paul_c

Its a horrible kludge but I've stuck something on for the sake of making the vehicle appear non-symmetric - for example, a thermometer, or a fin, pointing forwards. Then it makes it much easier to visualise which way its going and which controls will have the effect, no matter what the viewpoint you're looking at it. Also another tip, for example if you're descending and go sideways, is to use the SAS to turn to prograde (or retrograde), to see which is the new direction its heading relative to the surface/orbit etc.

Its not something as simple as, they're expiring due to going past their expiry date? Its easy to do a mission, which takes you say a few hours on the computer, but in that you've time-warped ahead several years to align some planets/etc.

Isn't there a science bonus for "doing" the research (I think its technically, transferring the data from the instrument to the experiment storage area on the Science Lab) whilst in that biome? For example, say you sent a space station to orbit Minmus. If you make a gravioli/gravity reading while over the lowlands, sending it to the lab (pressing the science beaker-shaped button) while over that biome, earns more science than if it had moved to another. Similarly, if the science lab were a base station on the surface, let's say on Minmus Greater Flats, an astronaut returning from an EVA with a surface sample from Greater Flats will earn more science than a surface sample from Lowlands, all else being equal (ie you've not already processed one, or returned one to Kerbin). This makes things a bit awkward to maximise science, you'd need to move your base station around onto the eg Lowlands to process the science to the max there. Without a science lab on it, a space station is limited use, but if it has crew on it (for "crew reports" - which count as science) or instruments eg thermometer, pressure, then it is useful for the contracts "gather science from space around xxxxx". Also if it has fuel, or you're lucky with its position; or put it in an orbit which covers all of the surface over time; it can do "crew report from space above Sector xxxx" contracts. Personally I've not docked to or expanded any of mine. But in theory, if it had lots of fuel, you could use it as an intermediate post for trips to-from the surface and/or returns to Kerbin too (given the right type of small lander/returner with the appropriate equipment).

In the above - if its a transfer from one circular orbit to another, it doesn't matter. But if its a transfer to an elliptical orbit (very different Ap and Pe) then its important to burn at the right time. Basically, you'd do this as a general rule: 1. Be in a lower, circular orbit 2. Burn prograde at the Pe of the desired orbit; or more accurately, imagine a line joining the desired orbit's Ap and Pe, where this line intersects your current orbit, burn then. That will raise your Ap to the same point in space as the desired orbit's Ap. 3. At the new Ap, burn to raise(/lower) the Pe as needed. (The above assumes the inclination is the same). Personally I'd always aim for at least 70250m as a 'parking' orbit, the reason being in KSP it assumes there is a boundary between space (where there is no atmosphere) and within the Kerbin atmosphere. Of course, in the real world, this is a much less well defined thing. Once above 70250m KSP doesn't include drag, and nothing else which could peturb an orbit is taken into consideration either, so you can effectively leave it there and know it will stay there. Maneouver nodes help - for a while, I got muddled with normal/anti-normal and quickly sketching out a planned maneouvre helps clarify.

The issue isn't really overall delta V - I dare say the 2 approaches are going to be very close there. BUT....put simply, once you are in orbit, you can use an engine of TWR 0.00001 to change orbit to...anything, really. Yes in practical terms you would want something a bit more spritely, but you don't need the TWR that you needed to get to orbit. (And yes, I know in the later stages of that phase, you can use a TWR<1 while completing the gravity turn to 70km, but you have a limited time to put the energy in, so it still needs to be a reasonably sized engine then). You can maximise efficiency by thinking about the different needs of each phase of the flight, and building a vehicle which is best/cheapest/lightest at that. For example: * first 1000 delta V - you don't need to steer, you're going straight up - use SRBs. Needs to be TWR>1 * to orbit (say 2500-3000 delta V) - initially needs to be TWR>1 (later bits if staged could be below though). Needs to be controllable and responsive * orbital maneuvering - can be TWR<1; doesn't particularly need to be fast/responsive at changing direction either So if you had a contract with a lot of orbital maneuvering needed, eg a big Ap and Pe, then it makes a lot of sense to "build" a satellite/probe as small as possible but with a decent fuel tank and a tiny engine (eg the Ant engine...only 20kg). In your case, a circular orbit of 320km won't take up that much delta V from LKO so its a bit moot though. (A really basic probe and a bag of fuel (the doughnut) gives you about 2400m/s delta V, which is more than enough for pretty much any changes and future contracts too). Another thing...for efficiency, NEVER make a plane change when launching the satellite (except for a small correction which might be required). ALWAYS launch precisely in the launch window (so the path of the orbit passes directly over KSC) and 'drive' the rocket in the right direction to be on the correct inclination from the outset. The 'cheapest' time to do that, is when you're going slowest horizontally, which is earlier rather than later in the launch. ie once you've just started the gravity turn, also look at the inclination and tweak the direction you're flying.

