AeroGav

TL;DR The short version is that existing lithium ion batteries can last practically forever if you undercharge them. Charge and Discharge cycles are irrelevant - though since life is normally quoted in terms of "charge discharge cycles" manufacturers do their testing by blitzing the cell with a really fast charge and discharge rate that runs it down (and charges it back up ) in just 20 minutes. This enables them to fit as many cycles in as possible before the battery degrades. What actually causes degradation is unwanted chemical reactions that break down the electrolyte and turn it into solid gunk that deposits on the surface of the anode/cathode. Eventually this plugs the pores and lithium ions can't pass through (fast enough to meet the current needs of your device). There are three things influence this reaction rate 1. state of charge. the reactions pick up exponentially after 70% 2. temperature - lower the better. hot and fully charged is a particularly bad combo 3. additives put in the electrolyte to slow this process In the above video he talks about some early lithium ion batteries that had been left at 20% state of charge since the 1990s. They hooked them up and ran a capacity test - they performed like new. So are manufacturers going to give you a slightly larger battery and charge it to only 70%, or take a 30% on the claimed battery life for your next smartphone so it'll last a decade or more? Or are they going to charge it to 100% , and make a huge profit on the replacement battery market. Gee let me guess...

The only trouble with high wing positioning, is that moving the mass of the wing upwards also raises the centre of gravity of the airplane. Which means that engines may now be below the centre of gravity, causing a pitch up tendency when power is applied. This is especially noticeable if it's a wing that contains fuel, since it has a greater mass, and especially noticeable when operating in close cycle mode - engine thrust remains high as the air gets thinner, but the control surfaces have less and less ability to fight the pitch up tendency. Ah well, this is where Jebediah earns his pay.

Hi all. I like to big aircraft with a lot of lift, so for me the stock parts are only suitable for mk 1 fuselage vehicles. For mk 2, I used to stitch together a godawful patchwork quilt of 8 big-S delta wing pieces and use kerbal joint reinforcement and a fuel balancer to hold it all together. Really though, it would be better to just have one sufficiently large wing. I used to be a fan of b9 aerospace procedural wings but seems it's not been updated for 1.1.0. Are there any other parts packs/procedural wings that might fit the bill?

Bit of an obsession of mine, but can I just clarify everyone here understands the difference between Pitch angle and AoA , or folks can talk at cross purposes for hours ! Pitch Angle is the angle of the nose relative to the horizon. AoA (Angle of attack) is the difference between the direction of travel (prograde icon) and the pitch angle - ie where the nose is pointed. Eg. You could be running a pitch angle of 25 degrees (nose 25 degrees above the horizon). If the prograde marker shows the trajectory (in surface mode) is of a 20 degree climb, the AoA is 25 - 20 = 5 degrees. That's a good situation. However, with the same pitch angle, if your prograde trajectory was only 10 degrees above the horizon, then you would have an AoA of 15 degrees. That's not ideal in most spaceplanes, you're going to have a lot of drag. If the prograde was descending at 10 degrees, then your AoA would be even worse 25 - -10 = +35 AoA. That's over 30 degrees, meaning you just stalled ! ------------------------------------------------------------------------------------------------------------------ I prefer to aim for a specific AoA than a specific nose angle, there's two ways you can do this 1. Is to use pitch trim (Alt + S trim nose up, Alt + W trim nose down) with SAS off, and let the airplane "find" it's own nose angle. The airplane will tend to settle at whatever AoA you trimmed for, though the resultant nose angle will depend on how much power the engines are producing. I generally use kerbal engineer to show critical thermal % and vertical speed, and watch the trends. If I'm getting uncomfortable about the temperature and rate of climb isn't increasing, i add three or four notches of nose up trim. Generally it's good to make small adjustments early. This does take a bit of familiarity with the airplane and also the way rapier output increases with speed can mess with the airplane's ability to find it's natural nose angle. 2. Angle the wings with 5 degrees AoA in the SPH relative to the fuselage. Set SAS to Prograde. The SAS will hold the body of the airplane to less than 1.5degrees AoA throughout the flight, but the AoA of the wings will always be 5 degrees more than the aircraft as a whole, and you should always have enough lift. Why is AoA so important? Because it determines lift and drag. Lift goes up with increasing AoA, as does drag. The best lift:drag ratios occur at 2-5 degrees AoA. Below 2 degrees you are probably not climbing steeply enough and are going too fast in air that is too thick. Above 5 degrees AoA drag starts increasing much faster than lift, and causes losses in your ascent.

