Starman4308

Eh, even in stock KSP, fuel costs are still a relatively small fraction*. The use of FAR/NEAR alone is going to do far more to unbalance KSP's career mode than a drop in fuel prices. *The only major concern would probably be SSTO spacecraft, which go from "ludicrously efficient" to "plaid efficient". Unless, of course, you neglect the rearwards shift of CoM, and it lawndarts on reentry, in which case your recovery is approximately 0% of value. Might I suggest the formula for procedural fuel tank costs be (tank type modifier) * (1.5 * volume + 200)? I'm not sure if the config for RealFuels should be part of that mod or part of Procedural Parts, but for that, just swap out 1.5 * volume with 0.4 * volume. That should approximately get the costs of large fuel tanks right, while still adding a penalty for dinky tanks.

During ascent, you have control over your acceleration, and that ascent is usually not too fast because of issues which crop up when you ascend too quickly. During reentry, you're quite ballistic: if you've got FAR installed, you can control your reentry a little bit with a lifting reentry, but you're still mostly ballistic. In stock KSP, you're ascending at ~2 G to avoid exceeding terminal velocity (going faster makes you waste fuel fighting atmosphere). In the real world, or when playing with FAR/NEAR, you generally start your ascent at 1.2-1.6 Gs of acceleration because, were it any higher, you would risk aerodynamic failure. In either, during re-entry, you're on a ballistic course for lower atmosphere, and no matter what tricks you play to bleed off as much velocity as possible in the upper atmosphere, sooner or later you will slam into lower atmosphere with a lot of velocity left, where drag will hit very, very hard.

Whipped up a spreadsheet. Stock KSP values are on the left, values for my usual configuration (Real Fuels w/ stockalike config) on the right. The summary is that, in stock, for typical tanks, it costs 1.541 funds per unit liquid fuel + oxidizer capacity*. Fuselages are a little bit all over the place, but generally cheaper. The smallest 1.25m tanks, the Round-8, and the Oscar-B all cost more (sort of to be expected). For Real Fuels, similar patterns apply, with 0.41 funds per liter capacity. I also suspect somebody at Squad might've made a typo entering in the cost for the Kerbodyne S3-14400 (given the pattern, I suspect it was supposed to cost 28,800, not 22,800). EDIT: Made a goof: 1.541 funds/L is the figure with accounting for oxidizer volume. It's 4.44 funds/volume LF in stock.

Great capsule: it'll really fill a niche for me (Apollo-like missions, but with only two Kerbals, because the two-Kerbal landing pod is ridiculously overweight). A few comments: #1, it has no electrical charge storage, #2, it seems to have a rather disproportionate amount of RCS fuel, and #3, it would be nice if it came packaged with a decoupler/stack separator. It's also a little bit more prone to heat conduction than it really should be when there's still ablative heatshielding left, but it isn't insta-death.

There will be Windows x64 support when Windows x64 stops being an unstable piece of crap for so many players. Some get Windows x64 to work well: it seems to come down to unknown differences in hardware/software. There are numerous other mod authors who disable their mods for x64: I suspect these are mostly concentrated around those who change gameplay in major ways, because they are more prone to getting bug reports which stem from x64 being unstable.

Ensure center of thrust is always in line with center of mass, which for the most part means "build symmetrical rockets dummy". SAS (press T to toggle, F to activate for a moment) stabilizes your craft in its current orientation. As mentioned: watch for CoM shifts as fuel is burnt, and disable gimbals on any engines placed ahead of CoM. Otherwise, a simple picture of your lander would help a lot.

Completed my first manned Mun expedition in 6.4x Kerbin. Maximum G-load on reentry: 5.7 gees. Remaining ablative heatshield material: too little for Bill's nerves. Delta-V remaining at Kerbin aerobrake: a hilarious excess thereof. Most heat-sensitive part on the landing stage: the landing legs (and not the tanks which still had fuel in them). Aerobrake temperature: almost enough to fry the other parts. The view? Amazing.

Press F3 to pull up the flight results screen at any time.

When I've got a spot of time in the next few days, I'll try to whip up a table of fuel mass/cost ratio, probably ordered by rank of tank size (small ones are probably more expensive), but a procedural fuel tank with the approximate volume of a Rockomax Jumbo-64 cost about 1/40 of a Jumbo-64 tank. If so desired, I'll also include KW Rocketry tanks, which appear to be in the same ballpark as stock tanks. You might then add multipliers for tank type: relatively cheap default-type tanks, and expensive specialized tanks (particularly the balloon tanks*). *God bless balloon tanks for their almost ridiculously lightweight construction.

