Reading/Resources to understand more about engineering and rockets effeciency

[SalehRam]

So, first I'm an engineer... but not a rocket engineer. I'm a networks engineer, so I am having some issues with rockets and getting the most effectiveness from them...

I hate to use mods, I will not use mods other than KER, Alarm Clock, and Docking Port Alignment Indicator...

Are there any good places that speak a very simple language to teach people who are trying survive challenges of the game without getting lost in the circle of try and error, wrong designs and mostly TIME...

I know there will still be trial and error, but with the way it goes for me now, I'm sure I won't be able to do much more than Duna trips...

I went to Eve with a probe, but as it is known, there was no return back... so that is a challenge, and I want to pass it without reading others experiments and see their designs... as I want to do it all on my own.

But I feel I am missing something fundamental I don't know what it is...

So I would like to do more reading about space travel and rockets design for interplanetary, in addition to flight planning from launch to re-entry... As I consider this "game" more than a game really...

Thanks

Edited February 25, 2015 by SalehRam

[brdavis]

I'm not sure… if you are using things like KER than you understand things like delta-V, thrust-to-mass ratios, etc., correct? I can recommend some good books on aerospace, but they're going to cover things a lot more in depth than KSP simulates…

If you feel like you are "missing something fundamental", well… where and when do you start to feel like that? Getting to Duna means you've done a good bit. Getting back from Duna requires planning. And once you've done that thinking and planning, you can start thinking of scaling up to Jool or Dres or something (or in towards Eve and Moho… although catching MoHo is *still* something I've not personally managed…)

If you want to "do it yourself", try it in a scientific fashion: trial and rror aren't bad *if* you analyze what worked and what didn't (and why) afterward.

A little confused on how to help you, while letting you "do it all on your own"… :|

[Streetwind]

Honestly? When I started KSP, I went on wikipedia (English, due to having the most articles), looked up delta-v, and started following whatever cross-references seemed relevant from there. I probably read 30-40 entire pages on rocketry and physics.

Wikipedia doesn't go into the depth that a real textbook does, but it does give a useful overview.

[Rokmonkey]

So, using KER is going to help you a lot, good call on that one.

Resources to learn from:

For basic rocketry in a simple language, check out the KSP wiki, there are some good guides there on orbital mechanics as well.

As far as rocket building goes, I will research and study rockets that have been used in reality, so Wikipedia is an excellent resource, especially with their "Launcher Families" lists. If you find one you like, learn about it on it's page, it's staging launch profile etc. Personally, I mimic realistic designs, so I use Ferram Aerospace, which eliminates the stock aerodynamics and replaces it with real aerodynamics. I'm a mechanical engineer, so that sort of thing causes me to cringe, especially when I see pancake rockets working.

I highly recommend you watch Scott Manley's videos. He has excellent tutorials that teach you basic mechanics. As well, if you watch either his Reusable Space Program or Interstellar quest, he frequently discusses actually rockets, orbital manuevers and all things space programs. It is highly educational. He uses mods, but the general practices and theory is the same regardless.

[Moonfrog]

Have you tried looking at a delta V map of the kerbal star system? Should provide rough estimats of how much Delta V u need for a return trip, give you the information you need to build your rocket more efficiently. Do you just want information on building rockets efficiciency, like general rules and stuff? Do you want information on the parts available to you, or tips on career mode to help with funds and science gathering. Or tips on how to complete particular contracts?

[EtherDragon]

If you want to get down to the mathematical nitty gritty, Kerbal Space Program really comes down to five not overly complex equations and some derivations from them. I don't know them all off the top of my head, but they are easy to find.

These first three are relevant because Newton discovered they not only pertain to planets and moons, but all objects orbiting a central mass:

1. Kepler's First Law of Planetary Motion - All planets move in an Elipse with the Sun at one of the Foci. One critical equation that comes out of this is the formula for the Semi-Major Axis: Sma=(Pe+Ap)/2

2. Kepler's Second Law - Orbiting planets sweep out equal areas in equal time. A couple equations can be derived from this law that tell you exactly how much you need to change your velocity to change one elipse into another.

3. Kepler's Third Law - The Square of the Period is proportional to the cube of the semi-major axis: R=P^2/Sma^3, where R is a constant. This one can be easily derived into a simple equation to determine optimal transfer angles for interplanetary travel.

4. Thrust to Weight Ratio (TWR): Which is simply Rtw=T/W

and

5. Tsiolkovsky's Rocket Equation (this one I have MEMORIZED) which describes how much total change in velocity (referred to as Delta-V) a rocket has based on it's mass, fuel, and engine efficiency: Dv=Isp*G*Ln(M0/M1), where M0 is initial (full) mass, and M1 is final (empty) mass. Oh and G refers to the force of gravity at sea-level, which is ~9.8m/s^2.

I'm like you, I would rather run a quick equation through a calculator and come up with the answer than run an add-on. Especially when it's really not that hard. It is Rocket Science, but it's not difficult.

[Pecan]

For rocket science itself, in an easy form, why not try NASA's Beginner's Guide To Rockets.

