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DSL went down.
Stuck new RV Dishy on the lawn .
Bamn! 3x the download speed (of when DSL worked)
This is in a waitlist area
Now for a better mount....
Stuck new RV Dishy on the lawn .
Bamn! 3x the download speed (of when DSL worked)
This is in a waitlist area
Now for a better mount....
And that's why SX's approach to the problem with starlink is so important--they've built the full lifecycle requirement in from the beginning. DOA sats naturally deorbit very quickly, and they're not shy about proactively deorbiting a slightly malfunctioning sat (rather than stringing it along on redundancies and workarounds and patches, as is industry standard), so there's a very small chance they're actually going to have dead sats flying in unfavorable places. They're also leaps and bounds ahead of anyone else in automated COLA...though the fact that they're willing to conjunct closer than anyone else sort of offsets the statistical upside of being really good at COLAs.
Anyway, point being, SX solves the cleanup problem by not making a mess in the first place. Not every mega constellation in the works is taking the same approach...
Of course, from the land of nothing-is-perfect, Starlink's numbers mean they will suffer more than anyone else from a Kessler scenario.
CyberGus
Not Just a Member
dhanson865
Well-Known Member
In case you don't know the existing starlink satellites all have the equivalent of FSD installed. They have the ability to avoid collisions with no orders from the ground required.
The problem Kessler propsed is that there might be a scenario where there is no safe path no matter how you try to dodge if the debris field gets too dense.
Yes, but your description is lacking context. The satellites don't have "radar" or any way of sensing an imminent collision. These things are zipping around at 18,000 miles per hour. From SpaceX:
“Space is populated with existing debris, tracked by the [United States Military] 18th Space Control Squadron. Starlink utilizes an automated collision avoidance system, ingesting data from the 18th,” the company told the Commission. “Satellites can autonomously evaluate risk and plan avoidance maneuvers, without human input. Humans are still present in an oversight role, as an added measure of safety,”
So, based on uploaded data, a Starlink satellite can plan and execute an avoidance maneuver. With humans in the loop just in case.
Okay okay, you two are both right.
That capability is mind boggling to me. And it certainly is needed. As per NASA:
Even though, long term, Starlink sats will all be orbiting at about 340km altitude so a lot of that debris will not be a concern, there is still a lot of space junk to worry about.
How is that altitude not a concern for debris? Just curious.
Don't eventually all these objects when they die, slowly get into lower altitudes before eventually entering atmosphere and burning up? Which means they will have a chance to interfere with any objects orbiting below them?
Your interpretation of my post is at odds with what I intended to convey.
I did not say that space debris is “not a concern” for Starlink.I quoted NASA as saying that there are tens of thousands of pieces of debris in orbit. Then I said that not all of that debris is a collision concern for the Starlink constellation given that, like any object in orbit, it is fixed within a set altitude. The debris is of course not all at the same altitude.
Only some fraction of the total amount of space debris is a risk for a sat at a given altitude.
Does that make sense or am I missing something? (The latter is always possible)
In high orbits there is basically no drag to decay the orbit of debris. The Stalink sats are in a low enough orbit that there is measurable drag and uncontrolled debris at those altitudes will naturally fall out of orbit within a reasonable amount of time. In this case, reasonable time is less than 10 years.
Collision risk is a statistical thing, and time is a big part of the statistical equation. The main thing that causes natural orbital decay is atmospheric drag. As altitude increases atmospheric density decreases, so there’s less drag on an object and the object takes longer to re-enter…and thus more time for that object to be in the way of another object. Conversely a low altitude object experiences more drag and will lose km’s faster…so the risk is still there, it’s just the temporal element makes it much more manageable.
Re-entry timeline is a highly object dependent thing, but for reference, most of the sats that are getting dropped into ‘low’ LEO (less than 600 or so) aspire to re-enter within the [current, but proposed to be changed] 25 year requirement. Usually the math comes out to a predicted 5-15 years, absent propulsive (or high drag) assistance.
Yes. Existing debris will become an increasing collision risk as time moves on and the altitudes naturally decay into lower altitudes, as the ‘surface’ of the orbital shell reduces (the surface area of a sphere is proportional to the radius squares), the orbital period reduces (so, more possible conjunctions with other objects) and precession increases (the rate as which the circular orbit rotates, again statistically increasing conjunctions).
What’s most important to understand is that future debris is a serious problem that’s only going to get worse, and certainly when entities are not as forward leaning with respect to debris as someone like SX. For instance, even with the ‘small’ current Starlink constellation, they’re doing A LOT of COLA maneuvers just to get of their own way—like, an unprecedented amount (though that’s a bit of a statement of the obvious given their quantities). That gets exponentially worse with increasing quantities of satellites, and then even more so when altitudes are reduced, for the reasons noted above (though Kessler clouds at lower altitudes will at least re-enter on the order of a few years vs many years).
A good case study is the kosmos-iridium cloud in the ~800’s or so. That was ONE collision (admittedly, just about the worst kind of collision) over 10 years ago and even today nobody is putting satellites (or planning to put satellites) at that altitude because the debris cloud is too hard to fly through.
A similar collision at, say, 550 or so would be absolutely devastating for decades. 350 would be terrible for a few years, including for launches, since everyone would have to frogger their way through.
SpaceX and OneWeb have reached a mutual understanding of co-existence.
And in related news, SpaceX and Viasat are still not friends.
Viasat controlling Inmarsat will be a pretty BFD, as there will be significant FSS and MSS rights under one roof.
Viasat controlling Inmarsat will be a pretty BFD, as there will be significant FSS and MSS rights under one roof.
Ignoring all the TLAs I don't know, would you happen to have a link to SpaceX's original complaint about Viasat's alleged frequency violation?
Can't find--rudimentary searches return a version of this most recent news, and then before that Viasat's complaining to the FCC to stop starlink expansion. But...I recall SX's argument against Viasat was rooted in logic but not a slam dunk, and I also recall it sort of shot itself in the foot with bluster/hyperbole. I'm also pretty sure it was specifically a response to the aforementioned Viasat complaints. Can't not drama, as it were.
Barely related, in my search attempts to answer the above, Google suggested these useful criteria:
And:
BFD = Big ****ing Deal
FSS = Fixed Satellite Services
MSS = Mobile Satellite Services (Think: Iridium, SXM, Inmarsat, Globalstar)
The historical differentiation between the latter two [fixed vs mobile refers to the user] are and/or will be the root of various complaints against Starlink being used for moving vehicles. There are specific frequency bands allocated to fixed vs mobile space use--some might overlap but not all, IIRC.
There might be an updated version of this allocation chart, but its a fun rat hole all the same.
Barely related, in my search attempts to answer the above, Google suggested these useful criteria:
And:
BFD = Big ****ing Deal
FSS = Fixed Satellite Services
MSS = Mobile Satellite Services (Think: Iridium, SXM, Inmarsat, Globalstar)
The historical differentiation between the latter two [fixed vs mobile refers to the user] are and/or will be the root of various complaints against Starlink being used for moving vehicles. There are specific frequency bands allocated to fixed vs mobile space use--some might overlap but not all, IIRC.
There might be an updated version of this allocation chart, but its a fun rat hole all the same.