First off: do the tutorials. They help, they really do. KSP is not a first person shooter: it is literally simulated rocket science. Second, getting to space is easy: just go up. Getting to orbit is much harder: in KSP, you spend about equal effort going sideways as you spend going up, whereas in the real world, you spend far, far more effort going sideways than upwards. Third, there are two main characteristics of a rocket stage: delta-V, capacity to change velocity, and thrust-to-weight ratio, which is how much your rockets push divided by their weight. As mentioned, in stock KSP, you need about 4400-4500 m/s of delta-V to reach orbit. Delta-V comes out of the Tsiolkovsky rocket equation: delta-V = G * Isp * ln(full mass / dry mass). G is Kerbin surface gravity, 9.82 m/s^2, Isp is specific impulse, how efficient the engine is, ln is the natural log function (this is an evil demon who feeds on the tears of KSP players), and the full mass / dry mass essentially means that, the greater the ratio of fuel to other stuff, the farther you go. The G * Isp term comes out to equal how fast the exhaust gases are traveling: engines which propel their exhaust out faster get more delta-V out of each kilogram of propellant. The reason we use G * Isp instead of just exhaust velocity is that scientists in different countries got frustrated by constantly converting specific impulse between meters/second and feet/second, divided by Earth's surface gravity, and got a measure independent of which set of units you were using. The natural log function is one which steeply decays: when the ratio of full/empty mass is close to 1, you get almost linear delta-V increase (going from 5 kg of propellant to 10 would almost double delta-V), but when you start getting big ratios, you see decreasing gains from adding more fuel. More on this later. Thrust-to-weight is crucial during ascent: you need to get to orbital velocity as fast as you can, because the longer you spend screwing around at suborbital velocities, the more delta-V you lose fighting gravity. However, you also have to account for two things: atmospheric drag and engine mass. Atmospheric drag increases with velocity and decreases with altitude. As it turns out, for the vertical part of your ascent, the ideal speed is terminal velocity, where the force of gravity exactly equals the force of atmospheric drag: have less TWR, and you waste fuel fighting gravity, have more TWR, and you waste fuel fighting atmospheric drag. You also have to account for the mass of the engines: in the rocket equation, the rocket engines are dead mass. As such, it favors having lighter weight engines, even at the cost of TWR. How it usually shakes out is that you want your launch to be a little bit short of 2.0 TWR, throttle your engines to maintain terminal velocity (which will go up as atmosphere gets thinner), and then have progressively less TWR as you go up stages and have less need for thrust: once you're most of the way to orbit, you can coast on any remaining upwards velocity, and the fact that your suborbital horizontal velocity will reduce the effective amount of gravity that you feel. The last thing I'm going to say (this is going on rather long) is a bit on staging. You know that ln(full / empty mass) term? There is a theoretical limit, which is determined by the mass of a full fuel tank divided by its empty mass: in stock KSP, that ratio is 9:1 for the most efficient fuel tanks (KSP fuel tanks are much heavier than real-world counterparts). The solution to this is staging: dumping off empty fuel tanks and thus resetting the rocket equation. This usually means dumping off engines as well: this is a blessing and a curse. It is a blessing because engines are dead weight, and you do not need as much engine mass for your next, lighter-weight stage, and it is a curse because now you've got to add new rockets for your next stage. There are funny schemes like asparagus staging and onion staging which play with this a bit, but for now, simple staging should suffice for your first rocket. There are vertical decouplers like the TR-18A which dump off stuff below, and radial decouplers like the TT-38K which let you dump off engines attached to the side of that part. Both are useful. Finally, throw out the advice I gave you regarding launch TWR if you ever install FAR or NEAR, two mods which make aerodynamic drag much more realistic. In stock KSP, drag is proportional to the mass of a part, which is a stupid approximation which lets you get away with stupid launch profiles: its sole advantages are A: it's simple and forgiving for new players, and B: it exists.

