mozartbeatle Posted November 6, 2021 Share Posted November 6, 2021 I have the same, or similar enough problem to @TaintedLion. I was previously able to get many un-upgraded (no J2s, no 1973 H1's) Saturn 1b's into low orbit on JNSQ. However, since the SLA nose cones were added it has been impossible even with the strictest adherence to the wiki guide. Just to confirm, I spent the last hour or two testing it in a fresh install with just BDB, JNSQ, and Mechjeb. My guess (acknowledging I know very little about how a lot of this works in the back end) is that the nose cone is affecting the drag characteristics whether or not it is activated. I was able to restore previous functionality by changing a word in the SLA config files part switch module, switching "affectDragCubes=True" to "False". Since I dont make much use of the nose cone so I've just been using that as a fix. I don't know anything though, so I might be super wrong about the source of the issue. Something else I also was able to confirm from my previous comment in the fresh install, is that the heatshield currently doesn't do much to prevent the Apollo crew cabin from heating. It can be difficult to prevent it from exploding at Mun return velocity. Also unrelated and sorta random but the Kh-7 service module doesn't have a waterfall plume. Quote Link to comment Share on other sites More sharing options...
Pappystein Posted November 6, 2021 Share Posted November 6, 2021 (edited) @TaintedLion@mozartbeatle Ok, so I have NEVER had luck with Mechjeb PVG. I don't use it it sucks. I used the classic assent profile in a build HEAVIER than you guys are dealing with for three reasons 1) I have a Hypergolic SM and SM engine (this gives me about +50dV over you but on the flip side it is a much lower TWR at takeoff and in space!) 2) I didn't use the amazing milkstool. In fact I removed it completely for the purposes of these tests (to eliminate anything it could add directly as a part) 3) I carried the Blk IV payload into orbit as you will see in the pictures. At 80km I had to shut off the Ascent guidance because it was commanding the rocket to crash back to Kerbin. I suggest this has nothing to do with the mod but rather has everything to do with Mechjeb. Mechjeb prioritized getting up to speed more than it did climbing even though "turn end altitude" was set at the 200km my orbit was set to. I ended up in a 277 x 161km orbit with plenty of fuel to de-orbit. In short, as the dev team is pushing these rockets closer and closer to reality, Mechjeb is having more and more problems with it. Spoiler Here is where things are still going good: And now they are not so much. Had to manually fly for a measly 45 seconds with a near-vertical AOA (80 degrees so 10 degrees nose forward) As you can see, all fine again (notice my flight path in the Ascent Editor... not like it should be) In orbit fine Edited November 6, 2021 by Pappystein Quote Link to comment Share on other sites More sharing options...
CDSlice Posted November 6, 2021 Share Posted November 6, 2021 I have always had trouble getting Mechjeb to work for rocket ascents in JNSQ, even with stock parts it tends to do weird stuff like not getting out of the atmosphere before going horizontal and burning up. I only use it for creating maneuvers and rendezvous/docking since it’s good at that and I’m too lazy to do it all the time. Quote Link to comment Share on other sites More sharing options...
Pappystein Posted November 6, 2021 Share Posted November 6, 2021 3 minutes ago, CDSlice said: I have always had trouble getting Mechjeb to work for rocket ascents in JNSQ, even with stock parts it tends to do weird stuff like not getting out of the atmosphere before going horizontal and burning up. I only use it for creating maneuvers and rendezvous/docking since it’s good at that and I’m too lazy to do it all the time. If you are using "standard" settings do this. Open the Ascent Path Editor... and turn off AUTOMATIC ALTITUDE TURN Then manually set your "Turn End Altitude:" to between 0 and 50km below your ideal Altitude for orbit... so long as the turn end is well above Atmosphere you are golden JNSQ the minimum you can set the end turn altitude is about 95km (I typically go for 150 or 200 as you see here the Automatic part assumes Stock KSP and forces Mechjeb to end the turn at 60km... regardless of if you are in atmo or not. Quote Link to comment Share on other sites More sharing options...
Adam-Kerman Posted November 6, 2021 Share Posted November 6, 2021 (edited) this is what i use and it works.. JNSQ - 150x125 Orbit (with a 5 ton Linus Weight) Edited November 6, 2021 by Adam-Kerman Quote Link to comment Share on other sites More sharing options...
Pappystein Posted November 6, 2021 Share Posted November 6, 2021 27 minutes ago, Adam-Kerman said: this is what i use and it works.. JNSQ - 150x125 Orbit (with a 5 ton Linus Weight) Confirmed, it worked for me. I dis-engaged autopilot on J2 burn out. Grabbed my payload, flipped and burned for Apoapsis until the PE was 120km with the SPS motor: CRAP was using the 1973 H-1 engines. Aside from that everything was as described. FULL HEAT SHIELD, Blk IV full up payload with RCS and CADS dockingport. *GUESS for Taintedlion.* You have a Life Support mod. It is adding weight. :shrugstar: Quote Link to comment Share on other sites More sharing options...
