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Marcelo Silveira

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  1. You mean these ones: https://github.com/friznit/Unofficial-BDB-Wiki/wiki/Atlas-Payload-Performance 1.1 is pretty close to the ideal TWR after skirt separation. @dababykerman , if you need more Δv, you can jettison it earlier (that's why I added a line at 0.8 G in the charts) In 2.5x, you need around 5000 m/s to reach orbit, 2.7x will need a bit more than that Δv. So, theoretically, an Atlas LV-3A will launch 2.050 t with a TWR of 1 after skirt jettison while at 0.8 TWR it can launch 2.350 t.
  2. If the Isp and mass fraction ratios in both cases are close, then ther won't be a major difference between the calculated and actual capabilities.
  3. Thanks for that info, this will be helpful when calibrating the model. Total Δv used would be even better The charts are scale agnostic, Δv is Δv regardless of scale. They only calculate how much Δv your rocket is expected to deliver, the total Δv used is the sum of losses (steering, gravity and drag losses) and the Δv applied to the payload (in stock, you need around 3400m/s to orbit and 5000m/s in 2.5x) . You can define a Δv efficiency as how much of the rocket's Δv is applied to the payload (the speed you get at the navball) and that depends on launch profile, TWR, and whatnot and BOY oh BOY oh BOY that gets complicated quickly! Those charts really are a "consider a cow a sphere" kinda of thing In fact, one could make a similar chart to get the optimal launch profile parameters for a given payload mass and required Δv. Do I know how to make that? pfftt, dunno ¯\_(ツ)_/¯ . Do I wanna try it anyway? heheheh, nah. Too much GNC for me
  4. eeyup, once I have some time to play KSP I'll do one for S-1D. I'm also working (slowly but surely) on a Atlas CELV version as well. It's already in the unofficial wiki, I just messed up the link on the forum
  5. Now that the Atlas booster skirt has a module to decouple it at a specified TWR, I updated the Δv maps on the wiki. Now the Δv is shown as a function of payload mass (including upper stage) and TWR at booster skirt jettison instead of payload mass and propellant burned by sustainer phase. The new maps are more straightforward to use. (well, at least they are intended to be) Just take your payload mass and desired Δv and find "at what G should I jettison the skirt" But they might be a bit more complicated to understand though (see spoiler for why). Some feedback would be nice
  6. Welp, I've been away from ksp quite a while but I'm back. Nice work adding an auto jettison module to the Atlas booster skirt, that got me thinking "those Δv maps would be very handy if they were rearranged to show TWR at skirt jettison instead of fuel used by sustainer fuel ..." Vertical axis shows the TWR at booster skirt jettison, black dotted horizontal lines show the TWR after booster skirt jettison.
  7. I checked right now, they are up to date regarding the engines' thrust and Isp. Regarding the mass... I'm not sure... did the masses change at some point? The charts with upper stages might not be valid anymore because there were some changes to many upper stages.
  8. If you want to be EVEN MORE precise, there are some charts in the wiki showing the Atlas performances. There is also a manual on how to use those because a stage and half rocket can be quite tricky to calculate the Δv https://github.com/CobaltWolf/Bluedog-Design-Bureau/wiki/Atlas-Payload-Performance I think they have been updated after the engine balance in BDB 1.6
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