Rusty6899

That's pretty much what I assumed, but for that to be true, and for the delta-V map to be accurate for both directions, it would mean that your circularisation burn around your new destination would be the same regardless of your origin. If I was to use the example of a return trip to Low Jool Orbit from LKO. It takes 950 m/s to leave Kerbin's SOI (I assume that is what is meant by the figure between LKO and Kerbin Intercept.) It takes 965 m/s to encounter Jool (I assume this refers to an encounter with a 150 km periapsis as that is the value the map gives for LJO so a 150km periapsis would be the most efficient encounter). It takes 2630 m/s to circularise to LJO. This is what I have always assumed the delta-V map denotes, however when considered in reverse, although I accept that the TOTAL delta-V is the same, each individual value should not be. If the map is read in the same way in reverse... It takes 2630 m/s to leave Jool's SOI. It takes 965 m/s to encounter Kerbin. It takes 950 m/s to circularise to LKO. This makes no sense though, as a LJO circularisation burn from a Jool encounter HAS to take more delta-V than a burn from LJO to leave Jool's SOI, because it is effectively the same burn in the opposite direction with the addition of the delta-V required to achieve an initial orbit from an encounter with Jool. The same has to be true of Kerbin escape/circularisation burn.

I was wondering if anyone could tell me what exactly is meant by "intercept" on a delta-V map. I had always assumed it indicated the point at which you would encounter the target object. For example, from the delta-V map I use, it takes 950 m/s to get escape Kerbin from LKO. It then takes 965 m/s to get to Jool intercept. I was wondering if this refers to a Jool encounter or to get into an elliptical orbit about Jool with a low periapsis and apoapsis close to the edge of its SOI. I was thinking that surely if it does refer to an encounter, then there is no way the map could be correct in either direction. It would have to take more delta-V to get to LKO from a transfer from Jool that it would from Duna after the encounter was made, as you would be travelling faster coming from Jool.

Basically, when in orbit, the path of your orbit can be be defined by your periapsis and apoapsis, along with the mass of the object you are orbiting around (there are other constants involved but these three are the only variables). This means that if you are at a 100km periapsis, your velocity at periapsis will determine the size of your apoapsis (at any point in your orbit the speed and direction are enough to calculate the trajectory of your entire orbit. It is simplest at apoapsis or periapsis as you will be travelling perpendicular to the object you are orbiting). It means that you can calculate how fast you would need to be travelling at periapsis to achieve any given apoapsis, so you can work out the amount of velocity that you need to "add" to your current velocity. This is delta-V. In an example where I have plucked numbers out of thin air and no maths is involved because I need to leave for work in 15 minutes and I don't have time. Suppose you are in a 100km circular orbit around a planet and your orbital velocity is 4000 m/s. There is a moon, in a 100,000km circular orbit around the planet, that you want to encounter. You calculate that a velocity at a 100km periapsis of 9000 m/s will give you an apoapsis of 100,000km. This means you need a delta-V of 5000 m/s to encounter the moon. In KSP all the delta-V requirements can be obtained from delta-V maps, which people have made, so you don't need to do calculations on this front if you don't want to. It helps to have some appreciation of it, though. In addition to knowing the delta-V requirements, you also need to know the delta-V that your ship has. This is generally calculated for each separate stage and is given by the equation... dv = Isp * g0 * ln(m0/m1). Unless you have certain mods installed, you will need to calculate this yourself. Isp is the specific impulse of your engine (can be seen in the VAB when you select it), g0 is always 9.82 m/s^2, m0 is the total mass of your rocket in at the beginning of a particular stage and m1 is the mass of your rocket at the end of that stage. Isp and mass are in seconds and tonnes respectively (as they are given in KSP).

That was pretty much what I did on my first trip to Jool (or planned to). My first mistake was to get myself into a retrograde orbit, which pretty much eliminated my chance of landing on Laythe (I wasn't particularly good at accurately setting up intercepts at that point. I also struggled with encountering Bop. Firstly, a prograde orbit is pretty important. It lengthens the duration of encounters, and makes a Laythe landing much easier. I doubt the Delta-V requirements will be anything remotely like 1000 between moons if you only plan to encounter, rather than orbit... more like 1000 for the combined manoeuvres if you make them at a low Jool Periapsis. Look at a delta-V map, the Delta-V requirements between moons are equal to the difference in delta-V required to intercept from a low Jool orbit, so between Pol and Bop it is 2500-2430 = 70m/s. This assumes you have a Jool periapsis at ~150km and apoapsis at Pol's orbit at the start of the manoeuvre. As long as you can get to an eccentric, prograde Jool orbit with about 4 tons of fuel, a nuclear engine and a total mass < 10 tonnes (plenty of spare mass for a light landing set up for Laythe) you'll be fine. The best order, by far, to do this in is the way you have outlined, outermost > innermost, in order. You would be wasting 100's of m/s of delta-V to do it any other way. The only other thing I would consider is how close you get to Tylo, you don't want to end up getting a massive gravity assist and ending up leaving Jool's SOI. I can't say I am too sure about how gravity assists work, though so I'm not sure how to approach it to ensure a close encounter without it affecting your orbit too badly.

