de-deploy their solar panels, and be captured by some mechanism and safely stowed inside SS in some kind of secure fixture?  It's ludicrous.  There's a reason they were designed to be fully demisable. It's because the only fate any of these satellites will ever have is a fiery burn to nothingness.

The exact design would depends on a lot on the new satellite design and new deployment mechanism, I'm not going to 2nd guess SpaceX on that (who predicted they went with a flat pack with no deployer for 1st generation Starlink?).

For this idea to be practical, I just need to show a. it's doable and b. SpaceX is going to develop it. It's not necessary to predict the exact design:

1. Retrieve satellite and store it securely inside payload bay: Already demonstrated by Shuttle nearly 40 years ago, this is TRL9 technology. And SpaceX will be developing this technology, since this capability is specifically mentioned in the Starship User Guide: "With a fully reusable Starship, satellites can be captured and repaired in orbit, returned to Earth, or transferred to a new operational orbit."

2. Retractable solar array: ROSA is designed to be retractable, although it didn't work when they tried it. So not exactly TRL9 but close. And SpaceX will also be developing this technology, since they needed it for the Mars Starship.

BTW, Starlink satellites are not supposed to be used up and non-functional when they dispose of it, this is not GEO we're talking about where you use the satellite until it died on you. Starlink satellites are supposed to be like your cellphone or servers in a data center, they got replaced not because they no longer work but because there're much better model available.

And as a practical matter, even for the current generation Starlink, SpaceX need to keep the disposed satellite maneuverable until they re-enter the atmosphere, this is required since it needs to do collision avoidance all the way down, the last thing you want is hundreds of out of control satellites running around low LEO.

[AC in NC]

For this idea to be practical, I just need to show a. it's doable and b. SpaceX is going to develop it. It's not necessary to predict the exact design.

Neither (a) or (b) has anything to do with practicality in the case of retrieving Starlinks.

No.  What you have to show is that there's an economic case to do so.  That economic case involves not handwaving around how you are going to do a retrieval (either automated or via the most complex EVA(s) in history either of which must be compatibly co-located with the systems necessary to deploy the new Starlinks since the only way you are justifying this is by degrading the network to marshall the to-be-replaced Starlinks to a rally point and retrieving them in the same mission that just deployed new ones).  That is very much different than your TRL9 Shuttle example.  And it involves what value there is in retrieving a Starlink that is ready to be replaced.  And it involves the cost of refining your Starlinks to include all the features that make such a retrieval possible.

Too much handwaving.  There's no economic case to do all that. 

If you think otherwise, sketch it out rather than just declaring that it's practical because single satellites have been retrieved in the past, because retractable technology exists somewhere, and that Starlinks aren't non-functional when they are no longer worth leaving in orbit.

[su27k]

For this idea to be practical, I just need to show a. it's doable and b. SpaceX is going to develop it. It's not necessary to predict the exact design.

Neither (a) or (b) has anything to do with practicality in the case of retrieving Starlinks.

No.  What you have to show is that there's an economic case to do so.

I'm confused, I laid out the reasons why SpaceX might want to do this in my initial post here, I'm not arguing there is an "economic case", this is not an attempt to reduce the cost.

Not everything SpaceX did with Starlink is to reduce the cost, for example:

1. There's no economic case to make the current generation fully demisable, their original design is not fully demisable, they need additional engineering and had to change out some components to make it fully demisable. And legally they're not required to do this, legally each satellite is allowed to cause 1 in 10,000 probability of casualty on the ground. But it turns out if you have 12,000 satellites, then the aggregated probability of killing somebody on the ground is 45%. So SpaceX changed the plan and made the satellite fully demisable, there's no "economic case" for doing this, they're doing this for non-economic reasons.

2. Same thing for reducing the brightness of Starlink satellites, they didn't have to do this, there's no law that says they must do this, and certainly there's no "economic case" to do this. But they're devoting considerable engineering effort ("An entire team/department" as an astronomer put it) to mitigate this issue.

[AC in NC]

For this idea to be practical, I just need to show a. it's doable and b. SpaceX is going to develop it. It's not necessary to predict the exact design.

Neither (a) or (b) has anything to do with practicality in the case of retrieving Starlinks.

No.  What you have to show is that there's an economic case to do so.

I'm confused, I laid out the reasons why SpaceX might want to do this in my initial post here, I'm not arguing there is an "economic case", this is not an attempt to reduce the cost.

