For Questions That Don't Merit Their Own Thread

[monophonic]

3 hours ago, StrandedonEarth said:

Not only that, but the faster you go the more massive you get, requiring constantly increasing thrust to maintain a constant acceleration 

But for you on-board time gets slower so you still feel the same acceleration. It's just everybody else who thinks your acceleration is reducing.

[wumpus]

9 hours ago, StrandedonEarth said:

Not only that, but the faster you go the more massive you get, requiring constantly increasing thrust to maintain a constant acceleration 

Pretty sure that relativistic mass was a mistake in special relativity that needed to be corrected in general relativity.  My understanding is that Newton's second law should really be F=dp/dt (derivative of momentum) and that momentum increases to infinity.  Velocity is then scaled by the Lorentz equations to asymptotically approach c.

If you assume "relativistic mass" under general relativity you then have issues of high-speed massive objects becoming black holes and then leaving said hole.  This confused me for awhile as some physics professors at my college refused to teach F=ma (although my first semester prof did) so at least half the class refused to accept such an equation.  When I realized the black hole bit I looked up the rest it became more clear.

[TheSaint]

17 hours ago, Rutabaga22 said:

Why math have a problem with equations? There is no reason math is a "Problem".

Apparently you need this shirt.

[SunlitZelkova]

1. Can IR sensors used on ballistic missile early warning satellites pick up any hot heat signature, or only missiles/rockets?

I am aware they can see Tu-22Ms going on full afterburner, but I am wondering if they would be able to see a direct ascent interceptor (like SM-3) being fired at them. Discount the SC-19 as that is based on the DF-21 and thus would be very visible.

2. What are the prospects of using very small satellites (cubesat or perhaps even smaller sats) as co-orbital interceptors?

A normal sized satellite with a “gun” could be spotted and the EW sat could maneuver, but don’t smaller objects get missed at times? I’m thinking along the lines of hitting stuff in GEO, not LEO.

3. What are the prospects for time-on-target (TOT) strikes on satellites? Could two Aegis ships in different areas of the world fire their missiles and hit two satellites within a second or two of each other, so long as the orbits and positions of ships permitted such a strike?

4. Would it be possible to coordinate DA strikes with co-orbital GEO strikes, or is the margin of error too large when trying to hit something co-orbitally compared to direct ascent?

What I am pondering is trying to eliminate a small sized constellation (1-10 but the scenario has 5) in one go.

[Rutabaga22]

Was the sea dragon second stage supposed to have an expanding bell? My friend told be that was a plan, but I have never heard about this.

[kerbiloid]

5 hours ago, SunlitZelkova said:

1. Can IR sensors used on ballistic missile early warning satellites pick up any hot heat signature, or only missiles/rockets?

I am aware they can see Tu-22Ms going on full afterburner, but I am wondering if they would be able to see a direct ascent interceptor (like SM-3) being fired at them. Discount the SC-19 as that is based on the DF-21 and thus would be very visible.

In the case of MH17 incident they pretend detecting AA missile launches.

Light hull means thin hull. Vulnerable to the EM shot.

Also, even the modern portable IR-homing AA missiles aren't just AA, they also check UV signature to discriminate decoys.

5 hours ago, SunlitZelkova said:

2. What are the prospects of using very small satellites (cubesat or perhaps even smaller sats) as co-orbital interceptors?

A normal sized satellite with a “gun” could be spotted and the EW sat could maneuver, but don’t smaller objects get missed at times? I’m thinking along the lines of hitting stuff in GEO, not LEO.

It needs delta-V to jump to the target, so a pack of engines and a fuel system (tanka, valves) which can't be effectively scaled down.

Its cross-section to mass ratio is high, so the drag is many times greater, so it will be deorbiting nuch faster than the target satellites.

5 hours ago, SunlitZelkova said:

3. What are the prospects for time-on-target (TOT) strikes on satellites? Could two Aegis ships in different areas of the world fire their missiles and hit two satellites within a second or two of each other, so long as the orbits and positions of ships permitted such a strike?

Probably more poor than on simultaneous hitting two planes within a second. (Has that ever happened?)

4 hours ago, Rutabaga22 said:

Was the sea dragon second stage supposed to have an expanding bell?

Yes.

( https://en.wikipedia.org/wiki/Sea_Dragon_(rocket) )

http://neverworld.net/truax/Sea_Dragon_Concept_Volume_1.pdf

Search "expandable"

[SunlitZelkova]

56 minutes ago, kerbiloid said:

Probably more poor than on simultaneous hitting two planes within a second. (Has that ever happened?)

I think no, because air combat is more “seat of the pants”/shoot first and on instinct compared to say, planning a cruise missile strike or shooting down a satellite. If the orbits are known you might have several hours to prepare in a detailed manner and weeks of basic planning time.

[DDE]

Don't think I've ever seen a first-person ejection video

 

[magnemoe]

12 hours ago, SunlitZelkova said:

I think no, because air combat is more “seat of the pants”/shoot first and on instinct compared to say, planning a cruise missile strike or shooting down a satellite. If the orbits are known you might have several hours to prepare in a detailed manner and weeks of basic planning time.

Yes targets for surface to air missiles or air to air combat is much more an target of opportunity. 
Now you could set up an ambush, an SAM battery getting feed the location of an flight of enemy planes then turn on the radar and fire multiple missiles at different targets. 
Also think an stealthy platform like F-22 could pull this off.