Machinique Posted November 6, 2021 Share Posted November 6, 2021 (edited) While there are significant issues with the LM-S landing site that requires abandoning the base (i.e., shouldn't have landed on towards the bottom of a hill), I feel like this is a good proof of concept for LM constructed bases. My next questions are a.) how to build LESA and successfully get a Molab tractor from the top of the lander to the ground, and b.) what to do for an unmanned supply vehicle? A Saturn 1B and a cargo LM can land ~2.5 - 3 tons on the munar surface, which is good enough for supplies and scientific equipment, but insufficient to land new modules or construction materials. ETS and plenty of rocket designs would work, but I want to do this in a semi-roleplay fashion with only the rockets available in the early 70s. Edited November 6, 2021 by Machinique Quote Link to comment Share on other sites More sharing options...
OrbitalManeuvers Posted November 6, 2021 Share Posted November 6, 2021 14 hours ago, TaintedLion said: Okay here you go. https://imgur.com/a/6kBoOGd Alright my friend, I hope something here proves helpful, somehow. First, I suck at this stuff (this is Rule 1 which I will refer to often). So if it works for me it's gotta work for others. My build looks similar, I actually have lower TWR for some reason. You'll notice due to Rule 1, I forgot the S-IVB IU. Also, notice my numbers are with the (incomplete) launch stand detached, as KER shows quite different numbers when it's attached. Spoiler Here's a raw screencap video of the ascent to orbit, including the PVG setup. Launch stand unfinished obviously. This is unedited real time so it's long. Spoiler tl;dr/ihatepvg: PVG nails this flight in a way that would be very difficult to replicate by hand. Watch the Ap/Pe in the last 60 seconds of the video. That said, these are some PVG Truths for me, on my system, almost exclusively based on Friznit-approved BDB builds and variations thereof: - PVG sucks for some rockets - PVG is perfect for some rockets - PVG is extremely sensitive to TWR throughout all stages - too high TWR on upper stages makes PVG less efficient (higher Ap/higher final angle) When PVG does suck for me, I use Classic, and manipulate the Turn end altitude while getting close to Ap and then I drive the Final flight path angle slider to emulate what PVG should have done. I can usually hit my Ap, and have a tiny circularization burn, but it's definitely doing it by hand which is icky. Quote Link to comment Share on other sites More sharing options...
Zorg Posted November 6, 2021 Share Posted November 6, 2021 (edited) 4 hours ago, Pappystein said: Ok, so I have NEVER had luck with Mechjeb PVG. I don't use it it sucks. In short, as the dev team is pushing these rockets closer and closer to reality, Mechjeb is having more and more problems with it. I havent tested the new Saturn I/IB, I guess I should soon and see if anything is up. But I will say that PVG is developed for realism overhaul so more realistically behaving BDB rockets shouldnt be a problem. The vast majority of PVG problems are user error and sometimes craft error, either in the build or in the parts themselves. It sometimes isnt straightforward yes but it is a fantastic implementation of closed loop guidance in KSP but it does need to be deployed appropriately. ps. the small scale of the system (2.7x vs 11.whatever for realscale) also makes PVG behaviour a bit odd sometimes for higher twr upper stages though rarely unusually so. Edited November 6, 2021 by Zorg Quote Link to comment Share on other sites More sharing options...
mozartbeatle Posted November 6, 2021 Share Posted November 6, 2021 @Adam-Kerman I'm not saying it's impossible to get into orbit with the Saturn 1b in general, rather it's impossible with a historical Apollo CSM, even cutting weight. I suspect that the issue is with the SLA panels, in which case using a different fairing is an imperfect simulation. @Pappystein The reason I mentioned using Mechjeb was more to establish that I had followed the instructions most previous "S1b is underpowered" posters have been given. I have previous to now never had an issue with getting a CSM/empty S4b into a low (120km) orbit. I ran a few launches of a standard, unupgraded CSM/S1b with your instructions, and your mechjeb settings. It is technically possible to get into orbit when you use the SPS. However, it was my impression that the Saturn 1b was, and should be able to get an orbital configured CSM into low orbit without having to use the SPS. Doing a cursory search it seems every real life CSM/S1b launch did so, at higher inclinations than you launched into. Up to 2 weeks ago when the SLA nose cone switch was added, that is how the BDB S1b operated. The core of what I'm saying is that the performance of the S1b is fine, I just think that there was an (unintended?) issue that popped up when the nose cone was added. I'm no expert at github, but it appears to me the only change made in that commit was to add a b9 switch for the SLA nose cone, so I rule out balancing nerfs. The day it dropped, I noticed an immediate change to the flight characteristics of the CSM/S1b. I ran through several hypothesis before settling, rightly or wrongly, on it being a drag issue. I made sure to check the entire config file of both the hinged and discarding SLA's, and the only change to drag I could see was the single line I mentioned earlier. That line of code should, to my limited knowledge, only kick in when the nose cone of the SLA is active. However, when I changed it to "False" it improved the flight performance of the open topped SLA used with the CSM and allowed me to again achieve a 130km circular orbit at 32 degrees of inclination, with about 25m/s to spare in the S4b. @OrbitalManeuvers (I'm sad you stopped posting videos btw, glad I could be partly cause for a new one) Following your mechjeb inputs I was closest to achieving an orbit without using the SPS. I have a lower TWR than you however, even removing the IU. Are you removing any other weight? When I stage I'm at ~25km altitude with a ~38km Ap compared to you at ~28km altitude with a ~52km Ap. However, though you get me closer to orbit, both you and Pappy are launching into very low inclinations. I would be interested to see how you both fare when going for more historical ones. Quote Link to comment Share on other sites More sharing options...
