darthvader15001 Posted July 22, 2022 Share Posted July 22, 2022 (edited) The rules are simple: whoever gets to orbit with the lowest TWR on all stages combined wins Leaderboard: @AeroGav TWR: 0.20 P.S. this is my first challenge, don't judge P.S. 2: there isn't a badge because I'm terrible at photoshopping/creating images Edited August 28, 2022 by darthvader15001 Link to comment Share on other sites More sharing options...
linuxgurugamer Posted July 22, 2022 Share Posted July 22, 2022 (edited) 1 hour ago, darthvader15001 said: thread will close on 7/27/22 Why so short? Also, you do know that TWR changes as fuel is burned off. So how and when should TWR be calculated? It’s easy to build a rocket with an initial TWR of less than 1, which can stroll get to orbit on a single stage. another thing, are you allowing mods? Edited July 22, 2022 by linuxgurugamer Link to comment Share on other sites More sharing options...
darthvader15001 Posted July 22, 2022 Author Share Posted July 22, 2022 1 hour ago, linuxgurugamer said: Why so short? This challenge will just be a short experiment with challenge-making as it’s my first challenge. 1 hour ago, linuxgurugamer said: Also, you do know that TWR changes as fuel is burned off. So how and when should TWR be calculated? Right click on all the stages and one of the readouts should be twr also ker or mj might have stuff to calculate twr. If using that staging bar thingy, just combine the twrs. and yes mods are allowed, but no cheats like hyperedit or alt f12 Sorry for being unclear in the op Link to comment Share on other sites More sharing options...
linuxgurugamer Posted July 22, 2022 Share Posted July 22, 2022 Again, TWR at launch? As I said, it's easy to make a vessel with very low starting TWR get to orbit without cheats. I look forward to your learning from this challenge Link to comment Share on other sites More sharing options...
jimmymcgoochie Posted July 22, 2022 Share Posted July 22, 2022 (edited) I feel obliged to point out that jet engines exist and are a common way to get to orbit with an initial TWR well below 1. There are also motors and propellers which technically have no TWR at all since the game can’t calculate them, which could be used to artificially reduce the average TWR for a spaceplane. I’m sure I’ve heard of someone using only propellers and ion thrusters to fly an SSTO to Kerbin orbit using some serious physics exploits. Edited July 22, 2022 by jimmymcgoochie Link to comment Share on other sites More sharing options...
darthvader15001 Posted July 23, 2022 Author Share Posted July 23, 2022 ok then, jet engines and anything in the robotics section are banned. and sorry that no one likes this challenge, I'm new to the forums and this is my first challenge again, sorry for the unclear rules Link to comment Share on other sites More sharing options...
Vanamonde Posted July 23, 2022 Share Posted July 23, 2022 We can close this thread if you like, but why not give people some time to try it? Link to comment Share on other sites More sharing options...
camacju Posted July 23, 2022 Share Posted July 23, 2022 13 hours ago, jimmymcgoochie said: I’m sure I’ve heard of someone using only propellers and ion thrusters to fly an SSTO to Kerbin orbit using some serious physics exploits. OndrikB and moar ssto produced a very nice video showcasing a craft like this. Link to comment Share on other sites More sharing options...
OJT Posted July 23, 2022 Share Posted July 23, 2022 6 hours ago, camacju said: OndrikB and moar ssto produced a very nice video showcasing a craft like this. Like, I think I am pretty decent at the game, and then I see stuff like this and think to myself "What am I even doing?" This is mindbreaking Link to comment Share on other sites More sharing options...
darthvader15001 Posted July 24, 2022 Author Share Posted July 24, 2022 10 hours ago, OJT said: This is mindbreaking Ikr Link to comment Share on other sites More sharing options...
darthvader15001 Posted August 23, 2022 Author Share Posted August 23, 2022 (edited) I will not follow this thread anymore as it is not active and I have another challenge coming soon. Edited August 23, 2022 by darthvader15001 I not A Link to comment Share on other sites More sharing options...
AeroGav Posted August 28, 2022 Share Posted August 28, 2022 I don't play KSP that often anymore and only saw the thread yesterday. So here is a belated entry. Ladies and Gentlemen, I present the Sloth Ray. https://www.dropbox.com/s/brtkt4ejf8t10ft/Sloth Ray.craft?dl=0 It has 9 Seats and weighs just under 60 Tons. It has three Nervs, One Rapier (only operates in airbreathing mode), and a Panther. Action Group 1 deploys some elevons that push the nose down a few degrees to stop it climbing above altitudes where the jet engines can work, before we're good and ready. Action Group 3 retracts said same flaps. Action group 5 toggles the nukes. It needs those to get though mach 1. Action group 9 toggles the afterburner on the Panther. The TWR that appears on the stock game staging indicators show the following : Airbreathing Stage TWR 0.20 At 20km altitude, the NERV stage reports a TWR of 0.24, getting into the dangerously sporty territory. Of course with the jet engines, the static thrust rating here is highly misleading. Their output falls with altitude, increases with velocity (up to a point) then fall off again as you get faster still. This is what Kerbal wind tunnel says about the air breathing stage. https://imgur.com/ttXElmK https://imgur.com/IaM1wcQ https://imgur.com/pLj7nqo Flight details hidden in spoiler .. Spoiler So in practice, we get up to about 10km and our TWR is down to 0.15. We continue to accelerate slowly but more than 70% of our thrust is being swallowed by drag . So I activate the NERVs and let it climb to about 13km, then nose over to a shallow dive. This gets us through the sound barrier. In the next screenshot we're just about going fast enough that the aircraft can gain energy without the help of the NERVs.. https://imgur.com/q0qq4Ws by mach 2, the Panthers are coming on strong and our thrust to drag ratio remains decent https://imgur.com/MXJCxza This happy state of affairs lasts to around 1000 m/s, the Rapier coming on song at about the same rate the Panther, past its peak, fades. https://imgur.com/hdeZpez At this point, although technically still accelerating our fuel gauge is moving faster than the speedo. So I activate nukes. I keep the nose down trim in until our total thrust falls below 250kN, at which point I figure the drag penalty from flying this low outweighs what we're getting out of the airbreathing rapier. So i hit action group 3 to retract the nose down elevons and we bob up into the upper atmosphere like a champagne cork. Our lift to drag ratio improves to 3.2 to 1 which is decent for hypersonic flight. Our TWR is 0.35 to 1 instead of the 0.24 to 1 predicted in SPH hanger, because of the fuel already used getting up to mach 4. https://imgur.com/X7cSa5x In another 2 and a half to three minutes , we're in orbit. Incidentally, I found out this thing can land on Duna. https://imgur.com/h6PLj2E https://www.dropbox.com/s/7n9fibg2a9cb1ep/FINAL.sfs?dl=0 Here's a save file if you want to land it yourself. Remember to put RCS on. "K" key fires the ventral thrusters which help us touch down slower. Space bar opens the drag chutes which can help it stay straight on the rollout. The biggest danger is getting sideways and flipping over. https://imgur.com/5YuZTmc Link to comment Share on other sites More sharing options...
darthvader15001 Posted August 28, 2022 Author Share Posted August 28, 2022 Nice entry @AeroGav, But I won’t be maintaining this thread after this, as I have a new, way better challenge up my sleeves… Link to comment Share on other sites More sharing options...
Curveball Anders Posted August 28, 2022 Share Posted August 28, 2022 Thread locked at OP's request Link to comment Share on other sites More sharing options...
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