Yeah I'd heard of that - in all my spaceplanes, the inboard wing sections have 0 dihedral, but the outboard has 30 degrees. The test craft i pictured also had outboard wing dihedral (gull wing style), but that V shaped section under the main fuselage was below the CG, making it a low wing aircraft which would counteract the effect. As regards the spaceplane, 2 pairs of struts seems best. I am tieing together the two wing segments furthest apart on the craft file tree structure, but the really key strut is the one that ties the two tailcones to the cockpit. The problem was that at high speed the lift forces were torquing these upwards, and the forward 2 wing segments are mounted to this part - the two front wing segments therefore get increased AoA and more lift than the rears, and act as giant canards. I've noticed that the reluctance to respond to roll input may be down to the trailing edge wing segments torquing up when using ailerons to try pick the wing up. This results in the wing as a whole angling downwards generating less lift, counteracting the effect of the aileron. Or it's just an adverse yaw resulting from aileron drag, not sure which yet.

I'll keep on iterating the design till the coffee runs out. Mark II has the following changes from the one you flew two standard canards replaced by three advanced canards, clipped to make a blended wing body effect in the nose two big-s strakes removed, replaced by the small strakes to seal up the gaps. reduces lift at the front end a bit i've been repeatedly urged to add incidence to my wings. After opening the aerodynamic debug i was shocked to see how much drag the body was generating, so i added a few degrees by hand. Hard to do on a complex design like this. Body drag is indeed lower, but not sure overall picture is better. I've always stayed away from this for fear of making stall/departure characteristics worse on a canard design. Still only getting Lift drag ratio of 10 (subsonic) to 3 (high speed). But I must admit, it's nice being able to fly much of the mission with SAS set to Prograde and forget about it. Next thing to try is struts , as you say. BTW I am using GPOSpeedFuelPump to keep the engine pre-coolers, which serve as feeder tanks for the NERV, topped off. It was the first fuel balancer to become available for 1.1.0 and I like the way you can set it up in the SPH/VAB and the settings are kept. TacFuelBalancer had to be switched on every time you loaded a quicksave. First orbit in 1.1.0

Thanks for checking. I'm coming to the same idea. It starts to wander off heading by the time it's flown the length of the KSP runway, couple of degrees out, then as the nose rises to 30 or 40 degrees a wing begins to drop. Yes it needs a fuel balancer mod to keep the feeder tanks for the NERV topped off. I've not used fuel lines or struts because I heard they had VERY high drag levels - couple times more than the cockpit. I'll probably have to take down that version of the ship on KerbalX - it's too unstable in high dynamic pressure situations. Got to about mach 2 @ 16km or so then when I brought the nose up 5 degrees off the prograde it suddenly snaps in to an 18g pull up and a dramatic reconfiguration of the airframe So, it turns out you got that thing closer to space than i ever did. I've tried shifting the CoL further aft and making the canards smaller, trouble is the max AoA you can now achieve is 6deg, costs us most of our STOL capability....

http://kerbalx.com/AeroGav/Tundra-Goose This STOL spaceplane I was working on also seems to have negative roll stability, despite dihedral on outboard wing segments at 30 degree angle. Wonder if you can confirm that's actually the case or it's just my flying that's off.

