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[1.12.x] Mark IV Spaceplane System (August 18, 2024)


Nertea

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OOh... looks really good. Sadly, I can't make a SSTO for the life of e (tiny, witha single stock turbojet( however, iave b9 installed, therefore there is the "rebalancing". maybe too heavy. Is there a ratio of Kn of thrust to ton that I should be following?)

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Progress Update:

Progress on the next update is going along really slowly, I don't have any free time or motivation to work on stuff. I wanted to get a few more adapters at least in before updating but it's not going to happen anytime soon. These parts work fine in 0.90 though so I will just be flagging them as compatible for now.

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I've noticed the Large Cargo Bay doesn't seem to have connection nodes on both the inside and outside of each end (similar to the MK2 bays), making it slightly less convenient to build with it. Not the end of the world in anyway, but something to look at. Unless I'm somehow missing something.

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I've noticed the Large Cargo Bay doesn't seem to have connection nodes on both the inside and outside of each end (similar to the MK2 bays), making it slightly less convenient to build with it. Not the end of the world in anyway, but something to look at. Unless I'm somehow missing something.

They used to mess with FAR, so they got removed. It's not at all hard to put things into the bays at any rate.

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@Beachernaut, the Mk4 parts are very sensitive to CoL being out of place. I'm not entirely sure why this is.

On the bright side I think I just made my first working 2.5m carrying SSTO with these parts. Currently rated for 10 tons.

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first mod for me to install on my new game

yeah no. This is about the 6th mod for me. The rest of Nertea's stuff comes before it. :P Mostly because i do so few cargo SSTOs.

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PROGRESS UPDATE: as per my usual initial design attempts, I was short on fuel, and it likes to fly tail-first on reentry. Gonna have to try and fix that. I need to pile on more fuel and more thrust. More wingspan might also be in order with the increase in mass.

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I guess I should rephrase that. I have a successful MK4 SSTO that is capable of 30+ tons to orbit. However it always goes into a spin between 40 and 20km on reentry. I've always been able to recover and land, but haven't been able to fix the reentry issue. Moving COM forward enough that it is incapable of level flight still results in reentry instability.

Not really a problem since I know I can recover. Though it's always done this, I've probably compounded the issue by modifying the lift ratings on the wings in an attempt to keep part count down. Things get slow when I enter physics range of my 400+ part station, with my 200 part SSTO.

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In the past I've had the things be very flip-happy on takeoff (as in, do a backflip soon as I clear the runway) and this latest one likes to reenter tail-first (which is a problem since even empty its TWR is <1 unless the jets are spooled up to 100% which only happens when ur moving @ 1km/s). I think I might go back to the drawing board since it isn't really fantastic.

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I saw the title and was hoping for a revival of TouhouTorpedo's MK-IV system. Although this isn't the same I do like it. I certainly like the great amount of diversity in the parts for this more than TouhouTorpedo's pack.

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Not sure why, but it seems impossible for me to make an SSTO with MKIV parts that doesn't flop on reentry. Could be that I'm just bad with spaceplanes, but I can make them with MK2 and 3 that have no trouble on reentry.
@Beachernaut, the Mk4 parts are very sensitive to CoL being out of place. I'm not entirely sure why this is.

It's the intakes. I haven't used this mod in a while but i just found out about the intakes that were added while helping out in the Questions forum. Intakes have drag, Intakes ahead of the Center of Mass will drag the front end around to the back. I don't use stock aero, but I'm certain they are in a really bad place for FAR. You might try using the cockpit from Version 1.1.0 of this mod (pictured on the OP), I bet it works a lot better.

Sorry to be the bearer of bad news Nereta, I know you work hard on this.

Edited by Alshain
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It's the intakes. I haven't used this mod in a while but i just found out about the intakes that were added while helping out in the Questions forum. Intakes have drag, Intakes ahead of the Center of Mass will drag the front end around to the back. I don't use stock aero, but I'm certain they are in a really bad place for FAR. You might try using the cockpit from Version 1.1.0 of this mod, I bet it works a lot better.

Sorry to be the bearer of bad news Nereta, I know you work hard on this.