I quite often find that with larger rockets, my crafts are fairly structurally unstable. Sometimes I get strange failures where a fuel tank will detach from both radial decouplers and Stability Enhancers, while still on the launch pad. I'll get the odd mid-flight failure where I assume there is a structural failure leading to a large explosion. I quite often find that for more slender rockets, my SAS tends to encourage a resonance in the rocket, leading to it snapping. I guess that's more of a obvious design flaw, though. Basically, the things I am interested in are roughly how the failure of connections between parts are calculated (no need for precise equations, I was more wondering which parameters it considered; velocity/acceleration/mass etc/properties of the part). Also I was wondering how connections between struts were modelled. Is it simply modelled as one part connected to another, or does it take into account the exact position and angle of the strut? Also, can too many struts cause a more precarious rocket by restricting motion at all?

Serratus That's pretty much the point I was trying to get across. I don't like the idea of having it built in as a major game mechanic, but I do think that there should be a greater impetus to encourage certain players to colonise.

Personally, I don't think that anyone would describe themselves as "anti-colonisation". The biggest argument on the subject is how colonisation affects the mechanics of the game. The OP is suggesting that the game should incorporate a dedicated system for colonising planets, whereas I, and a few others who have replied, feel that the game could be altered to allow players to benefit from a colonisation project, but it doesn't necessarily need to be specifically catered to. I like the ideas you have put forward about needing to deliver specific components to a space base, as it does provide an alternative to levelling, which I don't think is in the spirit of the game. I do think, however, that even with those features, it is still a case of colonising, for its own sake, which is all good and well, but I think that there should be reward system for people who want to play the game that way. I think that the resources of money, science and reputation should be designated as three ways to "succeed" at the game. Succeed with science by performing experiments, reputation by exploring and money by colonising (and mining). This would mainly be implemented with the ordering of the technology tree so that players could choose their appropriate path (At the moment I would say the tech tree is generally split into rocketry, spaceplanes, science). I also think that the implementation of these methods of gameplay may be able to reduce the need for difficulty levels. Newer players would benefit from being able to perform more numerous science experiments on Kerbin, Mun and Minmus, to achieve a reasonable amount of progression before they are ready to go interplanetary, intermediates would have the ability to explore the Kerbol system relatively early on to gain a good level of fame, experienced players would be looking to make return trips with valuable resources, which would make them money. All it requires then, it to have a slight incentive in terms of progress speed to choose the harder options and you have an effective yet diverse game mechanic.

I think that bases could be improved by letting players construct ships and base components out of parts that they have already landed there, and fly them with fuel that you have brought there (no messing about with docking ports), although I am not totally against the idea of fuel being mined. I think that gets the balance right between making the game into a colonisation strategy game (which I think would have a very flimsy gameplay structure) and the limited functionality of bases that we see now. I would actually prefer that if mining was done, it would be more of a case of bringing valuable resources back to Kerbin for money, reputation and science. The challenge would be in producing crafts that could return significant amounts of resources back... So you can return from Eve, eh? Try it now with 10 tonnes of Blutonium in a storage tank. This would also give you a significant reason to build bases on other planets, as you never know when a contract is going to come along asking you to bring back a load of Duna dirt. You could consider the parts you have already in your base and just take along what you need.

I will generally get a feel of how the mission will be undertaken; how many stages do I think I will need? which engines will be most appropriate for each stage? how many bodies will I be landing on? can I reuse the lander? etc. When these questions are answered I turn to my spreadsheets to ensure I have a 5-10% excess in delta-V budget for each stage (more in an interplanetary stage where I may not have a fully equatorial orbit, or landing on, say, Duna, where I am unsure how much of the breaking will be done by parachutes and how much by engines). For complex procedures (e.g. where I will have to assemble landers out of several sections in orbit, or if I am using parachutes on a fairly heavy lander, I include a testing stage to ensure I don't end up on the other side of the solar system with a strut preventing a docking port from opening, or with no way to land a craft). I would say it is a case of Concept Design, Detailed Design, Testing. I definitely need to implement a structural design stage within the concept design, though, as I have fallen foul a few times. It's frustrating when a complex mission is designed well, but it all fails because your craft falls to pieces on the launchpad. I haven't really designed a space station yet. Most of what I have ever had up there have been little more than fuel tankers. Same with bases to be honest. I lose my enthusiasm for building them after I land a couple of structures and transporters to carry them about.