For a more wide-ranging, borders-of-possibility, look at space; Preliminary Notes on Atomic Rockets

[SalehRam]

Well,

I know about TWR, and delta-v, and I try to maintain a minimum TWR of 2 on all stages if I want to go to Duna on a round trip... same as Mun... (Though Mun trips became like a walk in the park for me lately...)...

The thing is when it comes to interplanetary, as it takes more dV, and thus more fuel, leading to a larger rocket design... it is there where I start to fail and sometimes getting frustrated... I did manage to get an efficient design for Duna (after ages of trial and error attempts, while I think it could be easier somehow), but when I tried to do something for Eve, I ended up getting enough fuel for 1 way trip, so my probe got stuck on it without fuel to even try and experience the ascend from there and how it is hard...

Maybe I am exaggerating a bit, but it could be all I need is trial and error, but for all the resources up, I'll make sure that I take a look on them and read them carefully... as Physics is something interesting to me anyways and I am looking forward to the incoming fixes to the aerodynamic system...

Appreciate your input guys and I feel happy to be part of such community

[NathanKell]

The problem with reading real information on things is that KSP is decidedly not real. There are many mods available that make it behave more in line with real physical laws, but reading about real rocketry you will learn things that either do not apply (reentry corridors and the danger of reentry generally, boiloff, liquid hydrogen's low density, problems reigniting engines or throttling them), apply much more weakly to KSP due to how small things are (staging), or are wrong for how KSP simulates things (aerodynamics and what a gravity turn actually is, Thrust and Isp, etc).

If you want to be able to apply real life knowledge to KSP, you at least need FAR.

Just as a side note, you don't need a TWR of 2 at all once you're in orbit; you can make do with as little as 0.2 or so. Even getting into orbit you don't need such a high TWR; at least with FAR you'll do better with a first stage of starting TWR of 1.2 to 1.5, and an upper stage starting TWR of no more than 1.2.

[Freshmeat]

If you want to build the right rockets for the right situation, the most important thing is understanding the delta V map. It tells you the expected minimum cost for going to a planet. Build your rocket so the return is accounted for, taking not that you can do aerobraking from a very high orbit. Start with the top stage and build downwards, but the tricky thing is that you need exponentially more fuel for a linear increase in payload. As of writing, Fly on budget is down, but I hope it gets back up. The author shows with how little you can get by, serving as an inspiration. You might want to review your TWR requirements, I think 2 is a tad on the high end, for takeoff from Kerbin a TWR 1.7 or so make for a speed around the terminal velocity, as presented in this table. I think you already know that TWR changes with the relevant body, and you can adjust in KER.

The second part is getting there. I have only little actual experience in interplanetary travel i KSP, but the launch window planner tells you when to launch and what way to point your rocket when you make the escape burn. It saw me to Moho on a one way trip, and it had a decent estimate of the actual fuel consumption. Similar information, with some handy diagrams, are presented at Interactive illustrated interplanetary guide and calculator for KSP.

If you want to go into orbital mechanics, the science that lies beneath the above pages, you can get a decent introduction here. Personally, I found it better than my university textbook (Kleppner & Kolenkow), and being an engineer, it should not be hard to follow.

Hope this helps, and remember to seach the forum and ask around. People are awfully friendly around here

-Freshmeat

[Pecan]

...but when I tried to do something for Eve...

Eve is HARD! The gravity is so high and the atmosphere so thick that launching from Eve is i) really demanding (~12km/s dV from sea-level), ii) impossible with a reusable (SSTO) vehicle, iii) takes a BIG, efficient, vehicle that itself hard to launch from Kerbin and get to Eve in the first place.

[SalehRam]

Gonna bookmark this! I really appreciate your input guys!

And, @Pecan: I know that Eve is hard, the thing is, I never managed to do a normal trip to it without many troubles on the design side, that's why I mentioned it, being a near planet along with Duna... so I'm not saying I want to do it the same way I go to Duna, it is just I'm looking for a point where I know that I am doing it right and my next problem is something I have no control on!

And judging from your input guys, I think I am on the right track, I just need to check some resources including the dV map, and read the links you put up.

Edited February 25, 2015 by SalehRam

[Pthigrivi]

Yeah don't get down on yourself. Eve isn't just hard, there-and-back missions to Eve are generally considered some of if not the most challenging missions in the game. It takes a lot of clever staging, a huge amount of delta-v, usually aerospikes and either precision landing on top of a mountain or driving up one with a huge, wheeled lander, or building and landing a very clever space plane. It's one of those things even veteran players take a great deal of time and planning to pull off. Only Tylo missions come close. Even though they're farther away Dres and Jool are much easier to deal with. Try a Laythe mission! Air breathing engines work there making for some really cool design options. You'll also find LV-N's very useful for your transfer stages when going interplanetary. You can use those worlds to get used to what engines are good for what and then try to tackle Eve with a bit more experience in KSP's quirks.

Edited February 25, 2015 by Pthigrivi

[Moonfrog]

When you do interplanetary voyages are you performing a direct planet transfer or are you going into kerbals orbit and then into the duna / eves orbit? most efficient way is to do a direct transfer using a window planner. Also usually more efficient to use a seperate mothership and smaller lander for interplanetary trips, like the appollo mission to the moon.