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What will protect those assets? Isn't now the time to dust off Dyna-Soar?

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How long for Iran proxy and alike to be able to shoot Low earth orbit satellites? Do you think these kind of groups would not crave shooting one or littering low orbits with debris of several?
 
How long for Iran proxy and alike to be able to shoot Low earth orbit satellites? Do you think these kind of groups would not crave shooting one or littering low orbits with debris of several?
Dynasoar would do nothing to stop that.
 
How long for Iran proxy and alike to be able to shoot Low earth orbit satellites? Do you think these kind of groups would not crave shooting one or littering low orbits with debris of several?

Perhaps, but they will likely make a lot of enemies that way. There is no realistic way of stopping someone from trashing low earth orbit; if the Iranians want to just boost ten tons of ball bearings or fishing weights into orbit that is a goal they can achieve now.
 
Perhaps, but they will likely make a lot of enemies that way. There is no realistic way of stopping someone from trashing low earth orbit; if the Iranians want to just boost ten tons of ball bearings or fishing weights into orbit that is a goal they can achieve now.
Did you actually try to calculate, how ridiculously small sector of orbit those ten tons of ball bearings could block?
 
Did you actually try to calculate, how ridiculously small sector of orbit those ten tons of ball bearings could block?

I am presuming that the original post by TomcatViP was concerning the knock on effect of multiple satellites being disintegrated in orbit, causing a cascading effect of debris in LEO (Kessler Syndrome). Engaging even a dozen satellites out of a constellation of hundreds would have rather negligible direct effect, but ultimately numerous follow on collisions over time might produce a more permanent problem. So if that is the long term goal of a rouge state, for example Iran, then there is no need to target specific satellites. They would only have to send a cloud of projectiles in a counter orbit to one satellite, or ideally an orbital plane with multiple satellites, to likely achieve a hit eventually. Starlink should provide all the feeder stock anyone could hope for. This would not threaten a proliferated constellation immediately, but if things snowballed it might ultimately threaten it over time.
 
I am presuming that the original post by TomcatViP was concerning the knock on effect of multiple satellites being disintegrated in orbit, causing a cascading effect of debris in LEO (Kessler Syndrome). Engaging even a dozen satellites out of a constellation of hundreds would have rather negligible direct effect, but ultimately numerous follow on collisions over time might produce a more permanent problem. So if that is the long term goal of a rouge state, for example Iran, then there is no need to target specific satellites. They would only have to send a cloud of projectiles in a counter orbit to one satellite, or ideally an orbital plane with multiple satellites, to likely achieve a hit eventually. Starlink should provide all the feeder stock anyone could hope for. This would not threaten a proliferated constellation immediately, but if things snowballed it might ultimately threaten it over time.
Kessler syndrome is greatly overestimated. It basically means that the most heavy-used orbits would become less economically useful due to expected work time of satellites decreasing significantly (due to increasing probability of hitting the debris). And on low orbit it would be only a temporary effect anyway; due to atmospheric friction, most of debris would rather quickly deccelerate and burn.
 
Kessler syndrome is greatly overestimated. It basically means that the most heavy-used orbits would become less economically useful due to expected work time of satellites decreasing significantly (due to increasing probability of hitting the debris). And on low orbit it would be only a temporary effect anyway; due to atmospheric friction, most of debris would rather quickly deccelerate and burn.

There’s still hundreds of fragments from the last Russian ASAT test being tracked, and I believe some are expected to stay up for decades. I cannot speak to the probability of a cascading effect, but it certainly seems like were that to happen, low earth orbit would have drastically increased collision hazards for a generation or two.

But in any case, it is unlikely there is any cost effective or politically acceptable way of stopping direct ascent KE weapons or other intentional orbital shrapnel from being deployed. The best deterrent IMO is too make any such effort meaningless in the short term: there is no point in launching kinetic attacks if it is not going to significantly degrade your opponent’s capabilities during a conflict.
 
preventing or mitigating such nuisances would need a platform up there ready to intervene.

There is a favorable factor here, however: rogue actors that might potentially have the means and intend to disrupt LEO are not scattered all across the globe. At any time, there would be one or two locations where such actions might be attempted. Hence, we can define a patrolling area where to enforce satellite protection.
Ideally, the enforcer is a vehicle that is multi-tasked across a vast range of missions and pre-deployed on-orbit to hasten operational delay upon an alert. Cross range and the ability to dive into the atmosphere to proceed with kinetic intercept of an ascending kill vehicle inside the atmosphere would seem more appropriate than a ground based system.

Retriving damaged satellites and collecting debrits would be a plus for a sister vehicle, that could be a civilian asset.
 
preventing or mitigating such nuisances would need a platform up there ready to intervene.

There is a favorable factor here, however: rogue actors that might potentially have the means and intend to disrupt LEO are not scattered all across the globe. At any time, there would be one or two locations where such actions might be attempted. Hence, we can define a patrolling area where to enforce satellite protection.
Ideally, the enforcer is a vehicle that is multi-tasked across a vast range of missions and pre-deployed on-orbit to hasten operational delay upon an alert. Cross range and the ability to dive into the atmosphere to proceed with kinetic intercept of an ascending kill vehicle inside the atmosphere would seem more appropriate than a ground based system.