I'm getting into the swing of building efficient craft at the moment. I had had enough of watching a 0.2 fps slideshow as my juggernaut, 600-part crafts struggled against lag with barely enough juice to go interplanetary. I learnt the delta-V equation and made a spreadsheet to calculate the minimum amount of fuel needed for a stage with a given engine/mass etc. From then on I have been a lot better. I managed to get to Mun and back with a 33 ton rocket, and to Duna and back with a 220 ton rocket. Initially I had to learn to dock, simply because I was so bad at making efficient crafts that I needed to refuel as often as possible. My first return trip to Duna consisted of sending up countless rockets up to a create a fuelling station (it probably took about 5 launches just to get a couple of orange tank's worth of fuel in there), fly it to Duna, then repeat again for another fuelling station in LKO and finally send a massive ship, which after two refuels, managed to limp back to Kerbin. I haven't actually done any docking in quite a while (I have been trying to design missions so they don't need to), so I'll probably be pretty rusty at it when I try again. I'm currently designing a ship to complete the Jool-5 challenge. It has the required specifications (or thereabouts), but it is a structural nightmare, which is cripplingly embarrassing for (in the rather grandiose terms that my degree certificate uses) a Master of Civil Engineering. I'm reasonable at achieving encounters. What really surprised me, though is that I had never heard about efficient ejection angles until a few weeks ago. That certainly helped, and generally playing the game tends to give you an appreciation of the principles of orbital mechanics. I still haven't used any mods yet. I'd quite like to try kethane, deadly reentry and a few others. I would say that I have learnt how to play the game well, but that just means that I need to find some harder challenges.

I can't imagine many people being condescending to players trying to learn the game. It took me a long while before I became reasonably accomplished and I'd be happy to help anyone who was trying to familiarise themselves with the same concepts. The only thing that I think could be a problem in terms of self-righteousness is the whole "is MechJeb cheating?" argument. I have to say I have seen a couple of people on the forums being a bit disparaging towards MechJeb users. I think most of the community will rise above it though.

While I think that budgets will make it interesting, I think that they have to be implemented the right way. The fact is that there is going to be a massive discrepancy between new coming players and more experienced players. I am sure that I could fly a return trip to almost anywhere in the Kerbol system for the same cost as a newcomer's first Mun landing. That isn't meant to be condescending, it's just that I learnt almost everything I know about space flight from this game and my first attempts were extremely inefficient and would have cost absurd amounts. That said, a more experienced player shouldn't have to have their budget cut so tightly that they have to fly suborbital for the first 20 missions. Personally, I think that contracts should be the way forward (although not the exclusive method of mission choice). You get given/request a destination (reputation would determine which are available) and are given a budget based on your destination, tech tree progress and game difficulty setting (maybe even given access to one or two parts from further up the tech tree, although that depends on whether you will buy-as-you-build or have a part inventory I doubt it would be possible with the former). You could then either perform the mission directly for less than the budget, or visit the destination as one part of a multi-target mission, supplementing the mission budget with your own funds to cut a bigger profit. I think that rather than preventing you from adding more boosters, budgets will probably just prevent you from using large numbers of the more expensive parts as the game progresses.

I get that, I was talking specifically about planetary returns, where you are forced to build a fairly substantial rocket. Isn't a nuclear engine a pain to land on the Mun? I would have thought that a NERVA is a bit excessive as well. I'm pretty sure you could build a lighter design using 2-3 stages and smaller parts. The thrust to mass ratio is generally only important for ascents/landings (Delta-V is also very important there as well), but TMR can also be important for interplanetary transfers where longer burns can be much more inefficient (in so much as the period of your burn is proportional to TMR).

They are useful for building Single Stage To Orbit space planes. Basically, they can switch between a very high level of fuel efficiency in an oxygen atmosphere by taking in oxygen as a jet engine, and the functionality of a reasonably efficient rocket engine for when you are in the upper atmosphere/space. Normally for space planes (although I haven't built many so I am not an expert) you have to have a mix of jet engines and rocket engines to reach orbit, but the RAPIER lets you get a 2-for-1 balance with one engine.

