OhioBob

Another goodie it that rockets work by pushing against the air. Some in the conspiracy arena have used this one to deny the existence of spaceflight altogether (rockets obviously don't work in a vacuum). I wonder how they think their cell phones, GPS, and satellite TV work.

The FAR method, as you describe it, isn't correct either. Atmospheric pressure in KSP is computed using a constant scale height, which implies constant temperature. If temperature is going to be varied, then the pressure-height profile should be reformulated. Using the same pressure-height profile as the stock game (i.e. constant scale height) while varying the temperature necessitates the improbably scenario of variable molecular weight. In real life this is not the case. The lower layers of known planetary atmospheres are well-mixed and homogeneous with constant molecular weight (though this begins to change at extreme altitudes). The stock model is a reasonable simplification that works well for a game. If FAR wants more realism, then it should completely remodel the atmosphere rather than trying to retain some aspects of stock while changing others. All that's needed to formulate a model is the temperature-height profile (typically defined as a series of linear functions of height), the pressure at sea level, and the gas molecular weight (or, alternately, the density at sea level). Rather than using the stock formula to calculate pressure, atmospheric pressure should be computed using different formulas for each segment of the temperature-height profile. If the FAR method, as I understand it from NathanKell's post, was intended to produce greater realism, then I believe it failed. It simply traded one unrealistic assumption (constant temperature) for a different unrealistic assumption (variable molecular weight).

I've spent a large amount of time debating with conspiracy theorists who deny the reality of the Apollo moon landings. The stupidity of those people is boundless. They've said so many ridiculous things that it is impossible for me to pick out just one.

Learn the new aero model. Many of my rocket, spacecraft, and mission designs are based on aerodynamic simulations that I perform outside of the game. I'll have to learn how the new aero model works, modify my simulations, and develop new design guidelines.

Two - 1 in sandbox for testing, and 1 in career for my actual gameplay.

I've been playing the game for only eight months, so I haven't had time to evolve all that much. I started in sandbox just long enough to learn the game basics, then I switched to career mode. I played one game in career mode using 0.24-0.25, then I started a new career game when 0.90 was released. At first I refused to use any mods because I wanted to become familiar with the stock game. Eventually I started adding mods that help make gameplay a bit easier (Kerbal Engineer Redux, Precise Node, and Kerbal Alarm Clock), but I've stayed away from mods that change the game's physics. I'm waiting to see what Squad does with the aerodynamics before I consider using something like NEAR or FAR. So far I've limited myself to using expendable rockets. I haven't tried anything with spaceplanes or SSTO. My current goal is to complete a landing/return from every planet/moon in the solar system. Right now I'm working on the moons of Jool, which I should have completed soon. That will leave me with just a return from Eve to finish the goal. I don't know what I'll do after that; I my take a break until version 1.0 is released. At that time I'll probably start with a fresh game, though I'll likely try science mode rather than career mode (I don't think I want to go through the tedium of completing a bunch of contracts again to build up a nice cash reserve). I'm really curious to see how version 1.0 plays. The first thing I'll have to do is relearn the game based on the new aero model. Most of my rocket designs are based on simulations that I performed outside of the game. I'll, of course, have to redo that work to develop new design guidelines. I've also developed aerobraking and atmospheric entry simulations that allow me to determine the correct periapsis for targeting a specific orbit or landing site. That will have to be redone as well. Once I've got a handle on the changes, I'll have to start flying some new missions. I have no idea what those will be yet.

I build for efficiency - I don't really care what it looks like. I design space missions first - the spacecraft is just the tool used to complete it. I design my craft to complete the mission using as little mass as possible, nothing more. As an engineer, I find that something designed for optimum efficiency has a certain beauty to it, even if others think it is butt ugly. edited to add... Although efficiency is extremely important in my designs, it is not my primary goal. My #1 goal is always mission success. I will, therefore, make compromises to efficiency is if it will enhance the likelihood of mission success.

That is the contracts completed. After you start completing contracts it will tell you the number completed, something like (((15))). Clicking on the icon gives a list of completed contracts.

I've used the Mk55 frequently on two-part spacecraft that are connected inline with a docking port. The Mk55 provides a good engine for the forward part. Example: Maximus97 is right about the upgrading of the Mk55 in 0.90. I believe it's vacuum specific impulse was changed from 290 s to 360 s. The Mk55 is still on the heavy side, but it's performance is now good enough not to be a detriment.