That's a really clever way to arrange staging - partly because it also makes the reduction in engine throttle, coincide with the increase as each stage's fuel is depleted. I tried it on a heavy(ish) rocket and it worked well.

What's the min PC spec for KSP? I have it on my desktop, which is quite new and was built for gaming; but I am wondering if its worth trying it on the laptop too. The laptop is nothing special: 8th gen i7 CPU, 16GB RAM, integrated graphics.

Mine can do 20+m/s on the flat: but its far more than "just" a rover. It was delivered using the big fuel tank in the middle and a small jet engine underneath.....and they still work, so it can fly too. Very handy if it tumbles or bounces into the air (just hit the throttle when its pointing up) or if one of its jobs is a little too far away, or the terrain too awkward to drive to. Does slopes well too, about 30-35 deg I'm happy with, maybe more if I'm brave. And it has a docking port on the back, it can move around and tow modules: Other features include 8x solar panels. It only needs 1 or 2 to keep up with normal driving, so I only put 1 or 2 up at a time. I've broken 3 but still 5 left.

As an example in pictures: 15 ton module is 'flown' like a normal vertical rocket to the known flat surface, note it will be deliberately landed a little away from the base, just in case it wipes it out. It landed and remained stable vertically, but with the planned placement of retractable landing legs, it was able to do a controlled 'fall' to horizontal. Note its about 800m away from the base. Note the edge-placed engines rather than central one, to allow docking port and expansion. The lander/tractor is sent out to collect it. The tractor is about 7 tons, the module is about 15 tons so needs a third pair of wheels (other modules can 'hang off the back' of the tractor and still be dragged around okay). The lander/tractor has it 'in tow'. Steering is reconfigured (both axles on lander turn same way; module's wheels don't steer). Nearly there Some amount of space is needed to swing it around but with the entire ice lake, no real worries With retractable legs strategically placed on all modules, and angling it from side to side, height above ground can be fine tuned to allow successful docking. This one went on fine. The previous two needed a nudge by a Kerbal on EVA. Note the "2-to-1" adapter on the right, this can be used strategically to align or vary docking height too, if needs be.

Wow there's a lot to work through on the above answer. Relating to landings, 1. Unknown terrain, non-precision 2. Known terrain, precision The first is when I'm visiting somewhere for the first time or exploring a new area of a previously visited body. I'd prefer to land on a flat bit, so some kind of hover/hold off landing/traverse sideways or away from the originally pinpointed spot is needed. Also, its possible to design and build a lander which can cope with (slight) terrain - I did a horizontal lander which happily landed on a 25deg slope. The second is when I'm bringing in another module for a base station; or doing a rescue mission; or a tourist mission where I've previously landed in that area so I know it. More recently I've gotten better at designing and handling landed modules "on the ground" so that they aren't required to land very near an existing base station (and possibly wipe it out).

My main concern was weight - a high TWR setup needs a big(ger) engine, if I can do it with low TWR then I can often use a lighter (and as a benefit, cheaper too) engine. And the weight saving of course has the multiple benefits of less fuel and less fuel tank dry mass. My latest rocket had: TWR: 1.22..................................................................SRBs only.....................599m/s TWR: 1.48.................................................................liquid 1st stage...........2595m/s TWR: 1.03 (40km altitude assumed).............liquid 2nd stage...........1834m/s and that lot got me to Minmus (elliptical orbit) and back.

Many thanks for the replies, I didn't realise gravity losses were quite such a high proportion - I thought a lot more was due to drag (so lower TWR made sense for that).

Recently I've been refining my rocket designs and have been using lower and lower TWR, around 1.2-1.4, with some success - they 'seem' more efficient and still stay flyable, whether this is my getting better at flying though I'm not sure. You obviously need TWR>1 for a take off (or a lander in vacuum) but the lower the better? Or is say an extreme example of 1.01 too low, because you'll effectively burn a lot of fuel hovering, instead of getting to where you need to go (above 70km for space). If so, what is the 'best' TWR, is there a mathematical solution or is it simply down to look and feel? Does it relate to drag vs desired altitude? In my mind, it makes sense that you'd not want too much for later on, because you want to put the horizontal speed element nearer to the Ap, which for efficiency is better to be lower (but above 70km to get out the atmosphere), that way you don't have a shutoff then restart - you'd want to continuously burn through the second half of the gravity turn? Otherwise why take a 6 ton 2000kN engine, when you could have taken a 3 ton 1000kN engine up there to be later thrown away? And for landers....I've aimed at TWR 3 (of the planet/body you're visiting), that way you don't have to do a slow down burn planned quite so far in advance; and have some 'power' to get control/get out of trouble etc, while still having a good control and you also know that 'hover' is around 1/3 throttle.

