KerikBalm

West air, F=MA is not the equation to use. V != A What you inadvertently calculated (although with the wrong labels), is momentum, which is Mass* Velocity.

I made a mobile "dunce box" rover, all my astronauts with a stupidity level above a certain threshhold get placed in it, it sits in front of the astronaut complex to shame them. This is mainly for the unwanted recruit from rescues in orbit.

Meh, I find it easy to get enough science, particularly with contracts now.... an orbiting lab+ fuel depot + 1 reusable lander = 1 mission to minmus, 1 mission to mun = unlocked tech tree. For me, its just a matter of getting the grav detector so I don't need to land at the same places over again

They are not reasonably accurate by your criteria. Elevation = 0 on Duna has an atmospheric pressure of 20% that of Kerbin -> of course, the lowest point on Duna is still 124 meters.. but close enough. The highest atmospheric pressure I've recorded while exploring was about 17.5 % that of Kerbin. Most of my early landings were in 5% to 10% of Kerbin's atmosphere. Most of Duna's surface is pretty high, and thus in thin atmosphere. Its still very high compared to say... the pressure at the top of Olympus Mons. You can, of course, land on Kerbin without parachutes as well. Also note that a parachute that brings you down at 10 m/s at Earth's atmospheric *density* (its really density, not pressure, that is important) will bring you down at 100m/s in an atmosphere that is 1% of that density. So basically, IRL, parachutes still save all but the last 90 m/s of dV needed for a safe landing Also note that IRL, you would be coming in to mars at a lot faster than the 900-1,100 m/s for duna. http://en.wikipedia.org/wiki/Mars_Pathfinder#Entry.2C_descent_and_landing Another difference in on duna, the thin atmosphere has a low scale height, whereas mars, the scale height is quite high. Ie, it may be nearly a vacuum, but at least you get to travel through it longer.

Well, I'm having the same problem... I keep hauling uncrewed 100+ ton ships to orbit, and then having them sit there. Then I haul up another one... dock it with the first, and it... sits there. I was starting to amss an armada of ships in LKO, all waiting for transfer windows... (easy funds + SSTO launcher capable of hauling 100 tons = all my missions intend to leave orbiting labs and fuel depots above the target worlds - well, not so much Eve, not much point in an orbiting fuel depot if I can't also make a reusable lander, and there's no SSTO from eve, so....) Then I started sending out asteroid redirect missions, so far just two. Sure, if I wanted to simply rendevous, then again, I'd be waiting for windows, but I want to add new moons to kerbin, and that's a lot easier if I get to them early and nudge their PE into the upper atmosphere. I also launched some speedy ion probes to Eve, Duna, and Moho, completely ignoring transfer windows. I'm contemplating speeding up their trajectories even more, so that I can have science data from the target before I ferry a crew up to one of the waiting interplanetary ships.

This was my old all stock heavy cargo SSTO: Carrying a payload, of course (a ship+ lander intended for Laythe) But now the LFBs have been nerfed a bit and it wouldn't perform as well. This was an earlier, all stock (except the intakes were modded to produce intake atmosphere for electric atmospheric propulsion, which was not used on the craft, those intake modules were just shut) I haven't uploaded a picture of my current heavy lifter, but its for use with NEAR/FAR, and it uses the SpacePlane+ pack, which will become stock (and IMO, NEAR should become stock too)

As to what has been said - the 48-7s shines when you can get a low dry mass. When you have jets, wings, lots of fuel tanks, etc, the added mass of a 48-7s vs a LV-909 is often not greater than the difference between 350 and 390 IPS (as a %), so for any given dv, you use less fuel (there is a difference between mass optimal and fuel optimal, and with SSTOs, I worry about fuel optimal and not mass optimal). With stock aero, you can intake spame and get to >40km and >2000 m/s, requiring very little rocket thrust (in some cases, none, or ions alone can do it). With FAR/NEAR, I can't seem to get much above 1600 m/s surface velocity.

space mission, managing a station, sure. Don't give it control of the nukes, or the factories needed to build more of itself

Gravity: * The orbital mechanics with the debris field don't work * The MMU maneuvering by George clooney, especially in the beginning * That's not how you do an orbital rendevous * The chinese station was de-orbiting why? "Last days on mars" *craft climbs vertically, engines cut, craft's climb rate slows/ the craft decelerates, reaches apoapsis and.... "I'm in a stable orbit" This sort of vertical climb thing is portrayed over and over in movies

Its not about the magnitude of the difference, as I realize doing a burn at minmus orbit, or beyond minmus orbit, will not have massive differences. Its more about the theory, which is why I haven't given specific numbers, its not because an orbit is such a secret. Here are the orbital parameters for the numbers I arrived at, if that will make you happier: ORBIT { SMA = 11396924520.3127 ECC = 0.2170260877019 INC = 1.50113290597947 LPE = 338.895144038711 LAN = 137.362053173262 MNA = 3.79013058444902 EPH = 3617460.69961997 REF = 0 } After having thought about it some more, what one really wants is to have the AN be as far out as possible, and the DN as close as possible (or vice versa) so that the velocity at the node that you'll do the plane change is as low as possible. Assuming the AN is farther than the DN, this means burning at the DN to raise the AN, or as close to the DN as is possible without reaching escape velocity... which if the AP is already near the edge of the SOI, is basically at the apoapsis. But this is for large plane changes, I guess it would be nice to know the "break even point" going to the edge of the SOI may be most efficient for a 90 degree plane change, but not a 1 degree plane change.

