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Did 1. 0 nerf SRB's too much?


cybersol
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A month ago I came back to KSP after a long hiatus -- the last time I played was before science was introduced. I must say Squad has done amazing things since then. In 0.90, one thing I enjoyed was how career mode made you make all kinds of interesting rockets with new constraints. I quickly grew to admire SRBs in a way that was never true before. They had a good chunk of dV on the cheap, and were just tweakable enough in thrust and solid fuel to let you make the rest of the rocket as recoverable as possible. This kept launch costs down, which seemed like a really good thing since that is also SRBs role in real life. However, in 1.0 the trusty BACC seems severely nerfed to me, such that there is little reason to use it over LFO.

Checking the BACCs new stats, its mass actually dropped 1.9kg (24%) while its solid fuel load dropped 30% and its atmo ISP is way down 28%. While all engines went down in ISP, the LV-T30 for example only droped 12.5% atmo ISP. Despite all those size and efficiency nerfs, its costs in 1.0 increased 50%. Further comparing it to an similar weight LFO stack the BACC is longer with a higher drag value, generates no electric charge, and is not throttable. All in all, I don't think it fill its cheap booster role anymore compared to 0.90.

In some ways this will be good, as the one true way to build a rocket will again be thin LFO vegetable style.

Cheers,

CyberSoul

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Besides reading stats have you actually played the game in 1.0? Because to my understanding and from actually played, they did some major modifications to the physiques engine and how ISP works in vacuum. Some of the stats have gone down but they actually perform better/more efficiently/different than previous when in a vacuum.

So far, SRBs to me feel buffed if anything with the new atmospheric changes. A single SRB takes me all the way into space and then some beyond 200km out! The LVT-45 also feels more fuel-efficient now in space, a lot of the engines do actually. I suggest you just try some of them out and see how it actually "feels" in the game besides what the stats say.

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I have played and tested, SRB are pretty pointless now as first stage, one benefit is that the TRW spike then they start to run dry is less of an problem however the ISP nerf make them far less effective and the price jump make normal stages better, liquid fuel boosters can also use crossfeed.

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I don't think they've been nerfed, or like Sedativechunk said, you really need to fly them and see how they work for you with the new aerodynamic model, rather than just comparing stats.

I suspect they'll benefit a lot more from thrust limiting than they used to. Depending on how heavy your rocket is, an un-tweaked SRB might be putting out more thrust than you actually need off the launch pad.

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Up until v0.90 the aerodynamics model had problems

With v1.0 nosecones reduce drag.

I have never played a full career, just science, but there are so many changes because of the new aerodynamics. I am worrying about electrical power more than DeltaV

More Batteries! That's Jebediah's new watchword.

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Besides reading stats have you actually played the game in 1.0?

Yes, I tried them in early career mode and they are much less useful than they were in 0.9. Indeed even before fuel lines, parallel LFO stacks outperform the BACC even before you can asparagus stage. Its sad, because I finally had a use for them in the last version, but not in this one. RIP BACC.

One benefit is that the TRW spike

The TRW is their best feature now, but the need for TWR also seems much more forgiving now in the lower atmosphere.

SRBs make superb first stages with the new aerodynamics, and that's the way it should be if you're going for realism!

They were great for me in 0.90, but honestly in 1.0 I've gotten better results with LFO and the old tried and true asparagus.

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  • 2 weeks later...

I'm a little late to this one, but I just wanted to add that I feel as though the SRBs have not only become much less useful, but much less fun to use. It's not that they're useless, but relative to actual SRBs, with their high thrust/TWR, and relatively lengthy burn times, KSP's SRBs don't act like SRBs anymore, and they aren't really worth messing with as they currently stand.

Having your SRBs assist you through the first 8-10,000m is helpful, however having to jettison BACCs 25 seconds into flight, completely burnt out at an altitude of perhaps 3-4000m, with 66,000m of soupy atmosphere left to punch through, not so much.

Furthermore, the models and their stats simply don't add up. They're all over the place really, and it's not just the SRB's. A notable example off the top of my head is the recently increased fuel capacity of the Oscar B tank...according to it's physical size it should have roughly 1/7 to 1/8 the volume of the T-100, but it now boasts fully half the capacity of the T-100. As for the SRB's, I'm not sure why they've been assigned such arbitrary values, but this coupled with the recent nerfing has totally killed them for me.

Just check out the wildly varying fuel capacities...evidently fuel capacity and physical dimensions aren't related.

NGg8t2nh.jpg

According to their physical size, the RT-5 is roughly half the length of an RT-10, which is roughly 40% as long as the BACC, and the BACC is slightly more than half as long as the KD25K. Therefore, as you can see, the values assigned to them are seemingly rather arbitrary. Perhaps the smaller 3 can be forgiven their relatively minor inconsistencies, but the KD25K is just plain nuts. In fact, it seems as though all of the NASA parts were just thrown in to the game without much thought. They're better now, but given that it doesn't really take that long to balance part .cfgs, I don't know why they were/are such a mess.