I normally look at SRBs for the first 1000 deltaV or so, because I know its going straight up; but also have at least one liquid rocket motor which can gimbal, so I have control. Tweaking the burn rate of the SRBs (and/or throttling down for the first stage with SRBs on) so the TWR is about 1.2-1.3 seems to be good for efficiency too, due to less drag.

In the end I did it a different way. I launched them separately. The polar orbit was for a very small satellite so I was able to build a rocket small, with marginal performance, which also flew reasonably well (I've had trouble with small rockets not being that controllable and ending up with a mishap). It still took 3 attempts. First time the 2nd stage did a flip - I recovered but not enough deltaV left to get anywhere near the orbit. 2nd try the final stage on the satellite was just too low performance, but it only took an upgrade of the fuel bag from a sphere to the sausage, to get enough performance. So the third time it worked out good. For the very large orbit, I tried a Mun assist but I muddled up my thinking. I entered an orbit in Mun then did an inclination change to retrograde, but on coming out of the Mun orbit later, it didn't come out as a retrograde Kerbin orbit. It might have done at Minmus, but not the Mun. Anyway, I was getting impatient by then so instead of trying from the start, I was able to get another Mun flyby to enlarge the orbit even more, then at a very large one, I did the inclination change from something like 20deg to 168deg and it wasn't massively costly; and I had enough fuel to alter the Ap and Pe to the contract. I'm interested in these unusual encounters etc so I'll be on the lookout for another like this, and I'll see if a Minmus assist can in fact reverse an orbit (still not sure!) and also Mun gravity assists are cool and save a little fuel. I also did a bit of research and found the formula to properly calculate what a change in the Ap/Pe of an orbit costs in dV, but its a horribly complex formula so I might need to spend a day with a spreadsheet!!!

I now have these two around Kerbin: As can be seen, they are very different. One is a polar inclination and the other is an elliptical orbit in and out of Minmus's radius. How would you (or wouldn't you) launch both satellites on one rocket? I was thinking - not sure if its too bonkers: * Launch into a POLAR orbit, approx the Ap and matching the orange orbit. Then detach the satellite, then tweak its inclination if needs be and raise its Pe with its own engine/fuel. Adjust the Pe of the rocket/2nd sat (pink orbit) to 70+km. * Wait for Minmus to come into the extended plane of the orbit, then burn prograde to extend the orbit out, intercept Minmus (not too worried about the Pe), burn retro to be captured in a wide Minmus orbit. * Do the inclination change to -167deg (the contract is for a RETROGRADE orbit around Kerbin) while orbiting Minmus * Burn prograde to leave Minmus and achieve a very large orbit in approx the right inclination in Kerbin. * Do a (hopefully minor) inclination adjustment, far far away from Kerbin * Adjust the Ap and Pe using Hofmann transfer.

I did think about this yesterday and its definitely something I want to try. I will need to do a little research and find out the angles and other numeric details; then find a good excuse to do it (for example, I think I have an M700 scanner which has done its work at Minmus, but need to check how much fuel is left in it).

Thanks, I was able to at least capture a broad orbit with the excess fuel I had. If I'd not had this, it would have been end of mission. It gave me a chance to do a bunch of science stuff at high orbit, its down now to about 80x200km (Ike is so huge, I was able to snag it on the retro burn and lower myself even more). I've parked it in a Duna orbit for now, there is a lot of science/data to process and the lads are working 24x7! (Or is it 18x4.3 since its Duna?) Thanks also for the mod suggestion - I am enjoying standard KSP and the challenges it gives at the moment, probably later on I'll get into mods.