So the entire cockpit is being treated as a massive (albeit inefficient) intake. That would explain a lot. Do we think that will no longer be an issue with the aero remodel or is that aspect of the game unlikely to change?

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So the entire cockpit is being treated as a massive (albeit inefficient) intake. That would explain a lot. Do we think that will no longer be an issue with the aero remodel or is that aspect of the game unlikely to change?

I have no idea, but if the aero remodel is closer to real aerodynamics, in theory it would be worse.

Imagine a model plane, you tie a string to it's center of mass and hang it from the ceiling. It sits level. Now imagine you tied another string to the nose, this string will represent drag force. Pull it back toward the rear of the plane and what happens? The plane flips upside down. Rockets are no different, real aerodynamics require rockets to have fairings or the become unstable due to the massive drag that flat surfaces would cause. Without a fairing they would get flipped just like the plane.

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I have no idea, but if the aero remodel is closer to real aerodynamics, in theory it would be worse.

Imagine a model plane, you tie a string to it's center of mass and hang it from the ceiling. It sits level. Now imagine you tied another string to the nose, this string will represent drag force. Pull it back toward the rear of the plane and what happens? The plane flips upside down. Rockets are no different, real aerodynamics require rockets to have fairings or the become unstable due to the massive drag that flat surfaces would cause. Without a fairing they would get flipped just like the plane.

Would small intakes (relative the overall cross-sectional area) be able to induce that much force?

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Would small intakes (relative the overall cross-sectional area) be able to induce that much force?

I'm not an expert on this, I have a very functional understanding of aerodynamics. I would imagine, functionally, that the further the drag was from the center of mass, the more impact it would have. That's essentially how a lever works, if the effort is near the fulcrum it's not going to lift the load as well as if it were further from the fulcrum (it would require MORE effort). So following that logic, if the drag is closer to the center of mass (in front) it's not going to flip the plane as easily as if it were further from it. If it is behind the center of mass, it's not going to flip it at all. The problem is, the cockpit is usually far from it.

Edited by Alshain
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Alshain's got the right idea -- pitching moments (all moments) are force times a distance (I'm using the language imprecisely, since it's really all vectors and pseudovectors, but in simple cases that's what it boils down to), and the cockpit has a long lever arm from the center of mass, so its effective pitching moment can be very high. Increasing the tail stabilizer surface area might improve stability by increasing the stabilizing moment at the rear, at the cost of increased drag overall. I also saw a craft somewhere in this thread with a bunch of intakes along the horizontal stabilizer (echoing Thunderbird 2's design), which would again add drag behind the CM and improve stability.

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For reference, this is the guy I was trying to help. You can see from his pictures his shuttle is pretty typical. If not for the intakes, I'm sure it would fly.

It also brings up another less severe issue with the intakes though. With them permanently affixed to the cockpit, you don't really have the option of building a space shuttle using these parts. I mean, you can but if you were to mimic the NASA shuttle, you don't need intakes at all. My personal opinion is that intakes should always be separate parts.

Nertea, To fix this you could put a flat end on the cockpit with attachment nodes where the intakes are now. Then make the intake a separate piece. Finally make a new aerodynamic part that would attach in the same place and make it look like the 1.1.0 version of this cockpit (the one in your imgur album). This would let the player choose what they need without compromise really anywhere.

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WELL BALLS.

Nertea, To fix this you could put a flat end on the cockpit with attachment nodes where the intakes are now. Then make the intake a separate piece. Finally make a new aerodynamic part that would attach in the same place and make it look like the 1.1.0 version of this cockpit (the one in your imgur album). This would let the player choose what they need without compromise really anywhere.

Stated objective never to do this.... makes otherwise useless single-use pieces. I'll just revert to the old version of the cockpit, and maybe offer the other one separately as an alternate download. Good thing I kept the old model.

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WELL BALLS.

Stated objective never to do this.... makes otherwise useless single-use pieces. I'll just revert to the old version of the cockpit, and maybe offer the other one separately as an alternate download. Good thing I kept the old model.

Oh, well I thought they were useful in stock aero. I wasn't sure, I didn't want to break their fun. But yeah, it's your call.

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