Reusables

Thanks! What about drag&lift? Anyone know whether it is dependent on drag or lift?

The problem is that the temperature is not constant although it's hardcoded. It makes the two different. For example, kerbin's ground level temperature is over 280K. The temperature of the low stratosphere is under 210K afaik, which is only three fourths of that of ground level. This means that the pressure decreases 4/3 times faster than the density does while gaining altitude in troposphere. So, I think this does matter.

Yeah, I know that. Though I want to know that whether they affected by pressure profile or density profile. (afaik density = Nm/V = nm where n is number density, but those details are trivial in this case)

While exploring the ksp atmosphere, found out that it's important to know drag/lift/thrust profile for each height. So what really affects those profiles, pressure or density?

Found out that high speed performance is more important than stationary TWR itself. So my analysis was wrong for planes It needs higher rotor speed to perform well on high speed, which requires higher angular speed. Since there is strict limit of 50rad/s in ksp physics engine, the performance is quite limited. Also friction tends to be bigger with higher angular speed, especially when the angular speed approaches the physics limit of 50rad/s. So.... decided to go wider. (bigger diameter) Anyway, in process of trying to make an Eve SSTO, made propellers with TWR 1.88 for low speed(120m/s) on 3950m. (Drag of the engine is excluded; It TWR down to 1.5~1.6, propellers weigh 13t, 6.5t for each)

Doesn't it cost sqrt(2-sqrt(2))X for the direct plane change, and nearly (2sqrt(2)-2)X for SOI boundary plane change? Which are 0.765X and 0.828X each. If you meant energy cost, the energy cost per delta v is dependent on speed, thus kinda redundant.

Put control surfaces as far from center of mass as you can, as it gives bigger torque for the control. Also, it's okay to put center of lift just behind and higher of the center of mass. As long as center of drag is behind the center of mass, its head will fall on stalling. Just make the tail more draggier.

Congrats! You got the barrier of 3G! Though, the scoring is based on payload mass, which is (final mass) - (fuel tank dry mass) - (engine mass) in common. Would you provide those information? Or, would it be better for me to change the scoring to include only fuels and decouple-able 'payloads'(satellites and such) ? Since it's much easier.

Reach orbit in high gravity environment! Basically, this challange is just about getting orbit efficiently on Kerbin. However, with gravity multiplier cheat, it won't be easy! In these harsh environment, haul fuel/payload to orbit as much as you can! Rules: 1. No cheats allowed, aside from the gravity multiplier cheat. - Entrants should keep the gravity cheat on throughout the entry, with the multiplier given by each level. 2. No kraken drives, no clipping of functional parts. 3. The orbiter can either be manned or unmanned, refuel it in any way if you can. (Docking is allowed as well) 4. Reach stable orbit out of the atmosphere, using any ways fitting in the rules. 5. Mods allowed: - Part mods with reasonable chemical tanks/engines only. (No OP tanks/engines or other propulsion concepts) - Visual mods like Scatter, SVE and such. - Piloting mods like Mechjeb, kOS and such. - Editor mods like Part Angle Display, Editor Extension Redux and such. (Finished product should be stock craft with it) Any other mods aside from these are not allowed. Entry Submission Rules: 1. An entry should contain screenshots or videos to prove the completion. Imgur or Mission Reports is recommenfed. 2. At least one of the screenshot should contain debug screen indicating that only gravity cheat with appropriate multiplier is on. More than once is recommended. For video submissions, show it once and capture continuous process to orbit in the video. 3. Screenshots should include craft in VAB(for total mass), on LaunchPad, liftoff, subsonic flight, gravity turn, supersonic flight, high atmosphere flight, reaching apoapsis, finishing orbit and craft on orbit and more if you want. Scoring Scheme: 1. Score is given by (Payload mass) / (Total mass) - 'Payload' means parts got to orbit which is neither fuel tank nor engine, and fuels left on the orbit. Crew cabins count as payload, but not any other multipurpose fuel tanks like wet wings. - 'Total' means every parts launched for this mission. This includes pre-launched refueling ships in orbit. Levels: I. Moderate gravity (1.7g): Reach orbit on Kerbin with gravity multiplier of 1.7. (Range of 1.68g~1.7g is allowed, due to the sensitivity of the scroll bar) I1. Spaceplanes (too) Powerful Reach orbit, using jet engines. Every bits you launched should reach stable orbit. I2. Heavy Rocketry Reach orbit without jet engines. Isp. Heavily Usable Rocketry Reach orbit without jet engines, with every bits you launched reaching stable orbit! (Yes, this one is specially aimed for conquering a *punishing* body) II. High gravity (3g): Reach orbit on Kerbin, with gravity of 3g! 2.88g~3.0g is allowed. III. Super gravity (5g): Reach orbit on Kerbin with gravity of 5g! 4.98~5g is allowed. V. Hyper gravity (10g): Use any possible way, to reach orbit with Hyper gravity of 10g! (Only 10g is allowed, since it's at the end of the scroll bar) (This should be impossible, though let's see if I'm wrong) Results: I. Moderate gravity (1.7g) I1. Spaceplanes Powerful I2. Heavy Rocketry Isp. Heavily Usable Rocketry II. High Gravity (3g) 1. MarvinKitFox - Asparagus-staged Mammoth Rockets to 11k X 14k orbit. (Score pending) III. Super Gravity (5g) V. Hyper Gravity (10g) + My entry will be up soon! (Though I doubt I need one)

