AbacusWizard

Specific impulse (I_sp) isn't exactly fuel burnt per second, though it is closely related. The key idea is that the engine's thrust (in, say, newtons) is proportional to the rate at which fuel is burnt (in, say, kilograms per second)--burn fuel faster, and you'll get more thrust. "Proportional" just means that we can write the thrust force (F_thr) as something times fuel consumption rate (dm/dt): F_thr = ___ x dm/dt That something, that constant of proportionality, has units of m/s, meaning it's a velocity--if I remember correctly, it's the velocity of the exhaust that shoots out the back of the rocket engine. That means that the faster the exhaust shoots out, the more efficient the rocket is. F_thr = v_exh x dm/dt Divide both sides by the fuel consumption rate (dm/dt) and we get v_exh = (F_thr) / (dm/dt) In other words, v_exh is the ratio of thrust force to fuel consumption rate--that is, newtons of thrust per kg/s of fuel consumption. In any sane world where all engineers use the metric system, we would call that ratio specific impulse (I_sp). However, in our world, some engineers insist on using other units of measurement for distance, meaning that engineers in different countries would get different values for v_exh. To avoid confusion, it is traditional (on Earth and, apparently, on Kerbin) to divide v_exh by Earth's gravity (about 9.8 m/s^2 or 32 ft/s^2) to get units of seconds; that way it doesn't matter what measuring system you use as long as everyone is measuring time in seconds. So that's I_sp: the exhaust velocity (or ratio of thrust to fuel consumption rate) divided by gravity. That means if you want the actual ratio of thrust to fuel consumption rate, look up the engine's I_sp and multiply by about 9.8. - - - Updated - - - Some other fun math stuff to try out: Check the current mass of your craft. Check the thrust provided by its engines. Use these to calculate the acceleration it's capable of, and then read the display on the acclerometer (you did include an accelerometer on your craft, right?) to see if your calculations are correct. Read up on the Tsiolkovsky rocket equation if you haven't already. If you've taken calculus, see if you can use the idea of specific impulse (and perhaps conservation of momentum) to figure out why it works. Whether you've taken calculus or not, you should be able to use the equation ot set up a spreadsheet where you can type in your craft's mass, how much fuel it's carrying, and the I_sp of its engines, and instantly get feedback about how much ∆v it's capable of. Use the formulas for force of gravity (at a long distance, not just F=mg) and centripetal force to figure out how high and how fast you'll have to be for a perfect kerbosynchronous orbit--that is, a satellite that's always directly above the space center (or any other fixed point on the equator). Try a suicide burn! Suppose you have a rocket that starts at rest (relative to the planet surface) some very large height above the surface of a planet. The most efficient (and most terrifying) way to land is to freefall (AAAAAAAA! says mission control) until the (very precisely calculated) last possible moment, then set engines to full throttle and slow down just in time so you come to a complete stop at ground level. Try to construct a formula that can determine (given mass and radius of the planet, initial height, mass of the lander, and engine thrust) exactly when you should "hit the brakes" and transition from freefall to full throttle, then test your formula experimentally! (Suggest trying this with an uncrewed probe; your first attempt will almost certainly crash catastrophically--and then you get to try to figure out why!)

I'm quite fond of Minmus. Very easy to get to; weak gravity, so orbital maneuvers, landings, and takeoffs are all cheap; a variety of interesting landscapes to explore (flats, slopes, and plateaus); and minty-fresh flavor. Also the flats are excellent runways for landing and takeoff of spacejets! When I have the infrastructure for it, Jool's moons are fun to play with as well. Laythe is a great place for a beach resort with amazing night skies.

Depends on where you're lifting it from. I recently installed Karbonite and set up my first mining base on Minmus, where the gravity is so low that I can extract karbonite from the ground, use a big lander to pull it up into orbit, dock at my orbital refinery, and convert it all to rocket fuel. The lander is big enough that each round trip fills a large Kerbodyne tank with fuel, and then I pull a small amount of that back into the lander to power the next round trip. (It really helps that Minmus gravity is so weak that I can use super-efficient atomic engines on the lander.)

I generally start with a specific ability (or list of abilities) in mind, and consider what parts would be needed to accomplish that ability. Sometimes I sketch out a general design on paper (especially for large orbital stations and surface outposts); other times I just grab those parts in the VAB and start mashing them together. Once I've assembled the necessary parts, I start considering how it's going to get to where it's going.