Some contracts will ask you to use parts you haven't researched yet: once you complete the contract, you are no longer able to use the experimental part. This can be abused if the contract asks for you to use a part you really want to keep: just don't complete the contract until it's about to expire (or until you're about to research the node anyways). As for the straightness of your flights: is thrust perfectly in line with CoM (Center of Mass)? Are you using SAS to stabilize your rockets? Are there aerodynamic control surfaces in weird places? Are your aerodynamic control surfaces properly placed on the bottom, as far behind CoM as possible? If you haven't done the tutorials, you should, because they are rather helpful for getting down some of the basics.

It should work without other mods. I was just trying to eliminate a possibility. And point out that procedural fuel tanks cost way less than they should.

Did you at all install Real Fuels? Real Fuels will force you to pick your propellant (easiest way is to slap an engine underneath, toggle the engine to the desired fuel, right-click the fuel tank, and press a button to automatically fill it with the appropriate propellant mix). It'll also reduce the costs of fuel enormously to be more in line with reality, where fuel costs are basically pennies compared to the hardware. That said, the cost for procedural fuel tanks seems way out of proportion with other tanks: KW tanks and stock tanks are costing ~40x more per volume than procedural fuel tanks.

The costs are variable dependent on configuration. Click the action groups tab up at the top, click on the parachute, and you get options to toggle size of case, material and size of parachutes, autodeploy altitude/pressure*, and other things. Once you click "set parameters", the cost and mass of the parachute will adjust itself based on how big the parachutes are. *If you play with Deadly Reentry, for the thousandth time, don't deploy your parachutes until you're below 200 m/s on Kerbin. It can go a bit higher on light atmospheres like Duna, and slower in Eve's "thou shalt not return" atmosphere. Look up the Apollo parachute deployment profile for a good guideline. I tend to set auto-predeploy at 6-7 km, and full deployment at 500-700m.

You might have a pop-up the first time a parachute burns up, with an option to disable the message in the future? Perhaps have an info window with ambient temperature, shockwave temperature, maximum part temperature (hottest part on vessel), ablative material remaining, and an estimated safe parachute deployment temperature*? *Having a nice display window would be pleasant anyways, so I don't have to leave my heatshield right-clicked on reentry.

Where's the heatshield? You might need a 2m heat shield (because the lander can would poke out from a 1.25m heatshield, and 1.5m might not be enough), but it generally helps to have a heatshield. Also, I would suggest placing the goo pods on the top or bottom of the lander can so as to better tuck them in towards the centerline: if placed simply radially, they extend outwards uncomfortably far

I'm pretty sure a straight up/down path is not representative of reentry. Your vertical velocity in true reentry is kept quite manageable by dint of being a noticeably suborbital path, and a decent lifting re-entry can help keep your reentry shallow: the final contributing factor is the fact that heat shields are not the most aerodynamic shapes in the world. In a straight-up-and-down path, though, there is very little to arrest your descent, so you wind up plummeting far faster than you would in a true reentry trajectory. Either an overly steep reentry or you're trying to land an absolute monster. If the second, consider a partially retropropulsive descent: stick a rocket engine behind the heatshield, and fire it just long enough to dip down to ~200 m/s. The ullage motors from KW Rocketry look promising, though I wonder if there are other mods which have very-beefed-up Sepratron-like solid rockets. The stock Mk. 25 is a drogue parachute: it fully deploys sooner than main parachutes (by default 2.5 km up), but does not have as much diameter and fully-deployed drag as a main parachute. It is intended to further slow down heavy cargos before main parachutes deploy.

If it's a manned capsule, I'll often put important things like parachutes on the slope of the manned capsule, tucked away from re-entry burn. DRE has caused me to find really interesting ways to tuck the goo pods on Stayputnik cores very close to centerline. Other than that, though, a heatshield 0.25m wider than the rest of your craft should be more than enough to protect most things, at least if you're being careful not to deviate more than 5 degrees from surface retrograde. Procedural Parts has such heat shields. If you're worried about aerodynamics, I usually put a fairing over my capsule anyways, because even little things like batteries, parachutes, and solar panels are often more than enough to cause aerodynamic drag and instability in FAR*. A picture of your reentry vehicle would help in diagnosing the problem. *One thing I would recommend in order to get a sense of this is micro-rocketry: try to get a Stayputnik core with a token payload to orbit on the smallest rocket possible, which will make you really see aerodynamic issues. Despite putting only 6 OX-STAT solar panels, three batteries, a thermometer, an antenna, and a MechJeb case on the Stayputnik core, that was far more than enough to cause my 4 tonne rocket to swing wildly until I put a fairing over it (ballooning the mass to 6 tonnes, but what can you do?)