I did too, though I think I have a good excuse. I've been experiencing some sort of glitch that has been messing up my orbits. I'll inject a spacecraft into an interplanetary trajectory and set up a nice encounter with the target planet. I'll then leave the spacecraft in cruise phase while I go a do something else. I'll then come back to it and the orbit has changed. My encounter is gone and I'm in a significantly different orbit than I left. There is no explanation because I didn't perform any burns and there are no other bodies nearby that could have altered the orbit. This has happened to me at least three times since the 0.90 upgrade. It has to be some sort of bug. Since I believe I got screwed over by the game through no fault of my own, I figured I was warranted in using infinite fuel to get me back on course (in one case I needed a 850 m/s burn to reproduce an encounter with my target planet). Has anybody else had this problem?

The SRM nozzles are also canted outward 3o, which reduces the length of the moment arm. Performing a quick back of the envelope calculation, I estimate that the RD-180 would have to be gimbaled at and angle of about 2o-2.5o to compensate for the off-axis thrust of one SRM.

It my understanding that they gimbal the RD-180 main engine to compensate for the asymmetry. - - - Updated - - - It's my understanding that the vehicle has fixed attachment points for the SRMs to provide some ease and consistency in vehicle assembly and servicing. To maintain symmetry while attaching varying numbers of SRMs would require additional or moveable attachment points. (edited to add the following) To illustrate this point, if 0o is always the attachment point of the first SRM, then the following points would be needed to provide symmetry for 1 to 5 SRMs: 1 SRM - 0o 2 SRM - 0o, 180o 3 SRM - 0o, 120o, 240o 4 SRM - 0o, 90o, 180o, 270o 5 SRM - 0o, 72o, 144o, 216o, 288o That's a total of ten attachment points. Plus you would need a service gantry that provides access to all those points. Instead they provide five permanent attachment points and always attach the SRMs in some arrangement to those five points. The arrangement of the points, 2 on one side and 3 on the other, also makes for easier gantry access.

You can always do something like below. It doesn't have much grip on a steep slope, but for landing on the flats of Minmus it should work just fine. - - - Updated - - - Those are conveniences but I don't think you NEED any of them. I've never used MechJeb and I've done plenty of interplanetary stuff. I've just recently started using Kerbal Alarm Clock. It's a very nice feature but it's certainly not needed. The mod I've used the longest, and the one I find most useful, is Kerbal Engineer Redux (KER). The best thing about it is that it computes the ∆v of your rockets and spacecraft. Computing ∆v is doable by hand (and it's a good idea to learn how to do it), but after a while it's convenient to have KER do it for you. KER also gives orbital information, which is nice, but it's definitely possible to get to other planets without it. One of the other things about KER that I really like is that it tells what biome you're currently flying over. That's really nice when biome matters in the science you're trying to collect, such as EVA reports.

Yeah, you're right. I should have realized that. Points are award on the order in which the science is returned to Kerbin, not the order that it is collected. This actually makes real-life sense because the knowledge is gained when the data is analyzed by scientists back on the home world. - - - Updated - - - You can also wait until you've researched the Advanced Grabbing Unit. That would make it easy to grab hold of the stranded pod and bring it back to Kerbin intact.

I haven't developed a favorite yet.

With Mystery Goo and Science Jr. you collect science as follows: In Space, High/Low - Global Flying, High/Low - Global Surface, Landed/Splashed - by Biome Kerbin has 9 different planetary biomes, plus the launch pad, runway, and KSC grounds. That gives you 28 experiments you can run without leaving Kerbin. You also have crew reports, EVA reports, and samples. The easiest thing is to just send a pod with Mystery Goo and Science Jr. to the launch pad, run the experiments, do a crew report, get out and do an EVA report and take a sample, and then recover the vessel and crew. You can even do an EVA report while hanging on the ladder and you'll get science points for an EVA "while flying low over launchpad". Do the same thing at the runway. You've now collected some science without costing you a thing. You can now repeat this by doing quick hops to other biomes. Launch up and to the side a short distance and you'll land at KSC, or at Kerbin shores. Do a short hop to the east and you'll splash down in the water and can collect science from there. Do a short hop to the west and you will land in Kerbin grasslands. Eventually you can start expanding out to more distance biomes (be wary of mountains though because you can tumble down a steep slope if you're not careful). - - - Updated - - - Yes, there is a diminishing margin of return with science. Some science gives you full value the first time (such as crew and EVA reports), thus repeating it gains you no additional science (though it can satisfy the conditions for a "collect science from X" contract.) Other experiments (such as Mystery Goo and Science Jr.) give diminishing science points with each repetition. The reduction is significant, so it is rarely worth doing it more than twice (unless it doesn't cost you anything). That's a problem because you'll never get that same science value again by repeating the mission. You should be able to rescue him but it will take patience. If you can't bring his pod back you can always have him transfer to an empty pod via EVA, but that's going to take some practice. You will also need to make such that Jeb takes the science data from the old pod and transfers it to the new pod, or else you'll bring Jeb back but not the science points.