I've been playing KSP for a number of weeks and now Kerbin-orbital and Mun/Minmus trips are consistent, after a run of bad luck trying to land on/return from Mun. So I gathered a bunch of Duna/Ike contracts and the time has come to do the trip. I'd been twice before, but they were not-too-serious attempts with a big overpowered rocket and a bit of luck too. I transmitted a little bit of science data, not much, then got "lost in space". So on my third trip I'd done a bunch of planning, and was taking an 8-pax station with a science lab and some Kerbals. I'd done a few tests on electrical demands (it seems 8x 1x6 solar panels is a good rule of thumb to keep up with a busy Science Lab) and I understand comms required transmitting power too. I knew the timing would be critical so I read up on the angles etc and made the trip, after waiting a number of days in Kerbin orbit (and was able to check out the science gear too). I got a burn which took me to an encounter with Duna but the Pe was 18Mm, and the orbital insertion burn was ~1000dV. The specs say it ought to be closer to 250. It was so finely balanced when & how much to do the outwards burn I was afraid to fiddle with it too much. I am guessing some kind of mid-course normal/antinormal or radial in/out would have lowered my Pe right down?

I haven't killed a staff Kerbal for a while now - I'm taking the realism seriously and trying to keep them alive. I did kill a tourist recently - controller went dead and the parachute didn't deploy, even though they'd landed on Minmus and made it all the way back, including the re-entry. That was unlucky. I kinda feel partially responsible. I did build a massive rover truck thing, with a science lab on it, loads of structure, big motors too, it could do about 40m/s. It also had massive ground clearance - unfortunately not quite enough though, and the chassis was about neck height. I pressed the wrong button, or they walked in the way, and it hit them. Amazingly they survived although I suspect he'll have a headache for a little while. I had one guy who was stuck on the Mun for about 2 months. Ironically, when I eventually rescued him, the skyline after re-entry was a beautiful twilight scene with a full moon, but he didn't want to see it and says he doesn't want to go back.

It depends what you want to achieve, I guess. If you like to delve into a programme of testing various rocket designs, then that's a brilliant way to spend time in KSP. I've done similar. Sometimes the focus isn't so much the actual rocket, but the destination or the payload - for example in career mode, you might have a satellite to launch with an unusual requirement. Or have your own personal goals of eg "getting to the Mun" or elsewhere. Me personally, I like building/launching satellites and controlling the costs as much as possible on them. So I'll spend an amount of time slimming down the rocket design, looking for the most efficient orbital transfers in dV, etc etc I'll spend an amount of time on the launch rocket but its one phase of a mission with a number of phases. If its a new or very different payload, which means one of my previous rocket designs isn't working out so well, I might end up doing say 5 test flights before I'm happy with it. I don't mind doing 5 flights and looking at the pertinent figures like TWR, dV per stage, etc. But I'll look at external guidance too, rather than doing say 20-30 flights to find for myself the 'best' TWR.

Phraseology - "Tried and tested" is figurative - I don't have links to scientific papers on it (although I dare say they do exist, since rocket science is an academic profession). Its KSP's conventional wisdom, which is based on the laws of physics, which is what KSP is (with tweaks here and there) based on. Another aspect I forgot is payload/crew comfort and Max-Q considerations - of course, these don't exist in KSP but do in real life - this is why when demonstrating new airplanes they don't do barrel rolls, although they could.

Didn't the actual space shuttle do a 270deg turn once it was done with its re-entry (and some S turns in there too). With a 270, you're basically flying a crosswind, downwind and base turn like an airplane would approach a runway. It gives opportunities to adjust and line up (in position, angle to the runway and glideslope/appropriate height) by extending or contracting each leg or turn. I believe a similar thing is done by airplanes with an emergency of variable/unknown length, for example if they are diagnosing something or a developing medical emergency - they will circle the chosen airport above.

My (limited) understanding, is that: * TWR must be >1, otherwise its not a rocket and/or won't go up like a rocket * Anything above 1 means it accelerates. Since its flying in the atmosphere (initially) then drag will need to be overcome (and its losses are proportional to v2) * The bigger the lever arm (ie like a dumbell, the weight at the top and bottom - don't worry about the bottom the engine and sloshed fuel will be there) the more control. * The larger the TWR the more control too (but we don't want excessive TWR due to drag) * Fins help with control/stability but add drag and weight So that's why there's an "ideal" value for TWR, its not arbitary its a tried and tested performance figure which is a good balance of control and performance/efficiency.

Just had another one with a distant orbit of Kerbin, this time they asked for 24x16Mm and inclination 11.2deg. I aimed for the Mun, swung by on gravity assist and had a Kerbin orbit of 75x12 (ie beyond Minmus). I was also able to line up the Ap to not too far from the AN/DN of the desired orbit. This meant that doing the plane change cost buttons (about 24dV). Then it was a case of raising the Pe while far out at my 75Mm Ap (I was worried about comms signal, but it worked out okay), then burning retro to complete the contract by setting the desired Ap. Basically a bi-elliptic transfer but with a Mun assist to save many dV from its first 2/3 burns.