It seems strange to me that the folks who claim that gender in video games isn't important are the ones who get the most angry when anyone suggests introducing more gender diversity to video games.

I'd also like to be able to see what planets a given kerbalnaut has landed on during the current mission, i.e., not "logged" back at KSC yet. For instance, suppose Doodtron Kerman is currently stationed at Mun Orbital Command, and has definitely landed on Mun... but I can't remember if, prior to that, he was also at Minmus Orbital Command and landed on Minmus. It'd be nice if I could find out before returning him to KSC.

I like a mixture. Some realism is important because I like the notion of learning about real-world astrophysics and engineering as I play, but at the same time I really enjoy messing around on Minmus and the moons of Jool.

Perhaps a badge on the spacesuit torso or an insignia on the helmet could be used to signify different jobs? It'd be a nice way to tell what a given kerbalnaut's specialization is just by looking closely, and wouldn't make the spacesuits look significantly different.

Perhaps you should take a cold shower. This isn't a romance simulator.

I'm in favor of crewed/uncrewed; I already use those terms anyway when describing my spaceships. (The only problem is that when spoken aloud it sounds like "crude," but in written text that's not an issue.) I notice a lot of people defending "manned" as gender-neutral by citing a dictionary. Do you realize that dictionaries are descriptors of language, not authorities of language, and that they are imperfect descriptors as well? People use words to convey meaning, and other people observe those words and infer meaning; in an ideal case, the conveyed meaning and the inferred meaning are the same, but this is not always the case. Know your audience. You may use "manned" in a way that you think is gender-neutral, but are you sure that the reader and/or listener understands it (both consciously and subconsciously) as gender-neutral? Proposed experiment: describe a spaceship to the test subject. Include the word "manned" in the description, but do not say anything else about the spaceship's occupants. After the description, ask the subject various questions about the subject's thoughts regarding the occupants, including what gender they are. Repeat this test for many subjects, but for half of the subjects (chosen randomly), use the word "crewed" instead. Run statistics on result to determine if use of "manned" versus "crewed" correlates to any differences in subject's assumptions about occupants' gender. Anyone want to try this out? Until you do, please don't make claims about "manned" being gender-neutral.

That makes a lot of sense. Sure, obviously they're not going to work due to the lack of oxygen, but perhaps what we simply see as "Run Test" in the right-click menu translates in-game to more detailed investigation of exactly what else doesn't work in that situation and why. It's a little like, say, running accelerometer tests from a parked plane in various biomes on Kerbin's surface. We already know what the accelerometer's display is going to be, but in-game the little green scientists are presumably getting more detailed information than what we're seeing; we just simplify all of that to "science points."

For spaceplanes I still just use Mk1 or Mk2 parts, but I've been finding the Mk3 parts very useful for huge interplanetary starships. The cargo bays are nice places to store landers, probes, etc., and the connector parts (Kerbodyne to Mk3, Mk3 to Rockomax, etc.) allow structural connections that double as fuel storage. Note how the different sizes of parts in the engine nacelles connect: The large cargo bay fits a science lab and a compact three-person lander:

Come on, astronauts; what are you afraid of? We're pretty sure that test flight 122 is going to work! P.S. our testing program has run out of funding, so YOU are test flight 122.

For me, in the long run, absolutely cheaper! I tend to focus on huge reusable interplanetary ships, and once I have a few of those in play, my largest expense is sending up colossal tankers to refuel them. With resources, I'll be able to keep reusing the same tanker over and over again. I've recently been trying this with the Karbonite mod and it's working quite well so far. The infrastructure includes: • one karbonite extractor station on a plateau on Minmus • one karbonite refinery in low Minmus orbit • one tanker (four Kerbodyne tanks with atomic engines and maneuvering jets) docked to the refinery • two landers packed with karbonite storage tanks The extractor mines karbonite and pumps it directly into the attached lander; when the lander is full, it detaches and flies up to dock with the refinery, which converts the karbonite into rocket fuel and deposits it in the tanker. Repeat until tanker is full. (If desired, I can detach the full tanker and leave it in a parking orbit, then send up a second tanker and fill it up too, and so on.) Now the starship _Voyager_I_ doesn't even need to descend to low Kerbin orbit (and ascend afterwards, costing lots of ∆v) between missions; it can just ease into Minmus orbit, settle into a parking orbit a few km from the refinery, and wait while the tanker putts on over and transfers all the fuel it needs for free. (Meanwhile the crew can fly to Kerbin on a spaceplane, check in at home base to drop off science data and level up, and return to the _Voyager_ on the same spaceplane.) If needed, conventional rockets can deliver new cargo to the _Voyager_, and everything's ready for the next mission!

