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[1.12.5] Bluedog Design Bureau - Stockalike Saturn, Apollo, and more! (v1.14.0 "металл" 30/Sep/2024)


CobaltWolf

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As far as the Belle-RNRD nose cone for the GATV is concerned, is it supposed to be jettisoned once the vehicle arrives in orbit? As it currently stands it does not have any separation force at all. If you try to stage it during the ride to orbit while the vehicle is still under acceleration it will get hung up before eventually falling away, potentially causing damage. If you wait until reaching orbit, it does separate cleanly, but with virtually no separation delta-V. I could not find a definitive reference which stated when the shroud was jettisoned, but I think it is a safe assumption that the intention was to get rid of it once out of the atmosphere but before the vehicle reached orbit, in a fashion similar to all other shrouds. It would save weight and improve vehicle performance, and it would eliminate a potential debris hazard for the Gemini vehicle as it approached for docking.  @Rodger

Edited by DaveyJ576
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I know I'm missing something simple. Ksp 1.12.4 and current release of BDB. I've built up a Ranger block 2 stack on an Atlas LV-3/agena-b just like IRL. I can not get the thing to fly. It swaps ends before it's even one booster length off the ground. I built it up from the stock craft files in the download. Yes, the nav ball is pointing up. I'm sure this is a PEBKAC error. What am I doing wrong?

 

Edit: It was something stupid. Fly by wire lost calibration, so it was commanding a full stick throw left down and yaw left.

Edited by birdog357
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50 minutes ago, birdog357 said:

I know I'm missing something simple. Ksp 1.12.4 and current release of BDB. I've built up a Ranger block 2 stack on an Atlas LV-3/agena-b just like IRL. I can not get the thing to fly. It swaps ends before it's even one booster length off the ground. I built it up from the stock craft files in the download. Yes, the nav ball is pointing up. I'm sure this is a PEBKAC error. What am I doing wrong?

The first question that immediately comes to mind is "how quickly are you turning the vehicle?" The second is "do you have stability assist enabled?" Finally, "is the rocket flexing like it doesn't have sufficient auto-struts?"

Early Atlas in particular is not trivial to fly manually, because you have to take the half-stage into account, but it shouldn't be unstable so close to the ground unless you're trying to turn it too quickly.

For a flight profile that should work: normally I wait until 1km above ground before I start turning, and then I turn 1 degree every 200 meters altitude (or, for manual flight, 5 degrees every 1km) until the rocket is 60 degrees above the horizontal. Then it's half that rate of turning (1 degree per 400m, 5 degrees per 2km) until 50 degrees above the horizontal (should happen at 11km altitude). After that, I wait until 15km altitude, and start to turn 2 degrees per kilometer altitude until reaching 40 degrees at 20km altitude. Then, I turn 1 degree per kilometer until reaching 20 degrees at 40km altitude. At that point, you can start thinking about orbital insertion, and your approach will vary depending on the vehicle's specific design (in particular, its upper stage burn duration), but most of the time I reduce to 10 degrees by 50km altitude, 5 degrees by 70km altitude, and then wait until apoapsis is out of the atmosphere before I reduce angle above horizontal to zero. Alternatively, if you're playing at stock scale instead of 2.7x scale (the latter of which is what BDB is balanced for), once you reach 40km altitude you can just burn until your projected apoapsis is where you want it, then coast to orbit and circularize. This general approach works extremely well for the vast majority of rockets, including everything I've tested in BDB except Scout (and I've tested almost every major rocket configuration in BDB by this point).

For early Atlas, auto-jettison of the half-stage engines should typically be set (on the engine shroud) to an acceleration between 3G and 4G, depending on upper stage, payload mass, and required orbital parameters: if your upper stage burn time and/or thrust-to-weight ratio is particularly low and you have sufficient delta-v margins, set the cutoff to a higher acceleration (which allows your first stage to put out more thrust more quickly (giving your upper stage more time to burn), but reduces its delta-v); if your payload mass is particularly high and/or your delta-v margins are otherwise very limited, set the cutoff to a lower acceleration (which allows you to maximize the delta-v of the first stage at the expense of thrust).

