moogoob Posted June 20, 2016 Share Posted June 20, 2016 After some more drawing board stuff, I got the lander under 0.5 tons without cutting fuel. This one has the same basic concept as the last one, only with a smaller monopropellant supply, less battery, one fewer solar panel and better probe core. Quote Link to comment Share on other sites More sharing options...
fourfa Posted June 20, 2016 Share Posted June 20, 2016 41 minutes ago, moogoob said: After some more drawing board stuff, I got the lander under 0.5 tons without cutting fuel. This one has the same basic concept as the last one, only with a smaller monopropellant supply, less battery, one fewer solar panel and better probe core. How much delta-V is in there? Might have to calculate by hand, I don't think KER or MJ handle RCS well. I wonder what happens to dV with a couple of the 0.005t science instruments... Quote Link to comment Share on other sites More sharing options...
Fearless Son Posted June 20, 2016 Share Posted June 20, 2016 10 hours ago, Vermil said: But towards the end of the test, an important fact was learned. I'm ejecting the stabilizer boom after I've deployed the first parachutes. This is to reduce the risk of it causing damages later. However, the drag chutes and standard chutes that I deploy early are not enough to keep Orpheus directionally stable. It immediately started to tumble. So this has to change. Perhaps the boom will only be ejected after landing? Sounds risky, but with a few separator rockets... That makes me think, did you run into the tumbling issues before or after the chutes reached full deployment? Because I have noticed that keeping stability on an atmospheric lander after the chutes are fully deployed is easy, the hard part is when the craft is still moving at high speed and low pressure before those chutes can get enough control. So you might consider just waiting for the chutes to fully deploy before you eject the boom. Quote Link to comment Share on other sites More sharing options...
moogoob Posted June 20, 2016 Share Posted June 20, 2016 13 minutes ago, fourfa said: How much delta-V is in there? Might have to calculate by hand, I don't think KER or MJ handle RCS well. I wonder what happens to dV with a couple of the 0.005t science instruments... No idea!! Mechjeb was no help as it doesn't consider an RCS port set to "use throttle as forward" or whatever as an engine, and I didn't bother putting an AR-202 case on for that reason. If it helps you eyeball, I had about 5/6ths of the tank left after landing. Quote Link to comment Share on other sites More sharing options...
fourfa Posted June 20, 2016 Share Posted June 20, 2016 @moogoob never mind - I copied it and calculate 1687m/s of delta-V as shown. Losing about 25m/s per instrument Quote Link to comment Share on other sites More sharing options...
moogoob Posted June 20, 2016 Share Posted June 20, 2016 Just now, fourfa said: @moogoob never mind - I copied it and calculate 1687m/s of delta-V as shown. Losing about 25m/s per instrument Cool! Thanks for crunching the math and satisfying my curiosity. Quote Link to comment Share on other sites More sharing options...
Vermil Posted June 20, 2016 Share Posted June 20, 2016 (edited) 14 hours ago, Fearless Son said: That makes me think, did you run into the tumbling issues before or after the chutes reached full deployment? Because I have noticed that keeping stability on an atmospheric lander after the chutes are fully deployed is easy, the hard part is when the craft is still moving at high speed and low pressure before those chutes can get enough control. So you might consider just waiting for the chutes to fully deploy before you eject the boom. There's a lot of light and draggy structures at the bottom of the rocket. The chutes don't stand a chance. That's four drag chutes and four normal chutes. As you can see, the XL chutes are still red, I can't deploy them at that this moment. But of course the plan is that the Orpheus will hang stable in the parachutes. Edited June 21, 2016 by Vermil Quote Link to comment Share on other sites More sharing options...
