Ghost Rider Compesators

What a compesator official on paper rated limit is still likely highly conservative of what it is actual capable of. Good engineers will stay on the cautious side of things when committing things to paper.

pnakasone wrote:What a compesator official on paper rated limit is still likely highly conservative of what it is actual capable of. Good engineers will stay on the cautious side of things when committing things to paper.

Earlier in the series, people talked about 80% nominal acceleration, versus full military power (i.e. 100%). 100% means 100%; there is zero safety margin. One can attempt to go over 100%, such as during Honor's midshipwoman cruise in the short story "Ms. Midshipwoman Harrington". In which case it might work, but you'd never know when it would fail, because it happens instantaneously and without warning.

Jonathan_S wrote:I also did a little number crunching on your quote from SoF and it looks like they must have been in excess of 16,000 gravities.
From the Quentin Saint-James numbers it appears they carried roughly 290 km/s with them from hyper - which adds up to ~450,000 km compared to starting at zero.

26 minutes at 15,900g would give you 10.54 LM, or 189,601,776 km. Factor in the initial velocity would alter that to 10.56 LM (190,054,176 km). Basically the numbers from the quote. (And incidental 0.81c) But remember the drones had to be even quicker than that because they'd already reached turnover and started decelerating.

Though the claim that they were going for a zero/zero intercept; and the above calcs had them acceperating 86% of the way there; not the way to achieve zero/zero.

Ok, I kept going and rejiggered my spreadsheet a bit and think I got roughly the zero/zero accel profile given the few data points we had; and it's right around 20,000g.

At that point, including the 290 km/s carried over, the drone accelerates for 17.6 minutes (actually 1054 seconds) at 20,000g reaching a peak velocity of 0.69c and covering 109,022,598 km (roughly 6 LM) towards the planet and performs it's turnover. It then slows for another 8.4 minutes (actually 506 seconds) dropping its velocity to 0.39c and bringing us to 10.48 LM at the 26 minute mark (roughly matching the quoted values).
Zero/zero would then be achieved at the planet, 12.1 LM away from launch, after roughly 35 total minutes of flight.


Wow, 20,000g! Not a spot on a missile capable of 92,000g but still damned impressive for something capable of hours instead of minutes of flight. (And thus ends this edition of fun with spreadsheets)

I believe the quote is:
"A good engineer is always a wee bit conservative, at least on paper. "

I would suspect that any compensation on a GR drone would be designed to counter the jerk than the acceleration.
Passengers, of course, need one designed around countering acceleration.

Basically, if a Ghost Rider drone did have a compensator, it's likely 'focused' wrong for passengers.

Which I think is what Skimpers post was leading too.

Sent from my SM-G920I using Tapatalk

Jonathan_S wrote:

Jonathan_S wrote:I also did a little number crunching on your quote from SoF and it looks like they must have been in excess of 16,000 gravities.
From the Quentin Saint-James numbers it appears they carried roughly 290 km/s with them from hyper - which adds up to ~450,000 km compared to starting at zero.

26 minutes at 15,900g would give you 10.54 LM, or 189,601,776 km. Factor in the initial velocity would alter that to 10.56 LM (190,054,176 km). Basically the numbers from the quote. (And incidental 0.81c) But remember the drones had to be even quicker than that because they'd already reached turnover and started decelerating.

Though the claim that they were going for a zero/zero intercept; and the above calcs had them acceperating 86% of the way there; not the way to achieve zero/zero.

Ok, I kept going and rejiggered my spreadsheet a bit and think I got roughly the zero/zero accel profile given the few data points we had; and it's right around 20,000g.

At that point, including the 290 km/s carried over, the drone accelerates for 17.6 minutes (actually 1054 seconds) at 20,000g reaching a peak velocity of 0.69c and covering 109,022,598 km (roughly 6 LM) towards the planet and performs it's turnover. It then slows for another 8.4 minutes (actually 506 seconds) dropping its velocity to 0.39c and bringing us to 10.48 LM at the 26 minute mark (roughly matching the quoted values).
Zero/zero would then be achieved at the planet, 12.1 LM away from launch, after roughly 35 total minutes of flight.