If you have very limited delta-v margins and an extremely long upper stage burn time, you'll almost certainly need to adjust the main launch profile so that the first stage (especially prior to half-stage separation, which should occur at as low an acceleration as you can get away with, but almost never lower than 2.5G) spends more of its fuel burning with a partially-upwards vector, and aim for a higher apoapsis than your actual intended parking orbit (this allows the upper stage to burn horizontally for a long time and it eventually falls down from the initial apoapsis to circularize nearer to the atmosphere). This is an advanced technique that's not necessary for canonical payloads included in BDB, and is just about useless if you play mostly-stock and in a stock-scale solar system (unless your upper stage engine is nuclear or ion), but it can be very important in the circumstances I described.

If you're not turning too quickly and you have stability assist enabled, then you've assembled the rocket wrong. If the rocket is flexing, autostrut the big main fuel tank part of the Atlas rocket (the part with the side greebles) to the root part (which should be the probe core) and that should prevent flexing. Regardless of whether the rocket is flexing, double-check that the root part is indeed the probe core. Check staging to ensure that: the sustainer, half-stage, and vernier engines are all ignited simultaneously on the launch pad; the half-stage skirt is jettisoned after first stage engine ignition and before upper stage separation; the Agena engine is only ignited after the Agena decoupler fires; the fairing is either auto-staged at the default altitude or is manually staged at some point after the half-stage skirt separates (for almost all circumstances I recommend just turning off manual staging for it, assuming you're using the Simple Adjustable Fairings one); the payload only separates from the upper stage after the fairing is deployed; and the payload engine only ignites after all of the above. If the rocket still doesn't work, make sure you've attached all nodes properly and not accidentally surface-attached the Agena to the payload or something similar to that, because KSP aerodynamics doesn't care about the shape of the vehicle (unless you're using FAR), it mostly only cares about whether an unoccupied node is pointing forward, or whether any part at all is outside of a fairing/cargo bay. Finally, check that you've used the correct SAF fairing for Ranger: there are a lot of Agena fairings, and not all of them can contain all payloads - a non-Ranger fairing might leave some parts of Ranger clipping outside of the fairing, which will ruin the aerodynamics and could cause flipping (or, at best, it will seriously impair the aerodynamic profile of the vehicle).

EDIT: One final question just occurred to me: did you remember to throttle up before launch?

Edited by septemberWaves
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10 hours ago, DaveyJ576 said:

As far as the Belle-RNRD nose cone for the GATV is concerned, is it supposed to be jettisoned once the vehicle arrives in orbit? As it currently stands it does not have any separation force at all. If you try to stage it during the ride to orbit while the vehicle is still under acceleration it will get hung up before eventually falling away, potentially causing damage. If you wait until reaching orbit, it does separate cleanly, but with virtually no separation delta-V. I could not find a definitive reference which stated when the shroud was jettisoned, but I think it is a safe assumption that the intention was to get rid of it once out of the atmosphere but before the vehicle reached orbit, in a fashion similar to all other shrouds. It would save weight and improve vehicle performance, and it would eliminate a potential debris hazard for the Gemini vehicle as it approached for docking.  @Rodger

It’s quite possible the ejection force is inverted, I’ll have a look 

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7 hours ago, septemberWaves said:

The first question that immediately comes to mind is "how quickly are you turning the vehicle?" The second is "do you have stability assist enabled?" Finally, "is the rocket flexing like it doesn't have sufficient auto-struts?"

Early Atlas in particular is not trivial to fly manually, because you have to take the half-stage into account, but it shouldn't be unstable so close to the ground unless you're trying to turn it too quickly.

