Doc

Yeah, I gotta agree with you there. Not nearly enough people are interested in playing on 'uberhard' mode - which is what some other people are asking for. By my accounting, KSP is a reasonable 1st order approximation of a space simulator. Yes, there are a ton of simplifications that have been made but here is the deal with building a simulation or a model: A model or simulation should only be as complex as is needed to accomplish the goal no more complicated. This is the golden rule of building a model or a simulation in science. Model the stuff you need, control the stuff you don't. I work on modeling human-robot interaction. We have models that treat the human as a big sack of potatoes (which is useful when looking at 'out of bandwidth' behaviors) - that's easy, treat them like a m, spring, and damper. Done. We have models that treat the human as a sort-of intelligent potato; these are good for modeling how the person behaves when you throw different, yet in the same neighborhood challenges to them. Etc etc Over-complicating your model for the sake of accuracy is one way that people don't finish their PhDs (the other, of course, being KSP). You can never win by making it more accurate for the sake of more accuracy, there needs to be a *specific* point for each layer of complexity. A cost benefit in other words. All of the 'more realism' requests are generally in the direction of 'make the game more challenging' which is *not* necessarily a positive thing, especially if it costs a ton of work to get there. Some things, like FAR and DRE could add alot to the game, in that you need to think quite a bit more about your design, but in general, the cost to the player is fairly low. Even though the whole 'Your Center of Drag is higher than your CG, your rocket tipped over' is a hard thing to learn, without hitting the forums. And requiring people to hit the forums to play the basic game is a *bad* thing. It discourages people, when you want them to enjoy the awesomeness that building and flying rockets is. Anything that discourages more people than it inspires is, in my book, a terrible design choice.

I've built a few rockets that used multiple SRB thrust limits like that, it's kinda fussy getting them all just right, but it works out pretty well. I mostly use them to deal with FAR + BTSM or FAR + early career, when 'too much thrust' is a *very* bad thing....

Even the center-crossfeed option is risky, since those decouplers need to be *dry* or you risk a catastrophic detonation. IMHO a modification of a Delta-IV type would be 'better'. On take off, run all three boosters 'hard', then scale back the center engine stage to keep an optimal thrust profile. Use the 'slow burn' time on the main stage to refuel from the two boosters. You can significantly reduce the fuel crossfeed rate, and you can 'shutdown' the transfer much earlier, as well as balancing across the load. I'm just not that convinced that it's worth it, from a dollars and cents point. The Saturn F1 engine *cluster* was under 0.2% of the fully fueled weight of the 1st stage, and around 30% of the *dry* weight of the stage - that's not that terrible. It also represented 5% of the total mass lofted to stage 1 separation. You can do something similar with the J-2 engine cluster for stage II. The J-2 cluster weighed ~9000 lbs, out of the total 1.500.000 for everything after stage I. That means that the J-2 cluster represented about 0.67% of the fuel to get up to stage I separation, or, about 32,000 lbs of fuel/oxidizer. LOX is cheap, and RP-1 is ~$5 a pound - running a back-of-the-napkin of 1:2.5 fuel/ox ratio, it works out to about 10,000 lb of RP-1 , or about $50,000 in fuel costs to lift the fricking Saturn V 2nd stage engine cluster. The reason we used fuel crossfeeding on the Space Shuttle was to recover the engines & pumps intact - they are the expensive part of the rocket. I am betting that this is part of the reason they are doing cross-feeding on the 9H as well, so that they can simplify the recovery process on the 9H main stage (ie, recover the center stage and get the biggest part of the launch cost back). Unrelated: Look up youtube videos for 'Delta IV on fire' for some bizzare 'real world' weirdness with rocket launches. There is a great one of a Delta-IV flying, with the entire lower rocket structure on fire. A good example of why you don't want to drip any fuel from your cross-feed connections.

