Nittany Tiger

I check that file and it has FOR in place of NEEDS, so that might be the issue. However, haven't tested KKS in play with the fixes. Also, the FOR to NEEDS syntax fix needs to be applied to all of the configs that show up in Module Manager errors.

@eggrobin I think I meant plotting and maneuver frames when I said prediction and planning frames respectively. Anyway, thanks for the response. I'll probably try not staging those tanks until after the burn and also performing the burn in the ECI frame. Hopefully the latter that fixes the problem of the wildly-moving maneuver node marker on the navball. Also, started using NASA's GMAT to plan trajectories with my RSS + Principia save. Real physics model calls for the real tools.

Hey everyone. Happy New Year. Been busy with GMAT. I finally got it to find a possible opposition class trajectory that's a dark-side flyby. Took trial and error, and I wish I had the optimizer, but I made do. What I ended up doing was placing Ares at Venus, using numbers from the book to construct the equation of the hyperbolic trajectory, and then using GMAT to first make some initial guesses on unknown variables like the hyperbolic flyby RAAN (or LAN), AOP, and inclination such that the first heliocentric elliptical leg intercepts Earth. This meant using backwards propagation. Then I ran GMAT's differential correction solver to get a decent solution varying the AOP and inclination. LAN was kept at 180 degrees in a MJ2000 Ecliptic frame of reference. So my solution for the Earth-Venus leg is as follows (all legs start and end at local true anomalies of zero degrees): Delta V for this maneuver is: I'm sure I can optimize this dv. Solution for the Venus - Mars leg is as follows: Delta V to insert into Martian Orbit is: This is a very high insertion orbit. Definitely not going to aim for a 3333km circular orbit. Entering into the more subtle 354 km x 20296 km orbit (the canon one) would take 2.141 km/s of dv. There are some oddities with the orbits as they transition between reference frames, but I guess the canon trajectory is very much realistic. Question is now is it possible in KSP RSS? I'd say the worst case scenario is that I have to force the planets into whatever epochs they were in IRL. Hopefully, Principia will allow me to get the proper or near-proper epochs just from running time forward in the game using the Principia gravity model. Hoping this last big hurdle to doing this mission is behind me. P.S. So the trajectory drawn in the book is wrong. In fact, the book mentions Ares coming closer to the sun than Venus at one point. So, yeah, can't trust the shape of that trajectory at all. The Earth-Venus ellipse I get is actually more accurate compared to the real trajectory.

Update! Thank you everyone for following this thread over the years of this project. I expected to have it done much sooner. This project isn't dead. I won't let it die until it's finished. I've just had a combination of real life issues and snags in the project slow things down. I thought I was actually near completion, but it turns out that recreating the trajectory in KSP is going to take a lot of work. I could just accept a non-canon trajectory, but I really want to adhere to canon here. I did try to find the trajectory using mathematics with patched conics, but things blew up in difficulty when trying to convert the hyperbolic trajectory equation from a Venus inertial frame to a solar inertial frame. I was hung up on trying to incorporate the movement of Venus around the sun and converting true anomalies between co-ordinate systems. I researched astronavitation and learned a lot though, and I learned how hard it is to find these trajectories analytically. It was also very sobering to not be able to find the equation for the trajectory of the craft in the solar inertial frame while it is near Venus. I did get an implicit equation after weeks of hard and frustrating work, but it was very large and I feel might be erroneous somewhere. Luckily @icedown introduced me to a couple of programs that may help me out. One is a TOT for planning real missions. It's like KSP TOT, but uses the real solar system, not RSS, and it works a little differently from KSP TOT. The other is called GMAT, and this tool looks to be extremely flexible an able to find what I want. It has a learning curve, but I've climbed the majority of it. So, I've been playing with TOT and GMAT after giving up on hand math and trying to get GMAT to find me that opposition-class path to Mars with the dark-side Venus flyby. Hopefully, KSP with RSS and Principia does a good enough job approximating the real motions and interactions of the planets so that what I find in GMAT works in KSP. If not, I'm sure there are options that involve some config file tweaking. I still think the hardest part to come will be the video of this I want to do, if I ever get to that stage. I've never done extensive video editing and machinima. I don't think it'll be a problem for me to learn it and practice it, though.

I personally want to use the realistic one for a video project. DECQ was the only one maintaining a real-to-life Saturn V. The others were going more stockalike since most people seemed to like that, but some of us want realistic-looking craft like the Saturn V for historical recreations or nostalgia.

I'd love to get the files for at least the Saturn V rocket. I don't need the Command Module or Lunar Module. They seem to work for KSP 1.2.2. and 1.3.

No problem. Did you push your early rockets past their MTBF? You might want to go by the MTBF given in the VAB, not at launch, because that's always really high and then decreases during flight. I've used Test Flight in a career mode, but I was able to get to orbit. Here was the rocket that did it. It was done in 1.1.3. Vangard first stage and boosters. AJ-10 second stage. Baby Sergeants with the 11x-3x-1x configuration just like with Juno. Had to do a lot of simulations due to part failures and trajectory optimization, but it worked when the real deal launched. Yes. My own Korolev Cross. Been wanting to get back to RP-0 for a while, but I want to finish Ares first.