^ the above, I have an SSTO that hauls upwards of 130 tons to orbit (I seem to be more limited by space for the cargo to go than anything else). While I have been able to land it on the runway, it involves a lot of quicksaving and loading... I found it much easier to just land next to the runway, and then turn onto the runway once I've slowed down enough. Momentum is enough and I often don't even need to add any additional thrust to get there.

Nobody wanted to correct the OP who said: "Just post a way astronauts could pass time on the way to Europa or to get their minds off the fact they will die before the ship lands and their great grand children will land instead." It doesn't take *that long* to get to Europa, you could go there and back in 1 lifetime, well before you have any great grandchildren.

^ That.... For every 10,000 jobs replaced by robots, you might create 10 jobs for maintaining those robots. The same trend is already affected industrialized countries with design& engineering vs production - except instead of robots, its cheap low skill labor in predominately asian countries. Society would have to change to more of a socialist system, or we will find the masses are in need of "reduction" by the few humans controlling the machines. Then it would be like the lords and ladies of old, with the peasants slaughtered and replaced by robots.

Plane change at AN/DN nodes is cheaper when you have less vertical velocity. Slowing the horizontal component won't help. Your vertical component will be velocity * sin angle at the AN/DN Slowing your total velocity (as with wider orbits) will reduce the vertical component The vertical component is really all you need to change to match planes. If APe is 90, then all your prograde velocity is also your vertical velocity. But at say... 45 degrees, a 10m/s burn only reduces your vertical component by ~7 m/s, at 30 degrees, only 5 m/s. I don't understand why you'd want to reduce your horizontal component - seems like a waste of dV. Eliminate the vertical component, at apoapsis, drop the PE into the atmosphere... aerobrake a few passes, raise PE, done.

"burn retrograde to stop all your orbital speed, then burn slightly east to raise your periapsis to just the right altitude in atmosphere suitable for aerobraking." I don't think there is any need to "burn retrograde", I'm fine with having an AP 50% farther than minmus, I think just the normal/antinormal burn to match planes, and retro only as needed to prevent reaching escape velocity (shouldn't be needed at all, unless you are trying to increase APe), then once AP is reached, then drop the PE... Sure, that takes a lot longer, but we're talking minimum dV, not fastest

So I just set up a craft into an orbit with a high APe (I was aiming for 45) and apoapsis beyond Minmus orbit. Doing the plane change at the DN would cost 312 m/s, and then another 18 m/s to aerobrake Total: 330 m/s Circularizing at the Apoapsis would cost 169 m/s Doing the plane change and dropping the PE down to aerobraking cost 220 m/s Total for circularizing first and then plane change: 389. I conclude that I should just pick the AN/DN furtherst from Kerbin, and do the plane change there, unless my APe is really high... as in more than 45 degrees

It does have to do with the APe. If APe was 0, then the plane change should be done at apoapsis for minimum dV. In the case of APe=0 or 180 either the ascending, or the descending node will be at apoapsis. But with APe != 0, its more complicated. I guess I should still try to reduce the velocityof one/both of those nodes, and do the burn there. No, it is defined as the angle between the AN and Pe. The longitude of the AN is not relevant. Not really a complete coordiante system, just a reference plane, and its not an arbitrary plane, or at least I would argue the equatorial plane is not arbitrary or irrelevant, given the reduced launch costs and most other bodies orbit in that plane or nearly so. Well, as I see it, the point is to make the velocity at the AN/DN as low as possible, so its as cheap as possible to change. The relevance of a non-zero/180 APe is that you do the circularization at apoapsis. This step would be skipped for an APe of zero. Thus the relevance of APe != 0 is the relevance of the circularization burn. Btw, you earlier made mention of flintknapping - I used to do a little of that myself. May I assume you use "old school" tools such and deer antler? Do you prefer obsidian or flint? I always had and easier time coming by obsidian where I'm from.