Retriving damaged satellites and collecting debrits would be a plus for a sister vehicle, that could be a civilian asset.

The nature of orbital mechanics means that the only way to “patrol” a particular part of the earth’s surface is to be at an altitude so high as to be useless for low earth orbit. So whatever defense mechanism you are envisioning would still have to have more or less global coverage.

But the other problem is that even if an organization had a physical method for shooting down direct ascent KE weapons or unauthorized space launches (and that is pretty much just a fantasy right now anyway), how is it going to be politically acceptable to simply fire on other countries’s rockets?
 
DEW as in Distance Early Warning? That already exists.
Direct Energy Weapon.

Other news:


 
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@Forest Green : I understand that Troposcatter is an atmospheric communication device, probably using tropopause reflection for beyond LOS (BLOS) communication.
It's a substitute to satellite com, hence probably not related to the Space Force.
 

Isn't SM-3 direct ascent? I would have thought the quantity of them would class as significant?
 


Isn't SM-3 direct ascent? I would have thought the quantity of them would class as significant?

Try reading the report. It talks about the ASAT potential of both SM-3 and GBI. (pg.58 ff) The report marks the US direct-ascent LEO ASAT capability as "uncertain" because it is unclear to what extent that US can or would use these weapons in an ASAT capacity.
 


Isn't SM-3 direct ascent? I would have thought the quantity of them would class as significant?

The current version is not really kinetically capable of LEO; that satellite was going to re-enter. Blk 1B with the 21” wide second stage will probably be an ASAT capable weapon.
 
Try reading the report. It talks about the ASAT potential of both SM-3 and GBI. (pg.58 ff) The report marks the US direct-ascent LEO ASAT capability as "uncertain" because it is unclear to what extent that US can or would use these weapons in an ASAT capacity.
I get your point but as of 2022, 500 SM-3s had been produced. That's pretty significant. Does anyone else have 500+ ASAT-capable missiles.

Is the table on page 01-16 correct, "apogee... 2,700km,"? That was only a Block IA. Satellite apogee maybe??

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The current version is not really kinetically capable of LEO; that satellite was going to re-enter. Blk 1B with the 21” wide second stage will probably be an ASAT capable weapon.
I think you mean Blk IIAs, Blk IBs still have original diameter.

It does not need to be capable of LEO itself to hit a LEO satellite. If it was, then it would likely be defined as co-orbital, since it uses the same orbit. USA-193 was destroyed at an altitude of 247km by a Blk IA. From what I understand, a satellite is a relatively easy target compared to an RV.
 
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Is the table on page 01-16 correct, "apogee... 2,700km,"? That was only a Block IA. Satellite apogee maybe??

Debris apogee, I believe. The actual intercept was around 250 km. The satellite was in a roughly circular orbit that started as 349 x 365 km and decayed down to 244 x 261 km.

 
I get your point but as of 2022, 500 SM-3s had been produced. That's pretty significant. Does anyone else have 500+ ASAT-capable missiles.

Is the table on page 01-16 correct, "apogee... 2,700km,"? That was only a Block IA. Satellite apogee maybe??

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I think you mean Blk IIAs, Blk IBs still have original diameter.

It does not need to be capable of LEO itself to hit a LEO satellite. If it was, then it would likely be defined as co-orbital, since it uses the same orbit. USA-193 was destroyed at an altitude of 247km by a Blk IA. From what I understand, a satellite is a relatively easy target compared to an RV.

Yes, blk2A.

I meant that it could not intercept a satellite in a conventional LEO orbit, not that any version was capable of achieving stable orbit. The target’s orbit had descended well below the perigee of most any satellite. But the 2a probably does have enough performance to hit objects in some lower orbits.
 
Yes, blk2A.

I meant that it could not intercept a satellite in a conventional LEO orbit, not that any version was capable of achieving stable orbit. The target’s orbit had descended well below the perigee of most any satellite. But the 2a probably does have enough performance to hit objects in some lower orbits.
That's where I disagree, it absolutely can. I think you'd be surprised by how many satellites orbit below 250km, or descend below that in elliptical orbits. USA-193 was in an elliptical orbit with an apogee of 2,700km for instance. Yes, it was out of control, and that's why it was targeted. This does not imply in any way that an in control one couldn't be targeted, it's just that it doesn't make sense to target the healthy ones in a test. If anything, a decaying orbit is harder not easier to predict and guide on.

ASM-135 hit a satellite at 555km with relatively ancient technology, and a missile that likely has much less range than a Blk IIA, even when launched from an F-15 at 38,000ft and M0.9.
 
Regarding Sierra Ghost, from the article above:
Additional background on Sierra Space Ghost:

+ On-orbit time of five years, vehicles are outfitted with pre-determined supplies (a survival kit, inflatable boat, rations, weaponry, etc.) pre-staged on orbit

+ On call-up, the system re-orients and begins re-entry/targeting cycle; the de-orbit motor slows the vehicle to 7,000 meters per second


+ Gravity then captures the vehicle and it begins to re-enter Earth's atmosphere with the thermal protection shield withstanding temperatures up to 2,000 degrees Fahrenheit

+ Once through atmosphere, the shield is then discarded leaving just the requested payload and a parafoil

+ At the right altitude, the parafoil is released and it steers the payload to the required area within 100 meters
 
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