Bigger sized rockets with new aero?

[bakanando]

With the introduction of the new stock aero the Age of the Pancake is going to start its decline, or at least it won't be as useful as before. The problem is that pancaking, asparagus staging and some other crazy contraptions were used because of the lack of even bigger rockets to send stuff to space. Anything below around a hundred tons to LKO will probably be alright, but monolithic launches for Jool-5 or other big stuff will probably not be able to reach orbit on one piece efficiently.

This types of missions could probably be done in smaller batches and docking in orbit, but there are some missions that require big launches in atmosphere as in the case of Eve. I know the Evian atmo will be changed too, but that doesn't mean it will be a lot easier to get out of than it is right now.

To fix this, do you think we will get bigger rocket parts or other tweaks that will make this kind of missions doable without recurring to asparagus/pancakes?

[UmbralRaptor]

Reminder: single ring asparagus works fine in FAR, and without extra changes, launches from Kerbin and Eve will get free payload (or can easily be shrunk) due to the reduced ÃŽâ€V requirements.

[panzer1b]

Im already working on a 500t lifter to replace the annoying pancake/radially staged rockets ive been utilizing to lift capital ships. now with the fairings, im HOPING that ill be able to enclose an entire capital ship inside a fairing, making the common puller rockets redundant (anything with alot of wing armor needs a puller rocket or itll flip instantly). My new lifter is just a massive and i mean massive 2-3 stage launcher, with a heavy amount of part clipping, as from my experience its impossible to make a super massive (eg 500+ton) lifter utilizing a vertically staged setup.

Still, i dont believe its going to be a major issue, as pankakes will still work, they will just be way less efficient then vertical designs. I think the common 6 sided asparagus rockets will still be plenty viable, and really with new aerodynamics cutting drag for heavy objects, i think 90% of designs will benefit. really the only designs that will suffer from new drag are excessively flat things with no nose cones. Then again, considering pankakes/assymetric/completelyinsane designs work in FAR with some balancing, i fail to see why they wont in teh new stock aero in 1.0.

[Renegrade]

Almost all rockets get more efficient with less fake air. For example:

That monstrosity made it to orbit just fine under FAR, despite being mostly drag and having less than 4k delta-v (the drag-inducing tanks were empty, they're just there to make drag).

You'd have to make something completely insane for it to actually be worse than stock air, as stock air basically meant that every part was out in the airflow by itself with a Cd of 0.2 (as it derives cross-sectional area from mass).

So people will still be able to asparagus-spam themselves into orbit, just they'll be taking a small penalty to do so.

Note that you can cluster tanks and engines in a serial staged design for some really heavy throw weight, bigger parts are not necessary (I think I was putting 300-500 tons in orbit under stock air in BTSM prior to the launchpad restrictions using 2.5m parts exclusively). The Far-Cross design above is an example of serial staging.

[Van Disaster]

The problem with crazy stuff in FAR is mostly keeping it pointing the right way rather than any wacky excess drag issues. I've launched things that look something like mushrooms - albeit that was quite a few versions of FAR ago - because of the gigantic fairing, but that kept them aimed right. On the other hand now making rockets that look like rockets is sensible, people can try out all those crazy ideas from the 60s.

[samstarman5]

Keep in mind that along with the atmosphere getting thinned out a bit, the engines are also getting nerfed. So I wouldn't get too eager to decide on new ship assemblies just yet.

[bakanando]

Well, I launched this with a standard looking rocket (even if the payload is not standard, lol) but it's somewhat below the max amount you can lift with a sole SLS engine and a couple boosters.

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It might be possible to lift bigger stuff with the new stock aero even with the thrust adjustment, but I'd really like bigger sized rocket parts for big launches.

It looks more plausible, has less parts, and would reduce asparagus staging a lot.

[Daze]

Instead of bigger diameter parts it would be perfect more variety on engine side

[Jouni]

My standard rocket for launching heavy payloads in FAR has been six 3.75 m boosters around a 3.75 m core. Even without any fuel lines, it can launch around 500 tonnes to LKO (or 200 tonnes to orbit Tylo). I hope that 1.0 nerfs the engines somewhat, because you shouldn't be able to launch huge payloads with simple rockets.