Fengist Posted June 20, 2016 Share Posted June 20, 2016 Played with a few boats... and a submarine Quote Link to comment Share on other sites More sharing options...
fourfa Posted June 20, 2016 Share Posted June 20, 2016 (edited) 52 minutes ago, moogoob said: Cool! Thanks for crunching the math and satisfying my curiosity. Turns out (after doing the math by hand), RCS Build Aid computes it. Thirdly, I make TWR to be 4.3 in Kerbin orbit. This thing can land and return to orbit of the smaller bodies - Eeloo through Gilly. I never realized it, but a single place-anywhere thruster is actually a lot of thrust relative to a tiny probe like this. Have a look at the 0.625m or 1.25m RCS tanks (better weight ratio) - you can actually use a ton more fuel if you want. And I know you said monoprop only, but I got curious about the Ant LFO engine (same thrust, less mass, better ISP) as well as probe cores with reaction torque and ended up with this: 3807m/s dV, and can land and re-orbit any body except Eve, Tylo, Kerbin, and Laythe! Edited June 20, 2016 by fourfa Quote Link to comment Share on other sites More sharing options...
moogoob Posted June 20, 2016 Share Posted June 20, 2016 10 minutes ago, fourfa said: Turns out (after doing the math by hand), RCS Build Aid computes it. Thirdly, I make TWR to be 4.3 in Kerbin orbit. This thing can land and return to orbit of the smaller bodies - Eeloo through Gilly. I never realized it, but a single place-anywhere thruster is actually a lot of thrust relative to a tiny probe like this. Have a look at the 0.625m or 1.25m RCS tanks (better weight ratio) - you can actually use a ton more fuel if you want. And I know you said monoprop only, but I got curious about the Ant LFO engine (same thrust, less mass, better ISP) as well as probe cores with reaction torque and ended up with this: 3807m/s dV, and can land and re-orbit any body except Eve, Tylo, Kerbin, and Laythe! nice! How heavy? Quote Link to comment Share on other sites More sharing options...
fourfa Posted June 20, 2016 Share Posted June 20, 2016 847kg. Throw a mini docking port on it, all the small science instruments, and you can still re-orbit the planets I listed and recover experiments at 100% value. Quote Link to comment Share on other sites More sharing options...
Triop Posted June 20, 2016 Share Posted June 20, 2016 (edited) Today, rookie training . . . I love how they always scream . . . Edited June 20, 2016 by Triop Quote Link to comment Share on other sites More sharing options...
Vermil Posted June 20, 2016 Share Posted June 20, 2016 (edited) I don't recognize the KSP physics any more, in 1.1. It's not just the wheels. Everything's affected by strange over-steered oscillations. I can't trust that my old rockets will be launchable any longer. Many, like the Magma superlifter here, will not, until it's thoroughly worked over to work with the Unity 5 physics. It's just as if the physics simulation is less accurate. Same with orbits and trajectories, they don't fine-adjust or stay stable. And soon after I made a successful testlanding the dam client crashed again... Even though it was the 32-bit client. I'm in a bad mood now. Edited June 20, 2016 by Vermil Quote Link to comment Share on other sites More sharing options...
Combatsmithen Posted June 20, 2016 Share Posted June 20, 2016 I made another realism overhaul video! Quote Link to comment Share on other sites More sharing options...
AeroAviation Posted June 20, 2016 Share Posted June 20, 2016 Eve Surface probe successfully touched down on Eve (not without cutting it close to overheating in atmospheric entry) Quote Link to comment Share on other sites More sharing options...
Dispatcher Posted June 21, 2016 Share Posted June 21, 2016 3 hours ago, Vermil said: Your problem is: not enough boosters! Seriously, good luck in your future attempts. That looks like it was a lot of work. Quote Link to comment Share on other sites More sharing options...
TheSealBrigade Posted June 21, 2016 Share Posted June 21, 2016 I was doing a routine "tech check", as required by the Omega Exploration Program. I managed to catch a beautiful shot of Sonnah! (From the New Horizons Planet Pack) Quote Link to comment Share on other sites More sharing options...
Triop Posted June 21, 2016 Share Posted June 21, 2016 (edited) No idea . . . But she looks terrified................. Edited June 21, 2016 by Triop Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted June 21, 2016 Share Posted June 21, 2016 39 minutes ago, Triop said: No idea . . . But she looks terrified................. Probably goes nowhere very fast. Quote Link to comment Share on other sites More sharing options...
Triop Posted June 21, 2016 Share Posted June 21, 2016 (edited) 3 minutes ago, CatastrophicFailure said: Probably goes nowhere very fast. Indeed, she did not make it.... † Marcie Kerbal ???? - 21-06-2016 Edited June 21, 2016 by Triop Quote Link to comment Share on other sites More sharing options...
