NathanKell

You'd have to hand-edit the part cfgs, not the savegame or craft file, but yes, you certainly can do that editing. Edit the pod's, the tank's, and the engine's part cfg files and there you go.

Thanks pal. Glad you're sticking around.

That seems fair.

Yeah, to use them you have to make sure your engine is using ModuleEnginesRF and you have to tell it to have ullage = true and ignitions = (number of ignitions desired). Setting engines to pressureFed = true means they must be fed by a RealFuels-enabled tank of type Fuselage or ServiceModule.

Cray/Mike Miller calculated it at as a millimeter or so for most WarShips, yeah. As for fantasy...well, I'd argue on that one. If you get rid of the step functions and old "simplified for pen and paper" stuff it works reasonably, space-wise. But on the ground things are fantasy, yeah. 95 ton robots that run at 86kph aren't scary, they're targets.

http://b14643.de/ look at the various Atlas pages under the US rocket pages. http://spacelaunchreport.com/atlas.html http://heroicrelics.org/

Woo! (Points at name.) Brachistochrone trajectories are real things. Indeed, pretty much all of BT's space physics are legit, except for ludicrously impossible Isp (on a straight-up calculation, the exhaust velocity of those drives is over lightspeed...) and of course the KF drive.

They should all be fixed in 1.0.5. Stock parts, that is, mod parts...heh.

And, happily enough, as I said in this very thread it's not an SSME stat-wise. It's an RD-191 equivalent. Because as regex pointed out, in (stock) KSP it is literally impossible to have an SSME equivalent; the entire point of an SSME is that it is a high-efficiency sustainer that requires a volumetrically large, albeit light, propellant supply--one light enough that a mere two SRBs can lift it, with SSMEs' help. @swjr-swis that's fair; I was unfairly sharp in my reply, and I apologize. My point only is, or was, that realism says "Vector is underpowered" not "Vector is overpowered".Trying-to-make-things-that-look-like-real-life-and-have-weird-versions-of-real-life-ratios says "no you must have weak sustainers" but...that ain't realism. :]

You're right, I always forget that step...

@SpaceplaneAddict I think we need to add this answer to a FAQ, it comes up every few weeks. :] No, the aerospike is not a magic engine. It can't erase the fact that nonzero pressure (very nonzero pressure, a hundred kilopascals worth of nonzero pressure) exists at sea level. All an aerospike nozzle does is ensure that you have a nearly-optimal expansion ratio at any given pressure. In effect (tl;dr) that means an aerospike will do nearly as well as it can at any given ambient pressure. So, here's the deal. A rocket engine works like this: propellants combust in a combustion chamber. That combustion has a pressure. The result is then fed through a narrow throat out into a nozzle (the thrust chamber), where it expands while going downwards. That creates thrust. Thrust is optimal for a given ambient pressure if that nozzle expands the exhaust such that, at the nozzle exit, the pressure of the exhaust is the same as the ambient pressure. However, Isp is governerned by how much expansion occurs. This means for example that a combustion chamber with low pressure works acceptably in vacuum. This is because even low pressure exhaust can be expanded lots, since ambient pressure is zero and you'll never hit that. However, a low chamber pressure engine is crap at sea level, because you can't expand very much at all before you hit ambient pressure. So that's one reason, intuitively, why rockets don't work as well at sea level: there isn't very much to expand. The second reason is even simpler (and ties into the first of course): at sea level, or indeed in any atmosphere period, the air is piushing back at the exhaust. In vacuum, nothing is pushing back, so you get the full effect of the exhaust. At sea level, there's a hundred kilopascals pushing back at the exhaust. Now, why an aerospike? As I discussed above, in order to get the optimum Isp for that chamber pressure and reaction efficiency, you need to expand the results to ambinet pressure. However, if you do that with a simple bell nozzle, you only are optimal for a single ambient pressure; at all other pressures (i.e. all other altitudes) you will either be expanding too little (any pressure lower than the design pressure) or too much (any pressure higher than the design pressure). An aerospike gets around this by varying the expansion. It will never be as efficient as a bell at that bell's optimal pressure--the "fake" nozzle is not quite as efficient as a real one, so you take a slight loss across the board--but it will be rather more efficient than that bell at non-optimal pressure. Finally, let's move to the aerospike ingame. You'll note that it basically follows the above: It is never quite as efficient as the optimal engine in any given regime. It's slightly less efficient than the Mammoth/Vector at sea level, and it's slightly less efficient than the Poodle in vacuum. However, its true advantage is that the falloff in efficiency at pressures higher than sea level (i.e. Eve) is much, much more gradual than bell engiens'. To sum up: No, the aerospike is not a Magic Engine (tm) that can someone get around the fact that at sea level there's a shedload of air being shoved at you, making chucking high velocity gas out the back less efficient. Indeed, it is not as efficient getting around that as the best bell-nozzle engine, nor would it even be as efficient as a non-optimal bell-nozzled engine which had a higher chamber pressure than the aerospike. However, it does manage to minimize the losses from having a non-optimal bell no matter the ambient pressure.

@mcirish3 I know it's a long thread, but I'm fairly sure that Claw and OhioBob and I discuss that very thing in it somewhere, and OhioBob even posts some helpful graphs.

@legoclone09 I do read threads you know, no need to poke me especially. @rocketjet787 my guess is you had a pre-1028 build and the redownload updated you. Glad it's fixed!

The thrust curve is only relative, it shouldn't cause any problems to add one.

@Kerbas_ad_astra You assume correctly! Also it's heat shield testing the real way too: https://en.wikipedia.org/wiki/Project_FIRE

If you disable realheat, do you have the same issue or is it fixed then?

@Phineas Freak that's great! Can you put that in a PR if it isn't already? I've crunching tutorials but strato has rights to merge.

@CobaltWolf yes, in fact this very mod does it.

Eh? It's more like it has the middle stage only, and some strapons. See the Saturn II studies. Saturn V is like if you took the SLS boosters and put them under the core, and didn't ground-light the core, and then added a third stage on top. 3 stage kero+hydro+hydro != 1.5 stage solid+hydro sustainer. Tbh they have little more than paint scheme in common. And not even that, now. :]

If the calculator dates to before 1.0, it's not valid. Drag changed totally.

Uh....whaa? Realism isn't "everything I don't like". As I showed upthread, realism means size isn't a good metric anwyay, and in reality the Vector would be hilariously underpowered--and a bit large for its power, too!

In addition to the considerations above, also chamber pressure. Though even at very high chamber pressure you'll always do better when there's nothing pushing back against the exhaust (vacuum) than you will when something is (any kind of atmosphere).

@MissMolly congrats!

It's possible Ven changed the gimbal name recently and we're targeting the old transform name.