Not everything SpaceX did with Starlink is to reduce the cost, for example:

1. There's no economic case to make the current generation fully demisable, their original design is not fully demisable, they need additional engineering and had to change out some components to make it fully demisable. And legally they're not required to do this, legally each satellite is allowed to cause 1 in 10,000 probability of casualty on the ground. But it turns out if you have 12,000 satellites, then the aggregated probability of killing somebody on the ground is 45%. So SpaceX changed the plan and made the satellite fully demisable, there's no "economic case" for doing this, they're doing this for non-economic reasons.

2. Same thing for reducing the brightness of Starlink satellites, they didn't have to do this, there's no law that says they must do this, and certainly there's no "economic case" to do this. But they're devoting considerable engineering effort ("An entire team/department" as an astronomer put it) to mitigate this issue.

We're just going to have to disagree.  We're not using the same language.  "Reducing cost" is not the definition of an economic case.  An economic case necessarily involves spending more money for a derived benefit.

Both your examples do have an economic case.  Eliminating a 45% chance of killing someone or mitigating an impediment to astronomy for a modest cost (the PR value) is the definition of an "economic case" decision.

Retrieving some hypothetical 2nd Generation Starlinks that have minimal residual value isn't necessarily economical.  Yes.  You can define some possible benefit (being able to design some greater mass, non-demisable version of Starlink) or PR value (being able to address the ridiculous complaint about the impact to the composition of the atmosphere from the burning-up of deorbiting satellites) but neither of those rise to the level of an economic case.

Yes. You are in the same plane replacing the satellites you are replacing.   Yes they could marshal to a rally point.  But that's not some magic key.   Because no.  They can't be quickly picked up as you stated without significant effort.  Your examples involved hours and hours of EVA.

And the thing you are trying to retrieve is economically worthless.  You can't get around the fact that you are spending significant money and time to retrieve something that is worthless.

Yes.  You can do it.  No.  It makes no sense.

[su27k]

Retrieving some hypothetical 2nd Generation Starlinks that have minimal residual value isn't necessarily economical.

Note I'm not arguing that retrieval is necessarily economical, however you define the "economic case". I'm just pointing out this as a possibility, I don't claim to have a crystal ball that can predict SpaceX's future moves. I went back and checked my original post, I did use the word "could" in my comment, so it should be clear this is discussing a possibility, not a certainty.

In any case, things like "PR value" are hard to evaluate in terms of cost-benefit analysis, even harder to evaluate would be more intangible things like "company's founder and majority shareholder think it's a worthwhile thing to do", so I'm not sure doing a cost-benefit analysis in this case would work. Granted the cost have to be reasonable, which I think it would be.

Finally, we spent money and time to retrieve worthless things all the time here on Earth, it's called "pick up the garbage"...

[AC in NC]

Granted the cost have to be reasonable, which I think it would be.

gather all the old satellites in a new train near the orbit Starship is going to deploy the new satellites, this way Starship can pick them up one by one quickly.

Just saying something could be done isn't interesting.  Most anything can be done.  The question is whether it's practical.  And when I think of the list of things that must be accomplished, I can't see how it would have a reasonable cost. 

Starlinks just can't be picked up quickly.  That last bit is the thing that really raised my hackles.  Just think of how long it takes to dock Dragon.  That's the kind of speed things happen in space.  Yeah one can probably be picked up faster than Dragon but I don't think you are going to get it quick enough to be practical.  Could you get it to an hour?  IDK.  That would make a 60 hr loiter to pick up F9 batch reasonable (is that "quickly"?) but 200 hrs for SS load of double-sized sats.

If the garbage analogy was apt, then you'd have more of an argument.  But full demisability is a severe blow to it.  I suppose if a NEPA ruling goes the wrong way and there's really some legs that develop around the ridiculous concern about incinerated Starlinks polluting the atmosphere then it enters the realm of doing a cost-benefit analysis.  But I fail to see how the costs aren't huge.  But hey SpaceX can surprise you there.  The "benefit" side is really where I think practicality fails.  I just don't see much benefit. 

If you want to build bigger SL's, then do it in a way that retains demisability.  That should be infinitely easier than bringing them back.
If it's the NEPA incineration pollution thing, well that's a counterfactual that could only be evaluated once it raises its specter.  I personally think it's a joke but I think that about a lot of things these days.