Yeah, but spaceplane needs lift. I thought it would be enough for LF storage, and just realized now that the Big-S Wing Strake is much lighter than that. Also didn't realize that Mk0 is much better for the mass; Thanks for let me know that.

Today, I found out that Big-S wing strake has 0.5t of liquid fuel storage. Since its dry mass is only 0.1t, the dry-wet ratio will be 6 which seems too powerful. In comparison, Big-S Delta Wing has dry-wet ratio of 4, and normal fuel tank has that of 8. Am I wrong somewhere here? Wouldn't this make them too OP, making liquid fuselages redundant for spaceplanes? Also Big-S Delta Wing is only useful for aesthetics and reducing parts count, isn't it? Or are there some weak points of it?

This is what made me think that spark has little to no thrust; Found out that I got an occlusion there. Although it was nearly on the edge, it gave no thrust at all.

I think it's like 'infinite energy' or 'infinite electricity' and such. Both are pursued much more than it's really needed in either game or real life.

I think so, too. The pressure epn't match at first. Though it'll be interesting enough, I think. Maybe oxygen could exist from the H2O vapor consisting most of the planet atmosphere? EDIT: Just realized that water really likes to absorb carbon dioxide, effectively cooling the planet. So no, nothing interesting left, just IRL Laythe impossible.

Thanks, again! Got this: http://m.wolframalpha.com/input/?i=2*G*(1.43*10^27kg)*(5300km)%2F(288100km)^3&x=0&y=0. So I was wrong, tidal force is still small here. It's neglectable even on 2 times of its own radius. (Reference: https://en.m.wikipedia.org/wiki/Tidal_force) Then... what will happen if we send the Venus to the IRL Jool orbit? The tidal force will still be able to give enough heat to be geologically active. Probably, high pressure planet with water? (Though no oxygen in this case) (Or jupiter orbit as well. This can happen as solar system is not perfectly stable)

Thanks! Sorry, but can I ask for real scaled value of Jool's mass and Laythe's radius, too? Is it right to scale the mass 100 times and the radius 10 times?

Well, the first constant should be 0.25 as it receives solar flux in the disk and emits on the whole surface (the sphere). Then it correctly gives 252K for Earth. With its greenhouse effect, it goes up to 288K IRL. (Although the Venus rotates slowly, the atmosphere equates the temperature of dayside and nightside. 0.5 is given for dayside of atmosphere-less slow-rotating planet) Besides, the Venus will retain temperature of 231K on the jupiter orbit. http://www.wolframalpha.com/input/?i=737K*sqrt(Semi+Major+axis+of+Venus+%2F+Semi+Major+Axis+of+Jupiter) Considering the relatively high albedo of the Venus, this can be bigger.