The only thing I can think of is function limits from calculus: the limit of some function as it approaches 0 from the negative side may be different than the limit as you approach from the positive side. One such example is f(x) = 1/x: it approaches negative infinity as you approach from the negative side, and positive infinity as you approach from the positive side.

Can't tell you for certain what the issue with Mechjeb is, but the stupid possibilities: #1) You haven't specified a spot for it to land. #2) It's refusing to land because it doesn't do well with an eccentric orbit. It is best to start your landing from a very tight (~10 km) circular orbit, as that minimizes loss to gravity drag.

There is one other conclusion of the rocket equation: The ratio of full to empty mass determines what your delta-V is. If you have 0 payload, and ignoring the mass of the rocket motors, there is a theoretical limit, determined by the mass of a full fuel tank divided by its empty weight. The weight of rocket motors also plays into this: in order to maintain a given minimum TWR, you must have X mass of rocket motor for every Y mass of fuel tank. The fact that you do generally have payloads further reduces this ratio. The solution is staging: ditching empty fuel tanks (and the rockets powered by them) to start the rocket equation anew. While it does mean you must add more mass for the new stage's rocket engines and for the staging equipment, removing the prior stage's empty fuel tanks lets you reset that above ratio. It additionally has other benefits: once you're in upper atmosphere, you generally don't need as much TWR, so you can get away with proportionally less powerful engines, and sometimes more fuel-efficient vacuum engines*. *Hydrogen-liquid oxygen is the fuel mix of choice for many upper-atmosphere rocket stages, but hydrogen-burning engines tend to have poor sea-level TWR and efficiency. As such, you will often see an RP-1 or other propellant in the first stage, with hydrogen used in the upper stages where the atmosphere is negligible and the rockets can operate with near-100% efficiency. The closest analog of this in stock KSP is the aforementioned LV-N, with its poor atmospheric performance and superb vacuum efficiency.

The problem is that you are deploying your parachutes at extremely unrealistic speeds: 400 m/s is still supersonic, and it doesn't matter what the temperature of the case is if the parachutes are being deployed into superheated reentry plasma (plus, there is a 0.25 max temp multiplier attached to deployed parachutes). For reference, the Apollo capsules pre-deployed their parachutes in reefed mode at 7 km altitude, at 70-150 m/s velocity. 400 m/s is around Mach 1.2, and the only two places I know of where parachutes have survived supersonic velocities are upper Earth atmosphere and Mars, both of which are < 1% sea level pressure. If you deploy manually, I would wait for < 200 m/s to pop chutes, else about 6-7 km is a reasonable place to have your parachutes autodeploy. EDIT: Above is for predeployment, not full deployment of main chutes. That should be around 500-900 m altitude. Again, if you're uncertain, real-world figures like the Apollo capsules are a good starting point.

You guys realize the parachute doesn't necessarily need to survive to fulfill the contract, it just has to be staged at the appropriate altitude/speed range? You can use different parachutes to return the rocket safely, but you are perfectly able to stage parachutes while going upwards (or downwards, but that also has its risks)

For a delta-V spreadsheet, just plug in 9.82 (Kerbin gravity) * Isp * ln(fueled mass / dry mass), and the output will be in m/s of delta-V. I'd use sea-level Isp values* for the first stage, and vacuum Isp values for the second stage and onwards. It's not 100% accurate, but short of simulating your flight path and integrating the rocket equation yourself with variable Isp, it's reasonably safe to assume your first stage will get you into near-vacuum. *Rockets are less efficient when they have to push against atmosphere. This is particularly noticeable with the LV-N atomic rocket, whose Isp goes from 200s at sea level to 800s in vacuum. I don't think KSP will model continued Isp loss in atmosphere thicker than Kerbin sea level (such as Eve's atmosphere of doom), but I'd have to double-check that.

I'd call it a bit of an exploit, but since you can get such ridiculous returns on any atmospheric engine test anyways (slap other rocket onto rocket to be tested*, reach appropriate height, trigger, pop chutes and recover everything but fuel), it's not one I overly care about. *For extra efficiency, if an engine is the last one to be tested on that flight, I drain its fuel almost completely dry.