[Asteroza]

One could make the argument that a garbage scow OTV that collects dead starlink sats to a specific spot per major inclination set would allow a single starship to do a fulll pickup. There would be a lot of waiting to align ascending node, but no major plane changes. Not unlike the two GEO graveyard spots that gradually collect dead GEO birds as they drift due to nonspherical mass distribution of the earth.

[Llian Rhydderch]

Just thought about this today: Once SpaceX starts launching Starlink using Starship, they could also recover the old Starlink satellites and bring them back to Earth instead of burning them up in the atmosphere. They can do this since the new satellites will need to be launched into the same orbit as the old satellites, so if you're replacing old satellites, the ship is in an ideal position to retrieve the old satellites, store them in the empty cargo bay vacated by the new satellites and land them on Earth.

Why would they want to do this? Two birds with one stone:

I can't understand why this would even seem desirable.

They aren't in the same orbit.  They are in the same plane.  Those a vastly different things and it makes the retrieval of even two satellites at once immensely harder.

I can't begin to imagine an automated way to properly stow a host of Starlinks.

The simple answer for "why this would even seem desirable?" is this:  one day, private companies will have to pay all or most of the cleanup cost for the junk they put into space, at least in LEO. 

Space debris is a "negative externality"--something companies haven't had to account for the cost of and could pass that cost on to humankind in general; but this is only true because of history (the large nation states took no regard for their space junk), and because no. of satellites started small, while space is big.

Air pollution started the same way.  In the 1300s, or in 1800s a smelter could ignore the cost of the stink and debris they were adding to the atmosphere; it was too small a "cost" on society as a whole, and there were fewer smelters. 
By the 1970s, in the developed world at least, the democratic populations were unwilling to eat the cost societally of heavily polluted air and water, and laws and such were passed to "encourage" companies to pay the cost of cleaning it up.  Different forces of course in the Soviet Union and less-democratic societies, with less democratic voice; but the pressures mount there as well, once the population becomes more affluent and as most are living well beyond mere sustenance, as we see beginning to happen in China today (see Beijing air pollution rules).

So, there is beginning to form a forcing function for "why SpaceX might want to do this." 

In fact, if you notice, ALL of the private companies launching megaconstellations are voluntarily or by regulatory authority signing up for the beginnings of a space debris mitigation  plan: all sats down by 5 yrs after end-of-life.  These are societal forces coming into play on the private actors, that even the large nation state actors still give only lip service to.  The "international standard" (a stretch of a term) is "sats deorbited in 25 yrs"; and there are no teeth to enforce when Roscosmos or ESA or NASA or CNSA or US military or other militaries fail to get their space debris out of orbit.

But what has been accepted in the past will not be the future, in 10 yrs, or in 50 yrs.

SpaceX will do what is most economic.  If that is individual sat deorbit; fine.  But its not rational to think there are not good reasons to consider what might be done with huge Starship downmass capacity, especially with the errant sats  (now debris) that are unsuccessful at deorbiting themselves.

[Cherokee43v6]

Just thought about this today: Once SpaceX starts launching Starlink using Starship, they could also recover the old Starlink satellites and bring them back to Earth instead of burning them up in the atmosphere. They can do this since the new satellites will need to be launched into the same orbit as the old satellites, so if you're replacing old satellites, the ship is in an ideal position to retrieve the old satellites, store them in the empty cargo bay vacated by the new satellites and land them on Earth.

Why would they want to do this? Two birds with one stone:

I can't understand why this would even seem desirable.

They aren't in the same orbit.  They are in the same plane.  Those a vastly different things and it makes the retrieval of even two satellites at once immensely harder.

I can't begin to imagine an automated way to properly stow a host of Starlinks.

The simple answer for "why this would even seem desirable?" is this:  one day, private companies will have to pay all or most of the cleanup cost for the junk they put into space, at least in LEO. 

Space debris is a "negative externality"--something companies haven't had to account for the cost of and could pass that cost on to humankind in general; but this is only true because of history (the large nation states took no regard for their space junk), and because no. of satellites started small, while space is big.