[bakanando]

@Daze The variety of engines is indeed limited right now, the game lacks in engine's ISP between 390 and 800. Some engines with ISP of 400-600 in the 1m or 2m size parts would help the game have more variety, even just a bigger 800 ISP engine would help. Having bigger parts and a greater variety of engines are not mutually exclusive, though. I understand that by adding more parts you reduce the performance of the game, but many parts have been added in recent updates anyway so that doesn't seem to be a good reason to not do it.

@Jouni The engines are indeed "a little bit" off in TWR compared to other LOX engines, but nerfing the engines without adding anything bigger would only reduce your payload weight to LKO. This is not a good option if you are not intending to compensate it with anything else, thus the request for larger diameter (5m, maybe) tanks and engines. A 5m payload bay/fairing would be nice too.

The only problem I find is that when they fixed the size of the SLS parts at 3.75m there are not many bigger engines IRL that can work as comparison to make bigger engines without making them absurdly OP.

5m sized SaturnV engines and tanks anyone?

[WWEdeadman]

Guys, just saying, we didn't build the ISS on ground and shoot it up as a whole either. If you want to get something huge to orbit, how about you split it up and dock it in space. Also, as long as you use nosecones Asparagus staging isn't any less efficient in FAR, as far as I know, so it won't be in the new stock aero either, I guess.

[Torquemadus]

If the new stock aerodynamics breaks lots of pancake lifter designs, will it be called aerobreaking?

[Chaos_Klaus]

Radial boosters are a thing with FAR, hell even in real life ... why should that change in 1.0? It's so funny how everyone gets so scared with so little informatnion to go on.

I really think that the changes to ISP caluclations (resulting in lower atmospheric thrust) will change lifter designs more than drag stuff.

Given the fact that you can build hugely overpowered rockets in ksp, there is really no need for concern.

[Temeter]

Pancakes will live. They are actually still easier in FAR than they are in Stock. Just try to stay subsonice until you get to 20k, and you'll easily get a brick into space. While your craft requires a bit more Dv (i needed ~3800 instead of ~3300), the requirement stays under stock (afair was 4800 Dv). And FAR is relatively aggressive.

All in all starting rockets should get easier.

[Windspren]

Don't tell Jeb about bigger rockets...

[waterlubber]

Honestly, I hope this update just encourages nosecone use. AFAIK, the devs are looking not to penalize players who have already existing ships, just to increase the reward for aerodynamic designs. With FAR, not only do you need to worry about simple drag, but also things like turbulence, etc.

Another thing I hope the devs do is boost the thrust of the NERVA in space, since it'll be next to nothing in atmo.

[Daze]

With FAR, not only do you need to worry about simple drag, but also things like turbulence, etc.

http://en.m.wikipedia.org/wiki/Turbulence

Actually no

[Renegrade]

I really think that the changes to ISP caluclations (resulting in lower atmospheric thrust) will change lifter designs more than drag stuff.

That won't hurt all that much, I play with KIDS with the "new" ISP calculations already (and also BTSM which has that built-in). Just don't build your first stage out of nervas, kay?

The only time that might cause any REAL issues is when you're deep in Eve's atmosphere.....

[bakanando]

It seems the concensus is that as long as pancake exists there is no need for bigger rockets. I don't understand where that logic stands, but this is going nowhere.

[Random Tank]

The problem with crazy stuff in FAR is mostly keeping it pointing the right way rather than any wacky excess drag issues.

This is also a non-issue with proper piloting. Tilt over a coupe of degrees at 500m or 100m/s and then keep your heading marker inside the prograde marker until you're in orbit; that will prevent 99% of flips, even with pancake rockets. Struggling to keep your heading on that prograde market? Then your TWR is either too high or too low; 1.4-1.5 is a great number. It's actually really simple...

Another thing I hope the devs do is boost the thrust of the NERVA in space, since it'll be next to nothing in atmo.

Wat.