It's improbable for cold planets like the Earth, though. Cold trap keeps the water vapor from getting higher by condensation and precipitation - clouds. Nevertheless, I think it's obvious that Laythe can't retain its atmosphere due to the tidal force. It's simply too close to the Jool. What will the orbital parameters be if Laythe is scaled up for IRL?

For me, it's a spaceport supporting refueling, (orbital) assembly, and recovery/rescue. Also it's waiting room for the next spaceflight. Also, it can act as center of the Commnet.

I think the tidal force ripping off the atmosphere is the bigger problem. IRL Laythe could have higher temperature from massive greenhouse effect, but tidal force would prevent it from retaining its atmosphere. Besides, what happens if all of those materials is already oxidized? If it is ejecting water through heavy volcanism and water vapor partly dominating the atmosphere goes up to high atmosphere where it'it's decomposed. Maybe it can par with the ejected mantle substances, oxidizing it immediately. (It can't just retain its atmosphere as stated above, but just a guess)

Oops. What I meant was free oxygen gas. Calculate the greenhouse effect of Venus, it should be bigger than 30. So the temperature could be still near the freezing point of water even if it is placed on 5AU. So, it's not that far. It's just not something earthy atmosphere can give. Well, Ganymede retains some of its own magnetic field which is just a bit under the surface on the high latitude. Since the Earth is much bigger, magnetic field will be big enough to pull the boundary out of its surface/atmosphere. Also, oxygen is not dependent on the presence of life, try searching exoplanets with oxygen. water vapor broken by either UV ray or cosmic rays produces oxygen gas on high atmosphere. A common planet in process of runaway greenhouse effect can experience it, as I said earlier. EDIT: Look at the atmosphere part of Ganymede, it has tenuous oxygen molecule atmosphere caused by some radiation.

Actually there is a mechanism which produces oxygen on the atmosphere: UV rays breaking water vapors into hydrogen & oxygen gas. This is quite common for planets getting runaway greenhouse effect, since they have relatively high water vapor concentration in its high atmosphere. The hot temperature causes water vapor to go up higher, where it's prone to bombardment of solar UV rays. The resulted hydrogen gas escapes the planet, while the oxygen gas falls to the bottom of the atmosphere due to its high molar mass. On the other hand, cold planets like our Earth remains intact thanks to the cold trap. It prevents water vapor to go up and disintegrated by UV rays. Also this is what our planet, Earth, will experience in the future. Since the luminosity of the Sun is increasing throughout its life on main sequence, Earth will get hotter and hotter. Once sufficient temperature is achieved, it will cause the positive feedback of the runaway greenhouse effect. Then this planet will be harsh deserted world, where neither water nor any traces of life exist.

Proper Laythe aerocapture through the high atmosphere provides both powerful gravity assist and enough aerobraking. Laythe is quite a bit closer to jool than Tylo, which makes deceleration more effective. Moreover, thanks to its faster speed gravity assist could give more deceleration on Laythe than that on Tylo. So, I think Laythe powered aerocapture will be efficient enough capture for short-term missions on Jool.

I think it's possible if it had thick atmosphere. Venus, which has 737K of temperature IRL, should be cold as 300K if it were blackbody. This means that it's emitting 36.4 times less heat for its temperature. (As a reference, earth has 288K mean temp. while it would have 255K mean temp. if it were blackbody, emitting 1.63 times less heat for its temp.) Considering that laythe gets 25th of the sunlight that Kerbin gets, the temperature of Laythe could be gained with atmosphere slightly thicker than Venus. (Or probably, methane-rich atmosphere with water vapors dominating it) It is questionable whether it could gain and maintain the atmosphere, though. Unlike Venus, it's too cold for runaway greenhouse effect. The tidal force makes it unlikely to maintain the atmosphere as well.

Trying to make Eve SSTO with propeller plane even though it's nearly impossible. Today, I found that aligning CoT is important as well with CoL and CoM, while testing the plane with gravity cheat of 1.68g. http://imgur.com/a/VCCuZ