For a flight profile that should work: normally I wait until 1km above ground before I start turning, and then I turn 1 degree every 200 meters altitude (or, for manual flight, 5 degrees every 1km) until the rocket is 60 degrees above the horizontal. Then it's half that rate of turning (1 degree per 400m, 5 degrees per 2km) until 50 degrees above the horizontal (should happen at 11km altitude). After that, I wait until 15km altitude, and start to turn 2 degrees per kilometer altitude until reaching 40 degrees at 20km altitude. Then, I turn 1 degree per kilometer until reaching 20 degrees at 40km altitude. At that point, you can start thinking about orbital insertion, and your approach will vary depending on the vehicle's specific design (in particular, its upper stage burn duration), but most of the time I reduce to 10 degrees by 50km altitude, 5 degrees by 70km altitude, and then wait until apoapsis is out of the atmosphere before I reduce angle above horizontal to zero. Alternatively, if you're playing at stock scale instead of 2.7x scale (the latter of which is what BDB is balanced for), once you reach 40km altitude you can just burn until your projected apoapsis is where you want it, then coast to orbit and circularize. This general approach works extremely well for the vast majority of rockets, including everything I've tested in BDB except Scout (and I've tested almost every major rocket configuration in BDB by this point).

For early Atlas, auto-jettison of the half-stage engines should typically be set (on the engine shroud) to an acceleration between 3G and 4G, depending on upper stage, payload mass, and required orbital parameters: if your upper stage burn time and/or thrust-to-weight ratio is particularly low and you have sufficient delta-v margins, set the cutoff to a higher acceleration (which allows your first stage to put out more thrust more quickly (giving your upper stage more time to burn), but reduces its delta-v); if your payload mass is particularly high and/or your delta-v margins are otherwise very limited, set the cutoff to a lower acceleration (which allows you to maximize the delta-v of the first stage at the expense of thrust).

If you have very limited delta-v margins and an extremely long upper stage burn time, you'll almost certainly need to adjust the main launch profile so that the first stage (especially prior to half-stage separation, which should occur at as low an acceleration as you can get away with, but almost never lower than 2.5G) spends more of its fuel burning with a partially-upwards vector, and aim for a higher apoapsis than your actual intended parking orbit (this allows the upper stage to burn horizontally for a long time and it eventually falls down from the initial apoapsis to circularize nearer to the atmosphere). This is an advanced technique that's not necessary for canonical payloads included in BDB, and is just about useless if you play mostly-stock and in a stock-scale solar system (unless your upper stage engine is nuclear or ion), but it can be very important in the circumstances I described.

If you're not turning too quickly and you have stability assist enabled, then you've assembled the rocket wrong. If the rocket is flexing, autostrut the big main fuel tank part of the Atlas rocket (the part with the side greebles) to the root part (which should be the probe core) and that should prevent flexing. Regardless of whether the rocket is flexing, double-check that the root part is indeed the probe core. Check staging to ensure that: the sustainer, half-stage, and vernier engines are all ignited simultaneously on the launch pad; the half-stage skirt is jettisoned after first stage engine ignition and before upper stage separation; the Agena engine is only ignited after the Agena decoupler fires; the fairing is either auto-staged at the default altitude or is manually staged at some point after the half-stage skirt separates (for almost all circumstances I recommend just turning off manual staging for it, assuming you're using the Simple Adjustable Fairings one); the payload only separates from the upper stage after the fairing is deployed; and the payload engine only ignites after all of the above. If the rocket still doesn't work, make sure you've attached all nodes properly and not accidentally surface-attached the Agena to the payload or something similar to that, because KSP aerodynamics doesn't care about the shape of the vehicle (unless you're using FAR), it mostly only cares about whether an unoccupied node is pointing forward, or whether any part at all is outside of a fairing/cargo bay. Finally, check that you've used the correct SAF fairing for Ranger: there are a lot of Agena fairings, and not all of them can contain all payloads - a non-Ranger fairing might leave some parts of Ranger clipping outside of the fairing, which will ruin the aerodynamics and could cause flipping (or, at best, it will seriously impair the aerodynamic profile of the vehicle).