I give up ! All I want to do is make an airplane that has a tendency to return to wings - level if disturbed to a few degrees of bank angle, one that does not constantly need to have uncommanded roll angles taken out by hand, and can stay on a steady 90 degrees due east heading without continual course corrections. I build a simple test plane big tail fin, yaw stability plenty of dihedral Despite the above, roll angle gets bigger the longer i leave it uncorrected, plane would spiral dive into the ground if i let it. However, the smallest elevons are having trouble putting any bank on that i do ask for, it's almost impossible to turn this plane at all without the rudder - so maybe it is doing something after all?

Well, so far so good. It's flapping less and no Krakens, but I did destroy the VAB a couple times. STOL performance seems quite decent.

I've heard that 1.1 is very sensitive to problems caused by clipping. These days, I try hard to not intentionally clip any parts. However my space plane wing is comprised of 4 big S wing panels. Previously, I'd attach the first wing to the fuselage, the second wing to the first wing, and the third and fourth wing sections would attach to the second. However, there is not (yet) a Kerbal joint reinforcement nor a Tweakscale for 1.1 release, and this configuration flaps quite a lot in flight without Kerbal joint reinforcement. Hardly surprising, since my tree structure has one wing panel bearing the flight loads of all the others, and the outer wing panels are 4 nodes away from the root part. So, I thought I'd rework my design to try and get it as stock and mod-free as possible. I removed the front pre-cooler pair, replaced with reversed tail cones (flight testing revealed one pair of pre coolers is plenty to run a Rapier and Two Panthers). Then experimented with attaching more of my wings direct to the fuselage, to reduce the flapping. However you can't attach wings radially to engines and there is now only one pre-cooler per side. So one wing attaches to the pre-cooler and one attaches to the cone at the front of these nacelles. The problem is, the cone is at an angle as will be the wings, and it all looks a bit of a mess. Will I be storing up problems for myself if I allow the wings to clip inside each other in places to seal up the gaps between non-aligned wing panels, how far do things have to clip inside each other to be a problem? Or should i just put up with the flapping as "cosmetic". At least it looks like it's trying to help you get to orbit.

Actually I wish i'd used a different name for this game mode suggestion in the thread title. "Finance mode" etc. I don't want an annual budget, which you could just time warp through to next payday and render it meaningless. You should earn the cash from achievements and contracts instead. In the same way that Career and Science modes don't just grant you free science every calendar year, you have to do things to earn it. You start off with a small amount of money, make a minor achievement/fulfill an unambitious contract, use the cash generated for a slightly more ambitious next mission and so on to Eeloo/Moho. Obviously if you find yourself stuck in low Kerbin orbit because things have gone wrong and are unable to make the next leap with cash available, you should still be able to grind out with tourist / 1 star contracts to the next step, rather than being forced to start over. I did try a custom start with minimum money and vast quantity of science, but i was unable to unlock the tech tree because i didn't have the cash to upgrade the R&D building to unlock nodes 5+. I had a load of science points i couldn't spend. I guess I'll try again and give myself just enough cash to fully upgrade the R&D building to max level as well, but start the game with every other building a tin shack. Should be fun ...

I've been puzzled by this omission and wonder if there's a mod that adds it. We have Sandbox mode, where you have full access to everything. You have career mode, where both science and funds are limited. And there is science mode, where you start off with fully upgraded facilities and money is no object. Why isn't there a fourth option, where the whole tech tree is unlocked, but you start off with a shoestring budget, the most basic facilities, and no rep, and have to build economical rockets or increase re-use, to gradually upgrade facilities, build out your space infrastructure and start putting Kerbals further and further afield. Would reward smart vehicle design and use of SSTOs or just partially re-usable vehicles, rather than putting you in the position of say NASA at the start of the space race, with no tech but huge resources, it would be like a present day or near future scenario where a smaller nation that formerly had no space program decides to start exploration?