Wow, 20,000g! Not a spot on a missile capable of 92,000g but still damned impressive for something capable of hours instead of minutes of flight. (And thus ends this edition of fun with spreadsheets)

That is indeed some impressive acceleration, made even more impressive that the Sollies didn't even notice a thing.

Did your spreadsheet charts account that the drones were still 90 lightseconds short of Mobius and presumably still slowing? That might reduce their speed ever so slightly, but not by a very noticeable factor.

And that's only their possible max stealthed speed, if you were willing to sacrifice some stealthiness for even higher velocity, they must be capable of pushing 30, maybe even as high as 40k gravs with no stealth at all.

Somtaaw wrote:

Jonathan_S wrote:Ok, I kept going and rejiggered my spreadsheet a bit and think I got roughly the zero/zero accel profile given the few data points we had; and it's right around 20,000g.

At that point, including the 290 km/s carried over, the drone accelerates for 17.6 minutes (actually 1054 seconds) at 20,000g reaching a peak velocity of 0.69c and covering 109,022,598 km (roughly 6 LM) towards the planet and performs it's turnover. It then slows for another 8.4 minutes (actually 506 seconds) dropping its velocity to 0.39c and bringing us to 10.48 LM at the 26 minute mark (roughly matching the quoted values).
Zero/zero would then be achieved at the planet, 12.1 LM away from launch, after roughly 35 total minutes of flight.


Wow, 20,000g! Not a spot on a missile capable of 92,000g but still damned impressive for something capable of hours instead of minutes of flight. (And thus ends this edition of fun with spreadsheets)

That is indeed some impressive acceleration, made even more impressive that the Sollies didn't even notice a thing.

Did your spreadsheet charts account that the drones were still 90 lightseconds short of Mobius and presumably still slowing? That might reduce their speed ever so slightly, but not by a very noticeable factor.

Yes, in fact that information was critical to figuring out the profile. (Well it wouldn't have been if the text had simply given us the total expected transit time - but since it didn't I had to get numbers to fit based on accelerating ~halfway, then decelerating until 90 LS short of the planet, then making sure that that was 26 minutes after launch.

(Well technically I set the sheet up the other way, fixed the time and saw if the distances worked out; adjusting acceleration and endurance until they did.

And that's only their possible max stealthed speed, if you were willing to sacrifice some stealthiness for even higher velocity, they must be capable of pushing 30, maybe even as high as 40k gravs with no stealth at all.

Other quotes have said their max truly stealthy acceleration is only 5000g - so I'm guessing that Mobius didn't have a good sensor network in place.
I'd bet that 20,000g is pretty darned close to the drone's best acceleration - but that's just a feeling based on them needing, for plot reasons, to be significantly slower than 1/2 power missiles at 46,000g.

Jonathan_S wrote:

Somtaaw wrote:And that's only their possible max stealthed speed, if you were willing to sacrifice some stealthiness for even higher velocity, they must be capable of pushing 30, maybe even as high as 40k gravs with no stealth at all.

Other quotes have said their max truly stealthy acceleration is only 5000g - so I'm guessing that Mobius didn't have a good sensor network in place.
I'd bet that 20,000g is pretty darned close to the drone's best acceleration - but that's just a feeling based on them needing, for plot reasons, to be significantly slower than 1/2 power missiles at 46,000g.

Part of those plot reasons is unlike missile impeller nodes that can't be shut down and then restarted (using the same set of nodes), a drone's nodes can be shut down and restarted many, many times over the lifetime of the nodes. In this regard, drone impeller nodes are more similar to the beta nodes on pinnnces, LACs, and starships than they are to the impeller nodes used on missiles.

I just wonder because all spaceships like airplanes have structural flaws develope at sub 1G accelerations. At 5000+G acceleration these probes would be failing all the time. The only reason ships in the honorverse don't have structural failings is that they have wedges and compensators. It is the same problem with the ships that Honor used without a compensator nor wedge. At 150G they would be crushed like the plane that crashed into the Pentagon. Compensators effectively reduce the structural effect on ships to zero. While for Honor she had a 5G interior grav plated effect, that wouldn't prevent the ship from experiencing the full 200+G effects. If ships can ignore 200+ G effects they should be able to land on planets without damaging themselves. If Ghost rider probes can ignore 5000-15000 G effects, artillery shells electronics can for a few tenths of a second. Maybe solid state electronics could survive. Any probe would be crushed with each maneuver. Ghost rider probes are not armoured.