One reason asparagus isn't used in 'real' rockets is this: The fuel flow need to run say, a Saturn F1 engine cluster is about 1/6th the flow rate needed to drive one of the main turbines at hoover dam - a *tremendous* amount of liquid, running in 2 distinct systems. Draining 2+ separate tanks, and keeping everything nice and balanced, at that depletion rate requires some really good (read - large and expensive) pumps and valving solutions. Further, the rocket needs to be able to switch between 'booster' and 'main stage' fuel sources without inducing so much as a bubble or 'boom' goes the rocket. The added cost in $$$, extra weight, and increased risk has made the gains just not worth it. Rocket fuel is pricey, but not *that* bad, compared to the cost of say, an engine (the biggest cost of which is the pumping machinery). It's the same reason we don't use variable-bell nozzles on all our rockets; yes, they are 'better' in theory, but the cost of implementing them is almost as high as what you will save.

Godamnit I have to sit on a master's defense committee tomorrow. No bags under my eyes and/or incoherence acceptable...

....nooooooooooooooooooooooooooooooooooooooooooooo....... Oh well. That means I won't get to play till Friday. Stupid Europe, with it's stupid being in a different time zone...

My wife thought my beard was 'vile' - woman has no taste in facial hair, was a spectacular Balbo.... hrmph...

Yah, I think that'll be the biggest 'problem' with TAC etc. It's solvable, though, by modding the contracts. So instead of spawning a mk I pod in orbit around the mun, it'll spawn a mkI pod, battery, and lifesupport container, sufficient to keep the kerbal alive until the contract expires. Will mean putting some effort into defining the 'spawning' routines, but will probably just mean pre-defining a series of hidden crafts, or some such. Would be cooler, anyways, to spawn a derelict craft, rather than just a pod or kerbal. Hmmmmmm

Derp? I think i screwed up the formatting on my previous post, so trying again....

I standardize. Alot, at least with lifters. My main sandbox game uses the following family: Sagittarius I is the most basic payload rocket used by the KSA. Simplicity itself, it consists of a single, powerful engine cluster capable of pushing 7 tons to a 100km perigee. The payload must have sufficient thrust to circularize at that altitude. The Sagittarius II is built around the short Sagittarius I, and is amplified by a triplet of hybrid boosters specially developed for the Sagittarius II project. The hybrid boosters, supplied by kerbodyne, consist of a long-burning, high thrust, SRB, as well as liquid fuel bunkerage sufficient to supply the main Sagittarius I engine for ~20 seconds of maximum thrust burn. This allows the Sagittarius II to place nearly 2x the payload in orbit as the Sagittarius I, for a minimum in extra complexity. The Sagittarius II can bring a 14 ton payload to a 100km perigee. Sagittarius III upgrades the main engine cluster and adds a powerful perigee kick interstage to the Sagittarius I lifting system, giving this lift body the ability to bring 15 tons to a 100km LKO. The Sagittarius IV is a stretched and enhanced version of the Sagittarius I, with a super-heavy new 3.75m engine from Kerbodyne. Flight profile, and overall efficiency is even better than the Sagittarius III lifter. The perigee kick motor has been upgraded to a full-fledged 2nd stage, bringing payload capabilities to 28 tons. The Sagittarius V is built around a modified Sagittarius IV core stage, with a booster triplet providing extra thrust at lift-off. The Sagittarius V(a) variant uses 3x heavy SRB clusters, while the Sagittarius V( uses strapped on Sagittarius I main stages, delivering fuel to the main booster via 9 heavy gauge transfer lines. The Sagittarius V( has a more efficient boost profile, however is significantly more expensive, nearly 2.5x the cost of an all-up Sagittarius IV. The Sagittarius V( is capable of lofting a 70ton payload to a 100km LKO, while the Sagittarius V(a) can place up to 55 tons in the same orbit. The Sagittarius VI is also built on the Sagittarius IV core stage, but is redesigned as a 3-stage rocket, boasting an all-new super-heavy main stage and engine. This new stage gives very similar performance to the Sagittarius V( but in more streamlined and cost effective package. The Sagittarius VI will lift 80 tons to 100km LKO. The Sagittarius VII is the all-up super heavy lift variant of the Sagittarius family. Built around the already massive Sagittarius VI core stage and using three modified Sagittarius IV main stages as boosters. The 2nd stage of the Sagittarius VI is significantly underpowered, even though it fits the most powerful 2nd stage engine available. The 3rd stage has been upscaled as well bringing the maximum payload to LKO to 140 tons.