The thing is nearly all rocket engines have turbines as well - the turbopumps that put the fuel in the combustion chamber - that could in principle have an alternator attached. In practice i'm not sure many real life rocket engines actually do that. The space shuttle had fuel cells for electrical power running off their own, super-insulated tanks in the bottom of the cargo bay. Hydraulic power came from a hydraulic pump powered by hydrazine. Liquid fuel engines basically have 3 ways to get the fuel/oxidiser in - 1. combustor / pre-burner providing hot exhaust to drive a power turbine that spins the turbopumps. All lower stage, high thrust engines use this method, it's the only way to get fuel in fast enough, but it's a lot of extra complexity. 2. expander cycle engine - liquid hydrogen is first pumped around the nozzle, cooling it, and the expansion of this now boiling LH2 spins the power turbine that drives the turbopump. Simpler, but fuel delivery rates are lower as are power. Common in upper stage engines. Terrier and NERV appear to use this method 3. pressure fed engines. Fuel forced into combustion chamber by pressurization of the tank alone. Low performance but no moving parts. For when it absolutely positively has to work. eg. Lunar module engine. 1 & 2 have turbines you could run an alternator off. Is it not just a balance issue? Hence the Aerospike & NERV can't gimbal, RAPIER got no alternator etc?

Well, this low tech panther/terrier airplane reaches orbit with about 200 LF/O remaining. When you're dragging the mass of the wings, control surfaces, now-empty tanks etc. that's only 400 delta V , not enough for anything useful. By detaching the section containing an FT200 tank, the terrier engine, and the cockpit, pumping all your fuel into it first, you are drastically reducing the amount of weight that fuel must lift. You can see we have 1700dV after separating. This is enough to orbit Minmus. You can then fly back, dock with the plane again, re-enter and land normally - everything re-used except the jet engine stage. I did try visiting biomes by spacewalking but the prograde/retrograde markers went wierd on me, would not have been able to get back i think.

After the previous monstrosity, I resolved to put together a nice simple design that would be easy to replicate, would not abuse clipping, not require the presence of mods, be easy to fly and not succumb to over-engineering. Well, the over-engineering part was a struggle I tell you. The part count crept upwards like the JSF budget. So, I present, the Frost Wing https://onedrive.live.com/redir?resid=7003A8806D8A6B2C!729&authkey=!APewUzZ3WMhJHrM&ithint=file%2ccraft The initial idea was a simple 1 nuke/1 rapier mk 1 plane that stages off it's rapier to solve engine placement / thrust axis issues simply. But it had enough delta V that simply orbiting Kerbin felt like a waste. Also, what to put between the cockpit and the NERV? Mounting it directly overheats the cockpit. Answer - ISRU ! Let's go to Duna and Back ! Only now it climbs sluggishly in the lower atmosphere and wastes half its fuel before going supersonic. Pod mounted Panthers to the rescue. Worse, I'd decided to revisit something that doesn't really work properly in KSP - landing flaps. That took so much tuning. Staging Info First Space bar starts the Panthers Second Space bar starts the Rapier Third Space bar drops the Panthers Fourth drops the Rapier and starts the NERV Action Groups RCS - not only starts the RCS, it enables capsule torque and deploys the landing flaps. This is an experimental feature that may slightly reduce landing speeds. Should only be used on Duna below 100 m/s , or the aerodynamic forces will overwhelm the RCS which is needed to overcome the pitch down effect of landing flaps. Also should only deployed @ 100m above ground level or the RCS could run out. Abort - toggles the panthers between afterburner and dry thrust. Recommend flying to at least 10000m before attempting to go supersonic. Use afterburner when levelling off to accelerate through sound barrier, cancel burner above 400 m/s. Above 15km , turn A/B back on again, unless already over 750 m/s in which case press space bar to drop the pod mounted engines. Above mach 2.8 drop these engines. Bring an engineer for better mining. There is a probe core in service bay so you won't need a pilot.