I've just recently started trying Kerbal Attachment System and Karbonite, and while most of my crafts are still stock, I can see why somebody accustomed to them would have difficulty going back to not using them. Me, I usually don't update to the new version for a week or so not because of mods but because I usually start a new career with each new version, and I might have unfinished business in my previous career.

I usually try to get contracts that are a reasonable match for what I'm planning to do anyway.

Sounds good to me. I like the contract system overall but it gets really tedious clicking "no, I don't want that contract; show me another" over and over and over again. It would also be nice if there were a "decline all currently displayed contracts and refresh the list" button.

Unless I'm specifically using the flag to mark a location for future reference, I just plant the flag to get experience, hit "cancel," and remove the flag. I'm no litterbug!

What I like to do in early career mode--or at least as soon as I've researched docking clamps--is build two space stations (one orbiting Mun, one orbiting Minmus), each with crew quarters, a lab, plenty of fuel, and a detachable lander or two. If I time it right this fulfills a couple of Build Space Station contracts, and once they're in place, completing any "science from" or "survey" or "plant flag" mission on Mun or Minmus is quick, essentially free, and fun. It's also a useful way to give the crew some experience while also accomplishing something productive.

I do not understand this "hold off on playing" thing of which you speak; KSP is so enthralling that (with a few occasional exceptions) it's the only computer game I've played since I bought it nearly a year ago. I've also finally started trying some mods in the last few weeks and I'm having great fund with Kerbal Attachment System and Karbonite!

I'm highly in favor of all measurements being given in standard SI units. Just because some real world engineers are foolish and use imperial units doesn't mean Kerbals can't be smart for once.

Once I was launching an uncrewed delivery ship up to an asteroid carrying a bunch of detachable klaw modules (my intention was to place many stabilizer wheels scattered evenly around the asteroid). I had reached a stable orbit or close enough to it, so I pressed the stage button to blow the decouplers, detach the launcher, and activate the main nuclear engines. Unfortunately something went wrong... I don't know if the decouplers were attached badly, or if the launcher was off-balance, or if the nuclear engines ignited the remaining fuel in the launcher, but one of the big orange fuel tanks began to explode. I freaked out and cut all power to the engines, but it was too late; the explosion triggered a chain reaction and the rest of the launcher quickly became a huge fiery blast. In a blind panic I almost instinctively push the throttle to MAX and at the same time hit the screenshot button, ending up with an intact ship and a perfect shot... ...of outrunning the fireball.

Seems to me like the "provide X acceleration to part Y" contract could most easily be fulfilled by building a centrifuge. Long horizontal girder with horizontal solid boosters on either end pointed in opposite directions, and just enough vertical thrust to get it a few hundred meters up... then activate the solid boosters and watch your navball go crazy. - - - Updated - - - One neat thing I can see about contracts that require a certain temperature or a certain acceleration: it would make thermometers and accelerometers a lot more important!

I just recently installed the Karbonite mod and I've been having a lot of fun designing and implementing a Minmus mining outpost (surface base for extraction, orbital refinery for converting to fuel, lander for shuttling karbonite from one to the other). I'm looking forward to seeing how it is implemented in stock.

1) From the launchpad on Kerbin, I use D (if I felt a need to roll first, I'd just rotate it before putting it on the launchpad, but really roll doesn't matter for a radially symmetric craft anyway); when launching from anywhere else, I use whatever's needed based on the orientation I happened to land in. 2) Somewhere in-between: I burn retrograde until my trajectory meets the planet surface a little to the east of my destination (to account for the planet's rotation), coast in, and make adjustments as needed when I get close--an extra boost straight up if I'm not going to make it; a retrograde boost to kill horizontal velocity if it looks like I'm going to overshoot. 3) WASD to rotate; IJKLHN to translate. Why do we even have docking mode??