NeoMorph I think the whole "Moar Boosters" idea is far overplayed. To perform a return trip to another planet, you need to look at a delta-V map and think "how light can I make my return stage to satisfy the Delta-V requirements?" Next, look at the planet you are going to and think "what is the lightest I can make my landing/ascent stage to lift my final stage up from the target planet? Can I aerobrake to save weight? How much thrust do I need for this planet to ascend for a TWR of 1.7-2?" Then do the same for the interplanetary transfer and finally for the ascent from KSC. If you build a rocket without taking these things into consideration, you are almost certain to run out of fuel by the time you get to your target. By then, adding moar boosters is unlikely to do you much good. I made a return trip to Duna, without refuelling, with 89 parts, 45 of which were used just to get to LKO.

I mean to say that designing a rocket capable of going to, say, Duna and back is harder than designing one to land on pretty much any body in the system (although I haven't attempted Tylo yet, I'm guessing that's not too easy). Quick save generally makes the flying part of the game fairly straight forward- if you have enough delta-V then obviously a return to Kerbin is no trouble.

Getting to Eve isn't that difficult. It's probably easier than Duna. Bigger SOI less delta-v needed to intercept and a much thicker atmosphere for aerobraking. Jool is harder by comparison due to the greater delta-V requirement. The fact is that there is nowhere in the game that is very difficult to get to. Getting back is the challenge. That is why return missions have to be the best way to earn rep/science.

kBob Don't worry too much about thrust. It is rarely important. As long as your thrust/weight ratio is above 1.7 you have enough thrust to reach orbit (after that thrust is almost irrelevant... almost). It is fuel efficiency that is the main concern. That is normally gauged by the Isp of the engine you use. Mainsails have a lot of thrust but terrible fuel efficiency and they are heavy. Try a lighter rocket using a more efficient engine, such as an aerospike for the first stage (you may need 3/4 of them depending on the mass of your rocket, but it could be done with one). Mass and Isp are the two main things you need to keep an eye on.

I think that the game has several key challenges to meet but, if it does, it could be the best game of all time. Firstly, the complexity of the game. This game has taught me so much about orbital mechanics and rocket design. It lead me to learning about the motion of variable mass systems, orbital energy and the less-is-more elegance of Tsiolkovsky. I love the game, and I love that it is difficult, but that in itself poses a huge problem. Squad need to produce a final release that is accessible to newcomers, and therefore will require a career mode that allows a new player to rattle off a large number of sub-orbital flights while picking up the nuances of rocket design, staging and flight. At the same time, all of the feedback they are getting, or the vast majority of it, is from this forum, from dedicated players who are now demanding new challenges and a harder difficulty. Squad have an incredibly difficult balancing act to satisfy both new coming and existing players. Suppose you manage to reach tier 3/4 of the technology tree. A newcomer would have struggled their way there with countless flights, yet an experienced player could be there in a handful. Players will have to work within a budget, but it seems to me that any budget that enables an inexperienced player to reach the Mun would be enough to let a battle hardened Kerbanaut get to Eeloo and back twice. Obviously there could be difficulty settings, but that goes against the idea of everyone "having the same experiences"; a view that I respect Squad for having. Secondly, resources. It isn't that the game needs resources to be great, it's already great. The problem is that the game is still in development and I have been everywhere I want to go and done everything I want to do (with the exception of a return trip to Eve and a Tylo landing). Resources seemed, to me, to be the natural progression in the development of the game. I really looked forward to mining for rare alloys in the far corners of the solar system and bringing large quantities back to Kerbin for riches and glory (...and science). I looked forward to having a base on Duna where I could drill for improvised propellants and chuck together a makeshift rocket out of the assortment of parts that I had landed there. I looked forward to whisking a sample of Blutonium-239, that I had clawed from the guts of Pol's deepest canyon, back to Kerbin and being rewarded with a shiny new RTG for my troubles. It seems like these may not be implemented, which would be tragic, although I sympathise with Squad because it is difficult to see their incentive for making such a huge development, when most of the people asking for it have already paid for the game. The third problem, is that I payed £12 on a Steam sale for one of my favourite games of recent years, yet I expect so much more from the game, because of how much potential it has. I am not satisfied with one of the best bargains I have ever received.

Maybe it would be better if you just needed a satellite around the parent planet of the body you are on, so you wouldn't need to have satellites around all the moons. I really like the idea though, there should definitely be incentives for players who want to build infrastructure around the solar system. That's why I would have liked to see mining in the game and large scale resource returns, but I digress.