If they're gonna do anything they need to LOWER the thrust of the LV-N; it's designed for circularisation and transfer burns; if you're using it on a lander or launch stage, you're doing something severely wrong. The real life NTRs had a very low engine TWR; the American NERVA being about 1.5 and the Russian NTR being about 1.8; the KSP NTR is 2.6, which is ridiculously high supposing that engines in KSP traditionally have much lower TWR than their real life counterparts...

Granted, real life NTRs are slightly more efficient than KSP's; I wouldn't even mind if that got this efficiency boost in KSP if their TWR was nerfed...

[Frozen_Heart]

American NERVA being about 1.5

Later US NERVA designs reached TWRs of 7:1. The KSP LV-N is heavily weakened compared to real life ones as is.

[Random Tank]

Later US NERVA designs reached TWRs of 7:1. The KSP LV-N is heavily weakened compared to real life ones as is.

Source? The only designs I can find are the Nerva, with 257kN of thrust; and the Nerva-2, with 333kN; supposing they both weigh around 22T each; that's TWRs of ~1.2 and ~1.5 respectively...

Besides, comparing the LV-N to the NERVA is silly anyway, as the NERVA is a good 5-6 times larger than the LV-N; most KSP engines are about half the size of a Real life equivalent. It's much better to compare the LV-N to the Russian NTR (the RD-0410), as that is 1.6m wide and weighs 2 tons, very similar stars the LV-N... Apart from the fact that the LV-N has nearly double the thrust! The RD-0410 does have 910 seconds of Vac ISP though.

I support changing it to these stats as a TWR of barely above 1 makes it much less of a "jack of all trades, master of all" type of engine.

[kStrout]

I would actually be glad if they broke most pancake designs, I always spend time and effort making a rocket that is efficient, powerful enough and looks like a rocket for my launches. I then get annoyed when other people make a giant pancake rocket in 5 mins that looks horrible but does just as well as my rockets.

[RabidMonkey]

Source? The only designs I can find are the Nerva, with 257kN of thrust; and the Nerva-2, with 333kN; supposing they both weigh around 22T each; that's TWRs of ~1.2 and ~1.5 respectively...

Take a look at the Timberwind 250. TWR over 30, 2451.6 kN of thrust.

Compared to modern nuclear engine designs, the LV-N is severely underpowered. Even at its current size.

[Renegrade]

Take a look at the Timberwind 250. TWR over 30, 2451.6 kN of thrust.

Counter-quote from http://en.wikipedia.org/wiki/Nuclear_thermal_rocket

From 1987 through 1991, the SDI Office funded Project Timberwind, a non-rotating nuclear thermal rocket based on particle bed technology. Although the project was canceled before testing in 1992 by the incoming Clinton Administration, the design was thought to achieve thrust-to-weight ratios of 30:1 and specific impulses of at least 1000 seconds.

Lack of test firings of a Star Wars engine makes me rather suspicious. Did it really reach those specifications in calculations? Would it have reached those specifications as a physical prototype? Did it even exist at all?

Compared to modern nuclear engine designs, the LV-N is severely underpowered. Even at its current size.

Ditto for the chemical engines as well though. Modern chem engines can go up to 150 TWR in actual, real, production engines - the Skipper is like 20, the Mainsail is like 25, and the LFB and x4 is like 33. Oh and the 48-7S is like 30 for some bizarre reason~

So you're looking at a downgrade of 4.5x to 7.5x (ignoring the KR-2L and aerospike engines, which are outliers on either side). Multiplying the LV-N by those figures gives us 12.2 to 20.4 TWR - which comes close to the performance of engines that may have never even existed at all, and were definitely not tested. Not bad considering the LV-N is a first-generation prototype made by Jeb's Junkyard, and not a third-generation paper study.

Note also that chem engines can reach specific impulses around 460 for hydro-lox designs, but the KSP engines top out at 370-380 for the big, high-TWR kinds and 390 as an absolute. Scale up the LV-N's Isp by that same factor, and you get 944-999 Isp.

So no, the LV-N isn't underpowered at all. It's a state of the art third-generation NTR in Kerbal scale.