Kashua's pretty much the only one in this thread that seems to get the point... LAN I pretty much don't care about, but APe is absolutely relevant if you want to go to an equatorial orbit... surely Geschosskopf (projectile-head? shot-head?) you pay attention to the equatorial plane, no? Its not that "hard", what I'm talking about is an optimization problem. If I don't care about optimization, then its just burn normal/anti-normal at the AN/DN nodes, circularize at perapsis/apoapsis. You don't even hear much about the most efficient way to change inclination on these forums. Guides to getting to minmus will tell you to get in orbit, match planes, and then go... fine, but not efficient. Better guides will tell you to launch into the correct inclination, or time your burn so you meet Minmus at the AN/DN. Not much discussed (although it is mentioned on this thread), is how to most efficiently change planes by sending your apoapsis way out and doing it there - implicit that this is done at an AN/DN node. Now I'm faced with a scenario where my Apopasis is already way out there, but its not at the AN/DN node. This scenario would never reasonably happen in the first place for a ship under player control, and cellestial bodies can't have their orbits altered, so its been quite irrelevant until asteroids are introduced. Marvin: "you need at absolute most about 500m/s, and that assumes that your rock needs to be completely u-turned around in addition to getting its inclination fixed. Orbital speed out near the edge of Kerbin SOI is *very* low." That assumes you can fix the inclination at the edge of the SOI... in its current orbit, I can't. If your Apopasis is directly above a pole of Kerbin at the edge of the SOI, you can't put yourself in an equatorial orbit with a plane change at apoapsis. If the apoapsis is on the equatorial plane, then its easy to turn a polar orbit into an equatorial orbit. Its not that bad in my case, but I'm just trying to figure out the principles in general for dealing with these orbital changes in the most efficient manner. Kashua, I need to rotate the plane of my orbit about 2 axis, if I burn at Ap to raise my Pe for a more efficient change along one axis at An/Dn, that means the other axis I need to rotate will take more dV because I'm now moving faster at Ap. My plan is to rotate the plane along the first axis at Ap, this is the plane that is most out of what (since APe is not all that high), then raise my Pe from there, to fix the 2nd axis at AN/DN... although I'm still hoping to be able to use Mun to save a lot of fuel. I was also considering lowering the PE with aerobraking, so that I can raise the Ap again, but also move it closer to the equatorial plane - for example, if my PE is below the 15 degrees below equatorial plane, wait until I pass PE and the equatorial plane, and then burn prograde 15 degrees above the equatorial plane. I worry about the cost of raising my PE for changes at the AN/DN, if I then want to lower my PE again. So far I havent rendezvoused with it yet, as I said, its my career save, and I've got other things happening before that burn is scheduled (I need to get Kerbal Alarm clock). I've got a manned ship nearing the edge of kerbin's SOI that I will need to send back to Kerbin, I've got a transfer window from Mun to Minmus for my science lab+fuel depot, a manned craft returning from minmus(maybe I should burn some more to speed up its return, I don't have DRE installed, so ) - and orbital assembly of some other ships for interplanetary missions (if I don't do the rendevous now, it will be many many orbits before they are close again). Of course, now that its easy to have multiple saves, maybe I should just time warp ahead and skip all that stuff. Or maybe I should just make a sandbox save, and put a craft into an orbit with an APe of 45, and a PE right on the edge of the SOI, and then try different approaches to getting back to equatorial orbit, and see which one has the most fuel remaining.

I was speaking generically, like if in the process of changing my APe, I lower my eccentricity, then the plane change will be more expensive. I think I'll first do a normal plane change at apoapsis, and then tweak it to see if its worth raising my perapsis for the 2nd plane change at the AN/DN, knowing that I'll have to bring it down again to aerobrake. This is only a C-class, so it should be about 100 tons, I should have no problem getting 100 tons of fuel up to orbit with LV-Ns, which tells me that I'll have a wet:dry ratio of about 2:1, so the rocket equation tells me I should be able to get about 5,000 m/s of dV with the roid... so I'll be able to do it on my own, I'm more of asking for the techniques/methodology, so that when I go after E-class roids, I don't run out of fuel, or need a ship so big that my computer crashes. (with 100 tons of fuel, and a 1000 ton roid, I'll get a dV of less than 800 m/s) Geshosskopf - until the introduction of asteroids, there was little reason to use the terms, as except Eeloo, most bodies were in pretty circular orbits. And most ships travel in equatorial or near equatorial orbits, were APe is nearly zero. These roids though... get captured into some weird orbits, and as a result, these terms are now useful.