SpaceFace545 Posted November 6, 2021 Share Posted November 6, 2021 (edited) @CobaltWolf the S-II mount is rotated Edited November 6, 2021 by SpaceFace545 Quote Link to comment Share on other sites More sharing options...
TaintedLion Posted November 6, 2021 Share Posted November 6, 2021 Dunno if anyone noticed this but the IVA for the LEM is facing the wrong way. Quote Link to comment Share on other sites More sharing options...
OrbitalManeuvers Posted November 6, 2021 Share Posted November 6, 2021 2 hours ago, mozartbeatle said: Following your mechjeb inputs I was closest to achieving an orbit without using the SPS. I have a lower TWR than you however, even removing the IU. Are you removing any other weight? When I stage I'm at ~25km altitude with a ~38km Ap compared to you at ~28km altitude with a ~52km Ap. However, though you get me closer to orbit, both you and Pappy are launching into very low inclinations. I would be interested to see how you both fare when going for more historical ones. Good questions. Picture shows the results, here are the changes I made from the previous video/flight: added S-IVB IU, SIVB SRMs down to 2 from 4, heatshield ablator reduced to 200, target alt 130km. Oh, and looks like I'm still using the wrong APS? oops. Spoiler Quote Link to comment Share on other sites More sharing options...
Naeth Kerman Posted November 6, 2021 Share Posted November 6, 2021 1 hour ago, TaintedLion said: Dunno if anyone noticed this but the IVA for the LEM is facing the wrong way. 2 hours ago, SpaceFace545 said: @CobaltWolf the S-II mount is rotated Looks like the dev. branch is borked again. Quote Link to comment Share on other sites More sharing options...
mozartbeatle Posted November 7, 2021 Share Posted November 7, 2021 @OrbitalManeuvers Alright, using your inputs as a starting point, I was able to contrive an inclined orbit at 115km. Though even that took some amount of monopropellent to finish it off. I will concede that it is possible to get a CSM/S4b into very low orbit mostly intact. Thanks for your help with mechjeb. I hate it even more now. I still hold to my earlier paragraph about the SLA nose being wiggy, with it seeming to effect non-capped SLA's. And having thought the S1b was at a sweet spot of underpowered before, I hope it doesn't end up this marginal. But, if this turns out to be the new normal at least I can get into orbit. Thanks again! Quote Link to comment Share on other sites More sharing options...
Zorg Posted November 7, 2021 Share Posted November 7, 2021 10 hours ago, mozartbeatle said: @OrbitalManeuvers Alright, using your inputs as a starting point, I was able to contrive an inclined orbit at 115km. Though even that took some amount of monopropellent to finish it off. I will concede that it is possible to get a CSM/S4b into very low orbit mostly intact. Thanks for your help with mechjeb. I hate it even more now. I still hold to my earlier paragraph about the SLA nose being wiggy, with it seeming to effect non-capped SLA's. And having thought the S1b was at a sweet spot of underpowered before, I hope it doesn't end up this marginal. But, if this turns out to be the new normal at least I can get into orbit. Thanks again! We’ll look into the potential SLA issue. Not had a chance to test yet. Quote Link to comment Share on other sites More sharing options...