Yeah aesthetically, it's MK2 > MK1 > MK 3. Really don't like the look of mark 3, and the lack of inline cockpit, and none of the stock wings are as large as i'd like for a Mk3 aircraft (except the Fat-S airliner wing, which looks out of place on a spacecraft and hasn't got a great temperature tolerance). MK2 of course will always have more drag than mk1 because of the increased frontal area. Nobody picks mark 2 parts for the fuselage lift, the reason my aircraft has mk2 fuselage parts is because a mk1 cargo bay wouldn't hold all that much. MK3 are worse again, and they have very poor engine mount options. The mk2 bicoupler is decent enough, but the mark 3 engine mounting plate - in the style of the space shuttle - creates enormous amounts of drag. Instead people end up clustering a silly amount of mark 1 sized nacelles radially. You can see in my screenshots there is neither lift nor drag appearing on the aero forces display at the AoA and dynamic pressure regimes I encounter when flying to orbit.

As you unlock more tech the amount of fuel that can be brought to orbit per flight goes up. As for what tech to spend the points on, well it's mainly about having the best possible airbreathing engine. The Terrier is a great closed cycle engine and appears very early in the tech three. All the others are heavier and have worse Vacuum ISP, the only improvements to be had are in Sea level ISP and Thrust which aren't important in a spaceplane. The nuke is a step up but not vastly better if you're just shuttling to low kerbin orbit, it really comes into its own if you're flying beyond. All wings have basically the same performance, regardless of shape. The Fat S airliner wing and the Big S space shuttle wing/wing strake are an improvement, because they have the same mass/lift ratio of the others, but also have considerable liquid fuel capacity. However they appear late in the tech tree. Air intakes - I've not noticed any improvement upgrading air intakes on my designs after researching new ones, it must be a very small difference. Landing gear - absurd though it sounds, i've built plenty with fixed landing gear. The drag penalty does not seem all that large, if you don't try to go fast low down any rate. The main problem is they will probably burn off on re-entry. So you may as well use decouplers and jettison after takeoff. Just land in the water when the mission is over, easy. I have a Panther/Terrier aircraft, it jettisons the Panther on the way up (cost about 2000 kredits per flight in non-re-used components) and makes orbit with about an FT200 tank full of fuel left over. I designed this so the cockpit and engine section could undock in orbit without dragging the rest of the airframe with it. Without the docking ports and sponsons, or maybe with just a probe body and no cockpit, you could perhaps do a little better, but really it's a lot of work flying to orbit for 20 minutes , then rendezvous and docking (an hour?) for 200 LFO. I hate docking with a passion btw. You'll do much better with the Whiplash engine. 600 per flight? And my type 2, sandbox spaceplane with access to all techs, Rapiers, Nukes, etc. carries 1300 to orbit at a time. I still hate docking though. In my career games, i put an ISRU spaceplane on the flats as soon as i am able. Flying to minmus , landing on the flats and taxying up to the IRSU rig is a lot less fiddly than rendez/vous docking in my experience, and rewards you with a full load of fuel every time. BTW did I say I hate docking?

I'd be happy for someone to try out my Penta Star design. I'm linking the bare bones version so it doesn't have any kind of docking port currently, but it has two large empty mark 2 cargo bays so you could probably just put an inline clamp-o-tron in there or something. BTW It doesn't need to refuel at all to fly loads to minmus and back, if they're bulky but fairly light. Refuelling is needed for missions to Duna and Laythe. Download the CRAFT file from the Microsoft Onedrive link here.. https://onedrive.live.com/redir?resid=7003A8806D8A6B2C!713&authkey=!AKArjxC_7Z_h9kk&ithint=file%2ccraft I have not tested the design without Kerbal Joint Reinforcement, I don't think it would end well, due to having 4 sets of wings attached to each other. Also, you are going to want TacFuelBalancer. At the start of each flight, click on the Liquid Fuel tab and press the "Balance All" button. The jet engines drain evenly from every tank but the NERVs are classed as rockets and won't use any of the fuel in the wings (ie 90% of it) unless you run a mess of ducts everywhere. This mod takes care of that problem, makes sure the feeder tanks never run dry. That forum post contains advice on how I think it should be flown. Besta luck...