Attacking an fixed target this is way more common, coordinated artillery strikes or air strikes was common during WW 2. 
However you rarely need seconds between hits, exception is the classical ambush there you hit the infantry before they can find cover.

[kerbiloid]

I guess, any flight where RCS or low thrust mode is enabled for attitude control can't be enough precise to fit a several minutes interval.

These devices are exactly to compensate the unpredictable errors.

Edited October 23, 2022 by kerbiloid

[ARS]

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

[Rutabaga22]

1 hour ago, ARS said:

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

I'd argue that cann't be decided with 1 absolute answer. Depends on volume of ammo exploded, the way it exploded, etc.

[SunlitZelkova]

5 hours ago, ARS said:

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

Depends on the definition of recognizable maybe? Visually, certainly no, but I am not familiar at all with DNA recognition technology and how capable it is.

[kerbiloid]

5 hours ago, ARS said:

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

Usually the turret is blown away by the powder burning.

[razark]

17 minutes ago, kerbiloid said:

Usually the turret is blown away by the powder burning.

Yes, but the turret still exists, so one could examine it for whatever remains inside.

 

If I turn on the blender, what can I determine from what's left inside the blender?
isn't really answered by
Turning on the blender causes the motor to spin the blades.

Edited October 24, 2022 by razark

[DDE]

6 hours ago, ARS said:

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

I've got this vague, vague memory from reading about ISU-152 almost two decades ago that one of the Tiger aces (Carius?) survived a turret-tossing.

[kerbiloid]

A plenty of videos from the current events make to doubt in the Otto's hunter's story.

[sevenperforce]

On 10/23/2022 at 7:05 AM, DDE said:

Don't think I've ever seen a first-person ejection video

 

Engagement in Ukraine?

There's a second plane visible streaking past as his chute opens but it's too far to see what it is. Probably another Su-25, but since the Su-25 is flown by both Russia and Ukraine that wouldn't make much of a difference.

 

[DDE]

11 minutes ago, sevenperforce said:

Engagement in Ukraine?

There's a second plane visible streaking past as his chute opens but it's too far to see what it is. Probably another Su-25, but since the Su-25 is flown by both Russia and Ukraine that wouldn't make much of a difference.

A Ukrainian video is highly unlikely given the source, and somewhat unlikely given Russian voice comms. So, RuASF or Ru PMC.

[sevenperforce]

6 hours ago, DDE said:

A Ukrainian video is highly unlikely given the source, and somewhat unlikely given Russian voice comms. So, RuASF or Ru PMC.

Oh, absolutely a Russian video.

I was just wondering whether this is a video from an active aerial military engagement ongoing in the Russo-Ukrainian War, or something else like a training exercise. I don't speak Russian so I have no idea what the comms are discussing.

If it's a training exercise, then the plane streaking past is clearly a training partner. If it's an active engagement, then the other plane might be Ukrainian. 

[JoeSchmuckatelli]

3 minutes ago, sevenperforce said:

Oh, absolutely a Russian video.

I was just wondering whether this is a video from an active aerial military engagement ongoing in the Russo-Ukrainian War, or something else like a training exercise. I don't speak Russian so I have no idea what the comms are discussing.

If it's a training exercise, then the plane streaking past is clearly a training partner. If it's an active engagement, then the other plane might be Ukrainian. 

The altitude flown and the fact that I first saw it the day before yesterday on a Ukraine focused board tells me that it's from the current conflict. 

(My pilot friends tend to share stuff like that, and I never saw it before) 

FWIW - RU has had several non combat aerial accidents, and they have been reported as regular news - but 'exciting' things like that don't make it out. 

[SunlitZelkova]

3 hours ago, sevenperforce said:

Oh, absolutely a Russian video.

I was just wondering whether this is a video from an active aerial military engagement ongoing in the Russo-Ukrainian War, or something else like a training exercise. I don't speak Russian so I have no idea what the comms are discussing.

If it's a training exercise, then the plane streaking past is clearly a training partner. If it's an active engagement, then the other plane might be Ukrainian. 

It’s been geolocated by OSINT people on Twitter, and it apparently comes from a training exercise.

It was reportedly in Belgorod, and slammed into a power line.

I don’t know how reliable such estimates are though.

[JoeSchmuckatelli]

2 hours ago, SunlitZelkova said:

It’s been geolocated by OSINT people on Twitter, and it apparently comes from a training exercise.

It was reportedly in Belgorod, and slammed into a power line.

I don’t know how reliable such estimates are though.

Whoops - well I guess I was wrong!

(That dude was flying REALLY low; the kind of stuff you only see when you're getting shot at, usually)

[miklkit]

On 10/23/2022 at 4:22 PM, ARS said:

If a tank got hit and it detonates the ammo inside, so much that the turret gets blown off the hull, realistically speaking is there anything left from the crew's remains to be recognizable?

No.  At most there might be a few teeth.  Maybe.  Usually there is nothing left at all.

[kerbiloid]

Usually the pilots never call each other "Brother" in the radio communication. They use callsigns and mention their own.

The pilot is wearing green camouflage (the small mirror at first seconds) to hide from enemies, but keeps standing near the orange parachute, so unlikely is under possible attack.

Unless it's from MSFS, it looks a training video.