There are 7 types of propellant in the stock game, obeying 3 different sets of rules: * Solid fuel Cannot be transfered/does not "flow". As such there are no separate "tanks" and "engines", just combined units. A unit can only use fuel it stores itself. These rockets cannot be shut down, they cannot be throttled, and they cannot be refueled. these are all the solid fuel boosters, which includes the launch escape system and the sepratrons. The game files say: flowMode = NO_FLOW transfer = NONE * Unlimited flow: Monopropellant, Xenon Gas, intake Air (also electricity, but that is massless) No fuel lines are needed, if its stored anywhere on the craft, it can be used. Recently there was a change so that monoprop and xenon drains from sources according to their staging priority, instead of evenly from all sources (although I'm not sure intake air obeys this rule) Monoprop: RCS blocks and ports, the O-10 engine Xenon gas: the ion engine, also consumes electricity Intake air: the jet engines, these also use Liquid fuel, which obeys a different flow rule. Intake air can be stored if the intakes are shut (you can shut intakes, which will all be partially full, transfer everything to 1 intake, open all except that 1, transfer everything again, and so on, even then, you won't have much stored for use in orbit) The game files say: flowMode = STAGE_PRIORITY_FLOW or ALL_VESSEL transfer = PUMP * Liquid fuels: Liquid fuel (duh) and "oxidizer" Most of the engines use Liquid fuel and oxidizer in a 0.9:1.1 ratio The airbreathing engines use liquid fuel and intake air in a 1:15 ratio The LV-N, even though it should not use oxidizer for realism purposes, uses oxidizer in the same ratio for gameplay purposes so that they don't have to add new fuel tank types These flow freely within a stack, assuming you don't have a part in there that interrupts the flow, like decouplers These fuels can be manually transfered. The "top" of a stack drains first. Fuel lines can be set up to automatically transfer/drain fuel to/from the parts of your choosing. The game files say: flowMode = STACK_PRIORITY_SEARCH transfer = PUMP Anyway, your fuel lines don't work because you're trying to move liquid fuel to an engine that uses solid fuel.

Correct. But I'm already aware of the most efficient way to change inclination to an equatoraial orbit once at zero APe. Of course, if getting to zero APe takes away all my eccentricity... well, then that makes the plane change harder, and its an optimization problem as you say.

I really have no idea what sort of reasoning leads you to the statement that APe and LAN are meaningless already. Btw, its not a polar orbit, you can't see well from that angle, because the orbit is "coming out of the screen". That angle really shows the deviation from the equatorial plane, as I said, its really only about 15 degrees. this is another view Assuming it was a polar orbit, with the Apoapsis above th north pole, doing a plane change there will always still result in a polar orbit... you can change if it intersects the equatorial plane between kerbin and the sun/with kerbin between it and the sun, to crossing in front/ behind kerbin's orbit (ie kerbin prograde/redtograde directions)... like a spinning coin standing on its edge, the plane of the coin is rotating, but the coin is still standing up and not laying flat on the table. Oberth describes the ost efficient way to change your ships energy. Going from one plane do another plane does not increase your orbital energy. This is why plane changes are most efficient at apoapsis -> oberth doesn't apply. Suppose you are in a perfectly polar orbit, and want to go perfectly equatorial. Suppose at the ascending/decending node, you're going 2,300 m/s North/south, and 0 m/s East/west, you need to kill 2,300 m/s of north/south velocity, and add 2,300 m/s of east/west velocity. Pythagoras tells us a burn of 3252 m/s is required to do that. In contrast, a 900 m/s burn puts us out to the edge of the SOI, where the orbital velocity is about 250 m/s, we then do the plane change for sqrt(250^2+250^2)... 353 m/s. If it were a world where we can't aerorake our apoapsis back down, then another 900 m/s would be needed, for a total of 2153.. over 1000 m/s less (but since we can aerobrake, we save nearly 2,000 m/s doing a plane change like this) In this scenario, we chose our APe by doing the burn to increase our apoapsis. but that applies to highly inclined orbits... for an inclination of say... 5 degrees, you don't want to spend 900 m/s to extend your apoapsis. But if I were in an eccentric orbit with an APe of 90, then doing plane changes there would be like spinning a quarter standing on edge when I want to to lie flat. I'm basically wondering what the most efficient way is to set APe to 0

and in that case, you want to use the lander cans, since they are lighter with more monoprop. and you also want to use the single occupant pods/cans, because 3x single pods weigh less than 1x 3 man pod

Sorry, too much "I believe" in there. Space is empty... it is so so so empty. Hydrogen atoms are flying around, but... they rarely even collide. You're not going to get an acellular living system from a few hydogen atoms occasionally bumping into each other. When you start getting to planets and moons, then you have some chances for interesting things to happen, especially on Mars, CeresEnceladus, Titan, etc. We've been to the moon, what sort of self replicating system do you "believe" is there, and what evidence do you have for it? If you can't find one on the moon, how do you expect to find one in a vacuum with a few hydrogen atoms per m3?

Once it is circular, it is meaningless, but its not circular yet, and its not meaningless yet. I can't do the required plane change at apoapsis... because apoapsis is well above the equatorial plane Its only a C-class though, so I think I'll do as Kashua said and not bother with gravity assists... and I'll try to capture that E-class I'm looking at cleaner than this self captured C-class has ended up.