Were you getting sufficient drag to show up on the F12 aero forces display as per my screenshots? As you can see I'm not experiencing enough to show up as red lines on the aero forces display, except when accelerating through the transonic region 10-15km. Even then the red lines are coming off the wings and engine nozzles not the fuselage body. That said, my airplane isn't one that would benefit so much from this tweak , due to having the type 2 lifting fuselage, and also having far more wing than fuselage generally. It also flys at very small AoA, due to the large wing. I did try using incidence angle but didn't like it. For a start, the SPH provides no way to rotate a precise number of degrees, you have to use the rotate tool in fine mode and do it by eye , which drives me crazy. What if you have multiple wing sections attached to the fuselage, how to you get them all at the same angle ? Second, it causes the wings to stall out before the canards and fuselage lift, which creates some nasty departure characteristics. On a tail plane rather than canard design, i guess having the wings stall first is actually a good thing, so this is preferable, but definitely not on a canard. Third, it's hard to optimise over the whole range of AoA used in the flight. I start at about 1.5 AoA during my speedrun - say mach 4.5 and 24km, and increase to an AoA of 5 by mach 6 and 30km+. Using too much incidence would result in negative AoA on the fuselage at certain points. Again, this is a function of my design. Most Spaceplanes I see people make have tiny lift surfaces. I've seen someone build a type 2 with 6 engines and only a pair of Big S strakes for wings. It was pitched up at 25-30 AoA above 20km so would benefit from your advice. I don't feel all my wings are dead weight because they are also holding 90% of the fuel. But in an LF/O setup that would not be the case, you might feel differently. Also, I designed that thing to be capable of landing on Duna. It touched down at just 32 m/s, which is safe and easy. A previous design I did had similar weight but only two pairs of wings and came in at 70m/s. Took twenty attempts to land without damaging it.

I'll rephrase this again - I PUT THE XENON IN THE KERBODYNE TANK IN ORDER TO CREATE A 30 TONNE BALLAST TO SIMULATE THE WEIGHT OF THE LANDER OF A PERSON WHO WAS HAVING TROUBLE PUTTING HIS 30 TONNE LANDER ON MINMUS. That user hadn't linked a craft file for his lander and was using mods, including a large nuclear reactor for electricity generation, which I did not have installed. Creating that Kerbo-Xenon tank was the quickest way for me to create a 30 tonne ballast that was about the same size as his lander, so that I could spend more time designing the launcher itself, rather than first trying reverse engineer his Minmus base from a picture. I'm sure it's still a rubbish rocket but it's the most powerful i've ever built by some margin. It was done more to challenge myself than help the OP, other more experienced rocketeers had already posted designs. I normally concentrate on Spaceplanes. Pretty sure that person was also in a Sandbox game, so cost was irrelevant. If I remove the Xenon payload, cost drops from 4 and a half million Kredits to 432,000. Delta V also goes up to 6700. Xenon is clearly a VERY expensive propellant. It's also much heavier than an LF/O tank the same size.

Above 10km they produce near vacuum thrust like any other vacuum engine. A mark 1 spaceplane with a large wing and no drag can accelerate to orbit on just the 60kn from an LV-N NERV, providing something else lifts it to 10km in the first place. Up scaled to 1.25m, the ION engines make 11kn each and can be stacked. So , it would be possible, if you can avoid the drag problem and get enough electricity going. Again that means modded parts though.

Someone wanted a rocket that could put a 30T lander on Minmus. I don't have his mods so i used ModularFuelTanks to swap the contents of the top Kerbodyne tank to 30 Tonnes of Xenon. That's probably why. All I need to do is add one Ox-stat and a Dawn thruster and i'd definitely win the Delta V race. TWR on the other hand...