EDIT: One final question just occurred to me: did you remember to throttle up before launch?

The rocket was going into a death spiral as soon as the clamps released. It turns out my stick was out of calibration and commanding full left roll and yaw as well as full forward pitch.

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1 hour ago, birdog357 said:

The rocket was going into a death spiral as soon as the clamps released. It turns out my stick was out of calibration and commanding full left roll and yaw as well as full forward pitch.

That explains it then, glad you figured it out. If you have any further trouble flying Atlas (or any other BDB rocket for that matter (other than Scout, which is a huge pain)), what I wrote out there may help you out.

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On 2/5/2023 at 1:36 PM, DaveyJ576 said:

As far as the Belle-RNRD nose cone for the GATV is concerned, is it supposed to be jettisoned once the vehicle arrives in orbit? As it currently stands it does not have any separation force at all. If you try to stage it during the ride to orbit while the vehicle is still under acceleration it will get hung up before eventually falling away, potentially causing damage. If you wait until reaching orbit, it does separate cleanly, but with virtually no separation delta-V. I could not find a definitive reference which stated when the shroud was jettisoned, but I think it is a safe assumption that the intention was to get rid of it once out of the atmosphere but before the vehicle reached orbit, in a fashion similar to all other shrouds. It would save weight and improve vehicle performance, and it would eliminate a potential debris hazard for the Gemini vehicle as it approached for docking.  @Rodger

I really feel like the docking cone should have a SAF variant

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7 hours ago, mococo said:

install this and it should fix it:

https://drive.google.com/file/d/10zdtxBecBq6KDjLS19GIM4_HnNkzK_mp/view?usp=sharing

lmk Let me know if it doesn't

 

@DaveyJ576the GATV fairing nosecone is fixed on dev now too

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@Rodger I think I found a bug. When using physics warp with the RL-10B-2, the animation gets held up at the point of engine ignition and won't actually ignite. It goes into a repeating loop, constantly playing the engine ignition sound. This is remedied by simply disabling physics warp. I have caught this bug outside of Physics warp a few times too.

Edited by GoldForest
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4 hours ago, CobaltWolf said:

Surveyor "B" Orbiter parts have been added.

Not a lot of info for it, I'm curious what sort of builds people can come up with for greebling it.
The types of experiments it'd include are mentioned in the image below.

pnHravV.png

LLPSjwg.png
uW41kL6.png
Y9Hq09O.png

 

It is indeed hard to find info on it - the only other relevant file other than the slide you posted i have on it is the image below, and it looks nothing like a Surveyor probe. Very nice model!

unknown.png

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5 minutes ago, ra4nd0m said:

Just a note but there are two surveyor probe cores currently displaying on latest dev branch

That's correct - the Orbiter's core has some pretty significant differences (the fuel tanks are nearly double in size, for one). I am... somewhat notoriously lazy when I get parts in game. I did actually put in the effort to change the default names, but the real names/descriptions were definitely not updated.

3 minutes ago, Beccab said:

It is indeed hard to find info on it - the only other relevant file other than the slide you posted i have on it is the image below, and it looks nothing like a Surveyor probe. Very nice model!

Yeah, I have no idea what that thing is... The one I added is mostly just me removing the lander-specific equipment, like the radars, and pieces that would have clipped with the solar panels. The fuel tanks are longer and the structure is slightly different, but other than that it's really just a hypothetical configuration.

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TDj5jss.png

Did a full Surveyor 1 mission today in KSRSS. This mission in particular gets my axial tilt nerve all worked up (well this, and Pioneer 1). Direct ascent in KSRSS with Default inclination means you have to launch at night, and your landing spots are pretty limited if you want both sunlight and comms. Unless I'm wrong, of course.

ANYWAY ... I tucked in the antennas above to make sure they didn't get caught on any power lines during landing. All in all this has always been one of my all time favorite recreation missions, and the new BDB parts are pretty amazing.

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