So if they don't have compensators how do they survive being crushed by the Gees?

Lord Skimper wrote:I just wonder because all spaceships like airplanes have structural flaws develope at sub 1G accelerations. At 5000+G acceleration these probes would be failing all the time. The only reason ships in the honorverse don't have structural failings is that they have wedges and compensators. It is the same problem with the ships that Honor used without a compensator nor wedge. At 150G they would be crushed like the plane that crashed into the Pentagon. Compensators effectively reduce the structural effect on ships to zero. While for Honor she had a 5G interior grav plated effect, that wouldn't prevent the ship from experiencing the full 200+G effects. If ships can ignore 200+ G effects they should be able to land on planets without damaging themselves. If Ghost rider probes can ignore 5000-15000 G effects, artillery shells electronics can for a few tenths of a second. Maybe solid state electronics could survive. Any probe would be crushed with each maneuver. Ghost rider probes are not armoured.

So if they don't have compensators how do they survive being crushed by the Gees?

Because:
a) it's space, there's no (major) gravity there, and there's no atmosphere to cause drag and/or other motion
b) they use molycircs rather than silicon boards. Which means their computers are even better than our solid-state equipment, which also means they can make a solid missile, or drone in this case, that doesn't HAVE anything that might slide around and cause structural stress outside of what should happen from acceleration derived motion.


Look at modern fighter planes, and how they've changed the pilot seat from straight up and down, to more of a reclined couch. This was a design change due to the accelerations fighter pilots encounter, and between their flightsuits, the couches, and various other techniques I'm sure exist and I don't know... fighter pilots commonly withstand acceleration forces that would knock out virtually any civilian and do it for longer than you or I could handle it.

If we can do it with a manned fighter, you actually think we couldn't do the same thing with an unmanned drone that has even better solid state circuitry than we can build today?

Lord Skimper wrote:I just wonder because all spaceships like airplanes have structural flaws develope at sub 1G accelerations. At 5000+G acceleration these probes would be failing all the time. The only reason ships in the honorverse don't have structural failings is that they have wedges and compensators. It is the same problem with the ships that Honor used without a compensator nor wedge. At 150G they would be crushed like the plane that crashed into the Pentagon. Compensators effectively reduce the structural effect on ships to zero. While for Honor she had a 5G interior grav plated effect, that wouldn't prevent the ship from experiencing the full 200+G effects. If ships can ignore 200+ G effects they should be able to land on planets without damaging themselves. If Ghost rider probes can ignore 5000-15000 G effects, artillery shells electronics can for a few tenths of a second. Maybe solid state electronics could survive. Any probe would be crushed with each maneuver. Ghost rider probes are not armoured.

So if they don't have compensators how do they survive being crushed by the Gees?

For once you've actually got a reasonable question.

The way the "impeller drive" is described, everything inside the effect volume ought to be in an effective zero G environment. Either that or the gravitational gradient should rip everything to rather small shreds, similarly to what happens to something that gets too close to a black hole, or on a smaller scale, anything in a close enough orbit to be tidally locked.

Since our physics prejudices seem to like continuous functions, it's more likely to be the latter. The "compensator," then, smooths out the gravitational gradient within a small part of the effect volume and provides a 1G gravitational gradient as a benefit.

That leaves one slight, barely discernible problem. If the compensator fails, everything should be ripped apart. Humans should not be crushed to jelly, unless by jelly is meant a fog of dispersed cellular components.

So I suspect the basic answer is that the compensator that's used on a missile or a Ghost Rider drone trades off the amount of compensation it can do against the effect volume. That particular compensator technology can't be scaled up to larger volumes, like, for example, a pinnace or a LAC.

Which, of course, suggests that the compensation curves ought to have a third power in there somewhere to represent volume.

Of course, instead of the third power, it's raised to the plot power.