Yes, with this mod: It works for preventing LH2 boil-off. It does use electricity, but it's not much. I didn't have issues keeping the pumps operating with no changes to my power generation setup. I thought of modifying the real fuels mod config files to either create some exotic tank type or even break physics by changing the properties of LH2, but I felt using this mod kept things within the realm of realism. It's also the only way I'm getting any LH2 to Mars without it all evaporating into space.

Updates to my Saturn VB and Ares Propulsion Stage. Saturn VB now uses RSRMs to be more accurate to Voyage. Meant weight reduction in the payload. Also reworked the life support system to save weight. External tanks are now silver to better reflect the description in the novel. They also contain more fuel. The entire state contains radiators from the Heat Pump mod to eliminate annoying boil-off.

Guess he's saying his Saturn V hasn't been updated. He has an older release on the forums. Can't recall what version it works for, but it's not 1.2.2 or 1.3.1. I have the older version downloaded. It does load, but it needs work to fix the attachment points and J-2 engine models. It's a stunning model, though, and blows FASA out of the water with the detail. It's why I'm sad it's not being continued. I wanted to use the DECQ Saturn V for my Ares project. Either way, I respect the modder's decision to not further develop the mod.

I hate that since I was looking forward to using this version of the Saturn V. Love the detail of it. Hopefully someone else picks it up and maintains it.

I've hit a snag. I have worked weeks to try and recreate the flight path of Ares in KSP using both RSS with and without Princpia. The main problem is that I can't seem to get a proper trajectory that approaches Venus from the correct vector to allow a dark-side flyby that boosts Ares to Mars. All of the trajectories I can find either through guided trial-and-error and using flyby finding software for KSP always produce a light-side flyby option. I'm not sure what I'm getting wrong to not get the proper Earth-Venus flight path. For reference, here's the flight path given in the book (in Spanish. I can't find an English version, though I could scan my copy of Voyage and post the flight plan there): This represents the Earth-Venus ellipse I typically get: The only ellipse that intercepts Venus has a lower perihelion than the one in the book. I have tried to match the perihelion of my E-V ellipse and I usually get a path that doesn't intercept Venus. This is both in the patched conics model and n-body model. I can say that maybe I should vary my starting inclination, but I feel that varying the normal vector for the burn covers all possible starting inclinations. I'm sure I'm missing something. I think I might end up doing a mathematical and physical analysis to see if the trajectory in Voyage is possible. I've been very tempted to do that, but thought it might be too much work compared to maneuver node trial and error. However, it might be necessary now, and I have some ideas on how to tackle that problem.

I'm trying to fly an opposition-class Mars mission with the Venus flyby occurring during the trip to Mars. If you've ever read Voyage, then you'll know the mission. This is my ship. So I want to burn to inject into an Earth-Venus-Mars trajectory. During the burn, the two silver external tanks get depleted, so I jettison them mid-burn. When I set up the burn, I use either the Earth-Centered Inertial frame, Venus-Centered Inertial Frame, or Mars-Centered Inertial frame. When doing the burn, I use the Earth-Centered Inertial frame. I'm not sure if you have to stick to one reference frame when doing the planning and burning. Would make it hard for me to do this flyby since I need to switch reference frames to see where I need to tweak my flight plan to fly by Venus and intercept Mars. I'm also not certain if you have to set both the flight prediction frame of reference and flight planning frame of reference to the same frame when manipulating a maneuver node or doing a burn. I always see a warning message when those two frames don't match, but when I have the frames match, I sometimes get nonsensical trajectories like burns that never exit Earth's SOI. And for my mission, it has to start on or around March 21st, 1985, and that's why I need to advance the game past RSS's default start date of 1/1/1951. I guess I'll just do what you recommended to get to the date I need and just warp there.

Yeah, I figured the inertial was a fixed vector frame. I assume it's the same as the stock maneuver nodes if you combine it with impulse calculations. I do like the non-intertial tangent vector since it does allow for more efficient burns. What I figured doing was to switch SAS from maneuver node tracking to stability assist when my velocity neared Earth's escape velocity so my ship would not turn wildly trying to chase after a wildly-varying maneuver node. I did think of a possible cause. My burn was 20 minutes, and about 17 minutes in, I would dump empty external tanks to conserve dV. I know that Principia doesn't like mass changes during maneuvers according to the wiki (other than the obvious burning of fuel), so maybe that had something to do with it? It doesn't seem logical to me, though. I bet I could understand that more if I dust off my old classical mechanics books and see what math might be behind Principia. As far as the Hyperedit issues, they're not big deals. I did update, and it didn't fix the issue, but I can work around the issue by just making another save or quicksaving certain ways. I only need Hyperedit to move the game's clock forward to 1985 (and back to March 21st for failed mission attempts), which would take quite a while with time warping (You have to warp 35 years). Warping forward once doesn't seem to make the bug happen, and I could find other ways of moving the clock like editing the save file, so Hyperedit incompatibilities aren't something that's a dealbreaker for me when using this mod. I'm clever enough to work around the bugs.