Air pollution started the same way.  In the 1300s, or in 1800s a smelter could ignore the cost of the stink and debris they were adding to the atmosphere; it was too small a "cost" on society as a whole, and there were fewer smelters. 
By the 1970s, in the developed world at least, the democratic populations were unwilling to eat the cost societally of heavily polluted air and water, and laws and such were passed to "encourage" companies to pay the cost of cleaning it up.  Different forces of course in the Soviet Union and less-democratic societies, with less democratic voice; but the pressures mount there as well, once the population becomes more affluent and as most are living well beyond mere sustenance, as we see beginning to happen in China today (see Beijing air pollution rules).

So, there is beginning to form a forcing function for "why SpaceX might want to do this." 

In fact, if you notice, ALL of the private companies launching megaconstellations are voluntarily or by regulatory authority signing up for the beginnings of a space debris mitigation  plan: all sats down by 5 yrs after end-of-life.  These are societal forces coming into play on the private actors, that even the large nation state actors still give only lip service to.  The "international standard" (a stretch of a term) is "sats deorbited in 25 yrs"; and there are no teeth to enforce when Roscosmos or ESA or NASA or CNSA or US military or other militaries fail to get their space debris out of orbit.

But what has been accepted in the past will not be the future, in 10 yrs, or in 50 yrs.

SpaceX will do what is most economic.  If that is individual sat deorbit; fine.  But its not rational to think there are not good reasons to consider what might be done with huge Starship downmass capacity, especially with the errant sats  (now debris) that are unsuccessful at deorbiting themselves.

Due to their extremely low deployment orbit, SpaceX has already designed them to be self-deorbting in a 2-3 year timespan (or less) if the Hall Effect thrusters are not used to maintain the orbit.  It would cost more than the material cost of the satellites to fly to each one and collect it or create a system that sweeps them into a collection pool.

It is at the higher orbits (generally above the level of the ISS) where the issue is becoming critical due to the ability of the satellites and the debris from satellite collisions to remain for extensive periods of time.

[DreamyPickle]

Bringing down starlink with starship would be an extremely ineffective measure against space junk since they're small, in low orbits and already designed to deorbit themselves. Active debris removal is a great idea worth exploring but this is not how to do it.

Maybe you could use Starship to launch Starlink-derived garbage collectors which dock and deorbit actual dangerous junk?

This was initially proposed as a way to avoid burning satellites in the atmosphere but the harm from that is almost entirely speculative, unlike the actual known danger of collisions.

[vaporcobra]

I suspect that there will be a major redesign of Starlink sats to take advantage of Starship. I wouldn't be surprised for them to grow to 1000-2000kg and hundreds of GBps each.

SpaceX could also sell the bus and launch as a package deal too. No Geo-sat manufacturer would be able to compete with a bus + launch to GEO for a few million.

Incredibly unlikely that Starlink satellites will ever weigh more than a ton, not unless SpaceX can still affordably mass-produce thousands per year. For a constellation to exist below ~550 km while still maintaining uninterrupted coverage, you NEED ~1500 satellites. ~500 kg is conceivable. 1-2 tons is far less so while maintaining full demisability and massive economies of scale and keeping the per-satellite cost reasonable.

For example, if SpaceX can double satellite mass and, say, 4x or 6x throughput, it could accomplish with 7,000-10,000 satellites what it had planned for >40k and maintain production on the order of 1000 per year, which would sustain significant manufacturing efficiencies.

If we're talking about 2-ton satellites, SpaceX would presumably end up raising throughput 10-20x, reducing the number of satellites needed to ~2000-4000 and thus lowering the required annual output to maybe 200-300 satellites. At that point, Starlink would be more like boutique hypercar production, whereas 1000-2000 per year is closer to 'mass' production at Ferrari or McLaren. And it's worth remembering that SpaceX's proposed 40,000-sat constellation (with decent interlinking and 20 Gbps/sat) would be an 800 Tbps network likely capable of serving like half of the entire global market for fixed broadband.

[savantu]

Based on what they learn, I think they will scrap the plans for 40k constellation and keep a few thousands ( 4k ? ) much more capable ones and with longer planned life ( >10+ years ) at around 550km. Double the weight/fuel, etc.

[raketa]

Based on what they learn, I think they will scrap the plans for 40k constellation and keep a few thousands ( 4k ? ) much more capable ones and with longer planned life ( >10+ years ) at around 550km. Double the weight/fuel, etc.

1/I think they  will go for 40K and every 2 years replace them to  push technology of satellite.
2/End game is not just global internet to anybody even in populated area but I will be not surprise if mobile service will be available later.