Rocketology Posted June 21, 2016 Share Posted June 21, 2016 On 6/17/2016 at 6:51 AM, cubinator said: How did you get the Mun looking all rocky like that? It looks really cool! Yes, it's KSPRC mod. Quote Link to comment Share on other sites More sharing options...
Archgeek Posted June 21, 2016 Share Posted June 21, 2016 'Manually ran the numbers on the Xenon Tempest Mk 3 protoype: Spoiler for maths that belong in a spreadsheet: Spoiler Two puffs are present to allow mono to be used for boost thrust at a better efficiency than just holding 'H' 560 mono for 2.24t, set aside 60 for rotation/docking, 500 for 2t Puff Isp: 250s, thrust: 40 total min puff dv: ln(106.736/104.736)*250g = 46.39m/s @.038-.039 TWR max puff dv: ln(12.725/10.725)*250g = 419.4m/s @.320-.380 TWR Main drive: 12 ion engines in a puller configuration for 24kn of thrust S8: ln(106.736/88.016)*4200g = 7945m/s TWR: .0229-.0278 S7: ln(72.686/60.206)*4200g = 7761.5m/s TWR: .03365-.0406 S6: ln(49.886/40.526)*4200g = 8562m/s TWR: .0490-.0604 S5: ln(32.411/26.171)*4200g = 8811m/s TWR: .0755-.0935 S4: ln(20.861/16.701)*4200g = 9164m/s TWR: .1173-.1465 S3: ln(12.725/12.125)*4200g = 1900m/s TWR: .1923-.2018 total minimum main drive dv: 44.14km/s (burning all 2t of mono gives each stage roughly 1km/s more, for a max of around 50km/s) 44.14km/s minimum vacuum dv from the main drive system alone, using an un-optimized staging scheme -- this thing makes my previous designs look quaint. Quote Link to comment Share on other sites More sharing options...
Vermil Posted June 21, 2016 Share Posted June 21, 2016 (edited) 6 hours ago, Dispatcher said: Your problem is: not enough boosters! Seriously, good luck in your future attempts. That looks like it was a lot of work. Of course I need moar boosters! I just couldn't find any place to put them. ...I had already put some extra rockets there. Edited June 21, 2016 by Vermil Quote Link to comment Share on other sites More sharing options...
Vermil Posted June 21, 2016 Share Posted June 21, 2016 (edited) Well, the Magma_A MkII superlifter (which was perfectly fine before v1.1) continued to progressively break into pieces in the lower atmosphere during launch attempts. But the Orpheus_X7 payload did survive sometimes to allow me to make test-landings. This one wasn't ultimately useful, as it ended up in the water. But it did confirm that the rocket driven ejection of the stabilizer boom after all chutes are deployed now works as intended. Well try again. This time I came down on a nice piece of land. There was mainly only one immediate problem. Descent rate was very high. I think I originally - when I once deviced this thing - counted on Eve's thicker atmosphere to make the chutes more effective. But I don't think the more realistic aerodynamic model works that way any longer? I'll throw on another 16 XL parachutes. Anyway, the high sink rate forced me to burn way too much fuel for the landing. I landed alright though and on Kermin's gravity the landing strut arraignment work. But it wouldn't be able to reach orbit on Eve with that fuel loss on landing. Question is if it'll be able to do so even with full fuel load? I've started to doubt that. Another concern is the nose heat during ascent, which I gather is a problem on Eve. On Kermin, Orpheus has no problem reaching orbit, even throttled down, with plenty reserves. So I went through the motions. Also re-entry and landing. And discovered that I'm not happy with the crew module. I must have designed this a long time ago. Edited June 21, 2016 by Vermil Quote Link to comment Share on other sites More sharing options...
DunaRocketeer Posted June 21, 2016 Share Posted June 21, 2016 I've gone as far as I can with my in-line winged boosters, so I've created two near-identical winged boosters strapped to each other.. They look rather like skylons. One is all propellant and remains suborbital, the other is half prop, half cargo. They're crossfed, but I jettison the crossfeed pipes around 10km to keep the whole thing balanced towards the end of the burn. It'll lift 36 tons comfortably, but I'd like it to lift 40 comfortably before I transfer it to my main game. Quote Link to comment Share on other sites More sharing options...
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