Last time I clicked "Inertially fixed" for my 20-minute trans-cytherian injection, my craft ended up pitching 60 degrees from prograde when I had it follow the maneuver node marker. I also had an issue where the maneuver node marker would shift wildly when my path would go from elliptical to hyperbolic. This was using body-centric inertial frames of reference. I haven't updated to Chasles yet. Hope that fixes another bug Cesaro created where using Hyperedit to jump ahead in time would somehow cause any craft I launch to be rolled out to the middle of the Altantic, not the launchpad.

Rough month. Also still learning Principia, so TCI took more than one try. Especially annoying when playing RSS at 5 FPS on a 2-year-old laptop. Anyway, more screenshots.

More cool shots from this current mission run: Approaching the Ares Propulsion Module: Natalie York's view of the approaching propulsion stack: Docking: Those silvery tanks do look nice. Also, a blooper. Some bad driving on my part. No broken parts. Just scratches. I'm sure the crew will make Natalie get out there and buff them being the rookie and all.

Started the second full attempt after the updates and changes to the craft. Images here: https://imgur.com/a/DbZhA Some highlights: Also, I really like Principia's target-relative body-centered reference mode. Really makes planning rendezvous easier when you get to understanding it.

I'm finding the target reference frame plot (LVLH@E) super-useful for planning rendezvous. This should be in stock. A little hard to get used to at first, but I find it better than stock close approach markers since this reference frame lets me see how one vessel moves with respect to the other. Means I can tell which direction to adjust a maneuver and potentially figure out the lowest dV approach. The more I use this mod, the more I don't think I can live without it in stock.

TLS base resources are pretty heavy. That's why I switched to using converters. I saved some weight by adding a CO2 scrubber and enough water filtration for three crew. There's no way AFAIK to produce food with TAC LS, so I just packed enough for the trip and some extra. Fuel also added quite a lot of mass, so I ended up removing fuel from the CSM, OMM, and AMM RCS tank. The CSM in Voyage actually is described as having more RCS and less AJ-10 SPS fuel than the Block II that was used to go to the Moon. It's because the SPS is only used to de-orbit after the mission is complete. And thank Thanks. A year on and off working on this and I hope to get a good mission in soon. Going to make another practice attempt today. Should have more dV for the whole trip, and took care of boil-off, though it's not a canon solution to the problem. Furthermore, decided to work on another key craft in the Voyageverse. It's the infamous Apollo-N rocket. Spent a day putting this together, and had some help fitting the long NERVA's mount to the S-IVB tank. Might also put together Skylab Wet Workshop and Moonlab as well.

More updates. Installed real KSC to see how it would work.

Does it not exist in the game? Pad 39A is a Space Shuttle pad. Also, just got this installed. Don't see the Canaveral VAB, but maybe it's being retextured or something. However, do want to show off this cool shot. Saturn VB at LC 39B. Wish the access arm was moveable and I could get the FASA umbilicals to fit in the tower, but otherwise it's pretty cool to see a Saturn VB out on the pad like it would if this was a real life mission.

Made a change to the Ares Propulsion Stack. Changed the design and texture to more match the description in the novel. Also added radiators from the Heat Pump mod to prevent H2 boil-off and separation motors.

Turns out I was wrong about KSP's patched conics having an issue with gravity assists. After discussing it with people in the Principia thread, turns out I can do the flyby proper without Principia. I had some suspicions that it was a bad trajectory, but went with the idea that stock patched conics was wrong. Oh well. Learn something new every day.

@Iskierka I did wonder if my whole trajectory was off before. Seems like it was and it wasn't just bad physics. Might be because I was relying a lot on tools like Flyby Finder and KSP TOT. I did think that it was possible, given a different entry into the Venus SOI, to get a boost from a dark-side flyby. Despite studying physics in college, I have not done much work with planetary navigation, so I'm learning this as I go. It's why I had trouble accepting the conclusion that a flyby should give a craft extra velocity because, as I said before, gravitational fields are conservative and do no net work, and in a two-body problem, you should get no net change in speed in the frame of reference of the large body. The directional changes make a lot of sense to me, being vectors, and that's why I though the only way to get to Mars in an opposition-class approach was either with a light-side flyby of Venus or a trajectory that approaches like this: Forgive the poor quality. I threw this together in five minutes to quickly illustrate my suggestion. Of course, a pericytherian that low might result in a larger trajectory change, but the point is at the right pericytherian, you should get a trajectory like that. So, it is nice to know that KSP's base system does flybys better than I thought.