Is that true? Can't say it makes a huge difference to be honest.

Here's an example. From a low Munar orbit, I want to land on the Mun and return to Kerbin in one stage. According to the Delta-V map I have, I will need 2350 m/s. (I will round it to 2500 for a factor of safety). I choose an LV-909 engine, as I need landing legs to fit on it, it provides sufficient thrust for Mun landing/take off and has low mass with a decent Isp (390) in vacuum. So far my rocket is designed to have... Mk 1 Lander Can, 3 Microstruts, 3 OXSTATs, a TR-18A decoupler, a Mk16 Parachute and the LV-909. M_total = 0.66 + 0.045 + 0.015 + 0.05+ 0.1 + 0.5 = 1.37 tonnes m0/m1 = EXP(2500/(390*9.81)) = 1.922 m1 = 8*1.37/(9-1.922) = 1.548t m0 = 1.548 * 1.922 = 2.975t mass of fuel required = 2.975 - 1.548 = 1.427t Therefore an FL-T200 and a FL-T100 can be used. Finally, double check this with the Tsiolkovsky Equation... dv=390*9.81 * ln(3.0575/1.5575) = 2580m/s --------> The values of m0 and m1 are slightly different because the mass of fuel and fuel tank are slightly higher than the calculated minimums.

Firstly, choose an appropriate engine for the stage, based on thrust requirements/delta-v requirements etc. This comes with experience, but can be estimated reasonably well. Secondly, add the mass of all the parts in the rocket (except the fuel tanks, because we don't know how much fuel we need). Call this M_total Calculate the required m0/m1 = EXP(dv required / (Isp*9.81)) calculate m1... m1= (8*M_total)/(9-(m0/m1)) -----> This only works for fuel tanks where full/empty mass ratio = 9:1. Replace 8 with 4.35 and 9 with 5.35 for the other two tanks. Calculate m0.... m0 = m1* (m0/m1) m0 - m1 is the minimum required mass of fuel for the stage. You may want to add a factor of safety of 1.1 or 1.2 to ensure you have enough, but I have used this method a fair few times and never came up short.

At the moment, if anything, I would say that the RTG's are too advantageous. Obviously they can't compete with the solar panels for e/t, but that isn't the biggest concern for most missions. A single RTG can provide enough power to operate any command module and an SAS module simultaneously, meaning that unless you are transmitting science data from a short encounter, you are unlikely to need to worry about the electric power in your vessel (even then, I think you may be able to spam the perform experiment/transmit data buttons and it will send data when power becomes available). Does anyone seriously use Ion engines? The mass of the RTG is also unlikely to affect Delta-V in any significant way, even for very small probes. The obvious advantage of the RTG is its ability to work in darkness, meaning that it can have a significant edge on solar panels depending on the mission. I do, however, agree with the OP in certain ways. In my opinion the RTG, in the final game, should be a very high cost item, to be used only when it is critical for the mission. This would be best implemented by allowing solar panels to be sufficient for electric power gathering for solar distances up to Duna/Dres. For Jool/Eeloo/new outer planets, the RTG should be a necessary investment (this also helps to develop a logical progression of exploration to new players). A further use could be created by the ability to collect and transmit "night time" atmospheric conditions on bodies, where the RTG's would again be beneficial over panels. I also think that a finite, albeit very long, lifespan for the RTG would help for game balance and realism. In the future, if I am planning a Jool mission, I want to have to consider whether it is more cost effective to have 2 tonnes of Solar panels to sustain my electric power needs, meaning that I will need an extra ~25 tonnes of fuel/engines to conduct the mission, or use a hugely expensive RTG.

I think that the main problem with the current system is that it makes asparagus staging too beneficial. I generally use asparagus staging for almost all my ascents from Kerbin, with a 6x symmetry (the engines/fuel tanks I use are determined by the mass of the payload). Personally, I don't see that as too much of a game breaker, but having started to plan a return mission to Eve, it becomes apparent that a ridiculously wide craft, utilising a large number of engines in an asparagus stage, is the most sensible method to use. I think that the aerodynamics have to be tweaked to prevent hugely unrealistic rockets from being the go-to option for ascents from atmospheric bodies. I don't necessarily think it is the most pressing developmental concern. I would rather see finances and resources being effectively implemented (... I know), but I do envisage a final game with a better aerodynamics system. In my opinion, the aerodynamics system should be one of the last things implemented. I think that to change it now would be akin to adding a coat of gold paint to the Bentley at the expense of the engine.