TaintedLion Posted November 7, 2021 Share Posted November 7, 2021 16 minutes ago, Zorg said: We’ll look into the potential SLA issue. Not had a chance to test yet. I just changed the SLA file as @mozartbeatle suggested, I am now able to get the CSM/Saturn IB combo into orbit with a decent margain. I know it's supposed to be extremely margainal, but I'll take it lmao. Quote Link to comment Share on other sites More sharing options...
mozartbeatle Posted November 7, 2021 Share Posted November 7, 2021 (edited) @TaintedLion I can confirm the LM IVA is reversed, it only seems to happen when the LM is docked to something. Further I can confirm it's not specific to the Apollo Capsule, or the Apollo docking ports, or specifically modded parts. (I didn't think it would be, just took the chance to check out some parts I don't usually ever use) Also, super minor note, but I just noticed that the Apollo service module navigation lights are reversed, red for starboard in stead of green, etc. (Also I know I bring up a lot of super minor nitpicks, just say the word and I'll stop.) Edited November 7, 2021 by mozartbeatle Clarify misc details, grammer Quote Link to comment Share on other sites More sharing options...
birdog357 Posted November 7, 2021 Share Posted November 7, 2021 On 11/6/2021 at 7:08 AM, mozartbeatle said: I have the same, or similar enough problem to @TaintedLion. I was previously able to get many un-upgraded (no J2s, no 1973 H1's) Saturn 1b's into low orbit on JNSQ. However, since the SLA nose cones were added it has been impossible even with the strictest adherence to the wiki guide. Just to confirm, I spent the last hour or two testing it in a fresh install with just BDB, JNSQ, and Mechjeb. I just noticed this, you say you're trying to launch a non J2 Saturn IB? That would be a Saturn I and should have an S-IV which is smaller and has a sextet of RL-10s. Unless I'm misunderstanding you. Quote Link to comment Share on other sites More sharing options...
ballisticfox0 Posted November 8, 2021 Share Posted November 8, 2021 Little late to the party but the reflective CM is amazing Quote Link to comment Share on other sites More sharing options...
TaintedLion Posted November 8, 2021 Share Posted November 8, 2021 Doing an Apollo 10-style mission. Quote Link to comment Share on other sites More sharing options...
Jcking Posted November 8, 2021 Share Posted November 8, 2021 (edited) 3 hours ago, birdog357 said: I just noticed this, you say you're trying to launch a non J2 Saturn IB? That would be a Saturn I and should have an S-IV which is smaller and has a sextet of RL-10s. Unless I'm misunderstanding you. It probably was meant to be interpreted as J-2S and not J-2s. Edited November 8, 2021 by Jcking Quote Link to comment Share on other sites More sharing options...
Zorg Posted November 8, 2021 Share Posted November 8, 2021 18 hours ago, TaintedLion said: I just changed the SLA file as @mozartbeatle suggested, I am now able to get the CSM/Saturn IB combo into orbit with a decent margain. I know it's supposed to be extremely margainal, but I'll take it lmao. On 11/7/2021 at 5:28 AM, mozartbeatle said: @OrbitalManeuvers Alright, using your inputs as a starting point, I was able to contrive an inclined orbit at 115km. Though even that took some amount of monopropellent to finish it off. I will concede that it is possible to get a CSM/S4b into very low orbit mostly intact. Thanks for your help with mechjeb. I hate it even more now. I still hold to my earlier paragraph about the SLA nose being wiggy, with it seeming to effect non-capped SLA's. And having thought the S1b was at a sweet spot of underpowered before, I hope it doesn't end up this marginal. But, if this turns out to be the new normal at least I can get into orbit. Thanks again! Just want to confirm if this problem only exists with the hinged SLA or the jettisionable panel version as well? 14 hours ago, mozartbeatle said: @TaintedLion I can confirm the LM IVA is reversed, it only seems to happen when the LM is docked to something. Further I can confirm it's not specific to the Apollo Capsule, or the Apollo docking ports, or specifically modded parts. (I didn't think it would be, just took the chance to check out some parts I don't usually ever use) Also, super minor note, but I just noticed that the Apollo service module navigation lights are reversed, red for starboard in stead of green, etc. (Also I know I bring up a lot of super minor nitpicks, just say the word and I'll stop.) We dont know why this is happening. The IVAs are all old ones which needed to be rotated to match the new models and this is done via a custom module in the BDB plugin. It seems to be failing under certain conditions. I need to see if its possible to rebuild the IVA in unity with the correct orientation to begin with for a clean fix. Quote Link to comment Share on other sites More sharing options...
TaintedLion Posted November 8, 2021 Share Posted November 8, 2021 6 hours ago, Zorg said: Just want to confirm if this problem only exists with the hinged SLA or the jettisionable panel version as well? I've only used the jettisonable panel version where I've confirmed the problem exists, don't know about hinged. Quote Link to comment Share on other sites More sharing options...
CobaltWolf Posted November 8, 2021 Author Share Posted November 8, 2021 9 hours ago, Zorg said: We dont know why this is happening. The IVAs are all old ones which needed to be rotated to match the new models and this is done via a custom module in the BDB plugin. It seems to be failing under certain conditions. I need to see if its possible to rebuild the IVA in unity with the correct orientation to begin with for a clean fix. I'd hazard it's a root part issue. Quote Link to comment Share on other sites More sharing options...
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