I always forget that stage lock is an option. I don't stage accidentally often, but it has happened to me on a few occasions. That's when I use F5/F9.

I second that.

I just recruited Billy Bobble Kerman.

In KSP the atmospheric and vacuum values of Isp are somewhat arbitrary. It might be helpful to understand why, in real life, this difference exists. To understand we must look at the basic thrust equation: F = q * Ve + (Pe - Pa) * Ae where q is the rate of the ejected mass flow, Ve is the exhaust gas ejection speed, Pe is the pressure of the exhaust gases at the nozzle exit, Pa is the pressure of the ambient atmosphere, and Ae is the area of the nozzle exit. Thrust has two components, the first, q*Ve, is called the momentum thrust, and the second, (Pe-Pa)*Ae, is called the pressure thrust. Most of a rocket's thrust comes from momentum. Pressure thrust is the result of unbalanced pressure forces at the nozzle exit. For a given rocket engine operating under steady state conditions, the values of q, Ve, Pe, and Ae are constant. The only variable on the right hand side of the equation is the atmospheric pressure Pa, which varies from sea level pressure to zero in a vacuum. Thrust is maximum in a vacuum, when Pa is equal to zero. Thrust is minimum at sea level, when the maximum thrust is reduced by the amount Pa*Ae. Specific impulse is given by the equation, Isp = F / (q * go) where go is standard gravity, 9.80665 m/s2 in real life and 9.82 m/s2 in KSP. Putting it all together, and letting Pa equal sea level pressure, we can see that Isp (vacuum) - Isp (sea level) = (Pa * Ae) / (q * go) As I've described above, in real life q is typically constant and it is F that changes as a rocket ascends through the atmosphere. As others have explained, in stock KSP it's the other way around, with F constant and q variable. From what we've been told, this is about to change with the release of version 1.0.

Yes, there may be an issue with non-stock science experiments. I once tried to transmit science from a SAR Altimeter (ScanSat mod) to complete a contract and it didn't work. It didn't give me an error message but I didn't get the money for completing the contract. I tried again using a Gravioli Detector and it worked. I've never had a problem using any of the stock science instruments.

a). gravity turn with A/D a). kill horizontal speed, then vertical (however I do set my periapsis low over the landing site so I have a fairly short fall) . use I, J, K, L, H, N

I think it is a good idea to always include a repeatable science experiment on any probe or lander that will be left in place. It is very common to get "collect science data from space around X" from places you've already been. You may even get the same contract multiple times. If you already have an old probe/lander parked there, you can fulfill the new contract immediately and for free. Thermometers are good for this because they are cheap, repeatable, and can be used both on the surface and in space (low). Example: I got an old robotic lander sitting on Moho whose primary mission has already ended. Since then I have twice received "collect science data from space around Moho" contracts. All a had to do was return to my lander, pulse the engine to lift a few meters off the ground, quickly log the temperature before touching back down again, and transmit the science data. Contract completed in almost no time and easy money in the bank.

I actually think 1.75 m makes a little more sense. With 1.75 m we have, 1.25 > 1.75 m = +40% 1.75 > 2.5 = +43% 2.5 > 3.75 = +50% and with 1.875 m we have, 1.25 > 1.875 m = +50% 1.875 > 2.5 = +33% 2.5 > 3.75 = +50% And if we do it by cross-sectional area, with 1.75 m we have, 1.252 > 1.752 m = +96% 1.752 > 2.52 = +104% 2.52 > 3.752 = +125% and with 1.875 m we have, 1.252 > 1.8752 m = +125% 1.8752 > 2.52 = +78% 2.52 > 3.752 = +125%.

Furthermore, to complete a contract the science doesn't need to be new. In other words, if you get a contract in the future that asks for science from a place from which you've already collected science, you can repeat the same experiment. Even though you may not collect any new science points from the repeated experiment, it will fulfill the contract. (edit to add) ... There may be an issue of this not working with some mod science instruments. It should work with stock science instruments.