Anyway, I'm adding my voice to the chorus of boos over the handling of solid boosters. =)

Edited by little square dot
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Personally, I'm using a lot more SRBs in early career mode than ever before, and more in mid-range career mode. They don't feel overly nerfed to me. I'm using them for things similar to their real life uses. As a primary first (and occasional second) stage for light payload, to help low TWR craft get moving faster off the launch pad, or to get liquid fuel stages up high enough that their efficiency requires. If the craft might be able to use SRBs, I always try and compare prices, and they usually come up cheaper than all-liquid designs for those kinds of uses.

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I only find the KD25k of any useful value, but even this one could see a longer burn time as I don't even use it unless the launch vehicle is light enough to have it cut its thottle by half to get 90 seconds of burn. (I'd warrant for the 127 burn time of the SSSRB.) The only good reason to use SRBs now is TWR, which is really good for their size.

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I don't think they are nerfed too much, I think we are missing one. Build a Mk3 shuttle, put those SRB's on it, then look at a picture of the real space shuttle. Do they look a little small to you? They are, we need a size up.

9D3033FC34C48C502CF33589617CF79CFB8DB4B8

STS120LaunchHiRes-edit1.jpg

Edited by Alshain
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I try to use SRBs as my first stage/boosters. My problem is that the big ones are more expensive than their equivalent liquid fuel stage. They also have worse Dv than the liquid fuel stage. So there is literally no economic or efficiency reason to use the two big SRBs.

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I personally find myself using SRBs a lot less than I used to. My last major career mode run was in .25 with RemoteTech, and I used SRBs excessively. I had a dedicated commsat launch vehicle that felt a bit like an ICBM - it had three solid stages. A BACC, followed by a RT-10, followed by a vacuum optimized solid upper stage motor (from RLA Stockalike). It lifted dozens of unmanned craft in a reliable, cheap fashion.

Now that I play career in 1.0, and I have launchpad weight and part count to pay attention to, I find that SRBs are often in the way. A rocket similar to what I used before, BACC + Hammer + Flea + payload, cannot make it into orbit anymore. I could add more SRBs, but here's the thing... a LV-T30, a couple fuel tanks, a LV-909 and another fuel tank weighs less, has the same part count, and costs just about the same amount of funds. And that DOES make it into orbit just fine. So it feels like I'm paying less funds for expendable launches and have less to worry about building constraints if I just use liquid fuel.

So I've pretty much migrated to all liquid fuel now, at least for small rockets. Maybe the big ol' Kickback booster will be cost effective in assisting 2.5m rockets because liquid fuel tech scales exponentially in cost? I don't know, I'm not there yet.

...But then again I could use 1.25m liquid fuel boosters, so probably not.

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I only have a problem with cost. To get the same performance, I always end up needing a more expensive rocket if the first stage is solid, which is stupid since the liquid has further advantages like throttling and lower takeoff weight. IF they were a bit cheaper, I would use them again, in fact I often try, but sadly KER always convinces me I'm wasting money when I do.

Then again, I am closing on a SSTO booster family... hard to go cheaper than >90% recovery (if landed within a 500km radius of KSC).

- - - Updated - - -

I don't think they are nerfed too much, I think we are missing one. Build a Mk3 shuttle, put those SRB's on it, then look at a picture of the real space shuttle. Do they look a little small to you? They are, we need a size up.

http://images.akamai.steamusercontent.com/ugc/39748930606083227/9D3033FC34C48C502CF33589617CF79CFB8DB4B8/

http://upload.wikimedia.org/wikipedia/commons/d/d6/STS120LaunchHiRes-edit1.jpg

Oh yeah, and the 2.5m SRB. Like yesterday. Maybe a 0.625m one too while we are at it?

Rune. MOAR BOOSTERS!

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We need an update to the stock fairings, that would allow us to fire 'stowed' engines :P this way, starting from 1.25m fairings, you would be able to hide several

srb's inside a fairing of the diameter you want :) (would also allow to have a variable thrust curve, with some of the SRB's burning out sooner than others)

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I don't think they are nerfed too much, I think we are missing one. Build a Mk3 shuttle, put those SRB's on it, then look at a picture of the real space shuttle. Do they look a little small to you? They are, we need a size up.

I fully support a drive for a 2.5m SRB.

After more experience with version 1.0 SRBs, I still think they under perform relative to their ideal role as a cheap first stage. The BACC I only use when I need to save part count in early career as its really not that cheap now for what you get. The Kickback I occasionally use because its cheap, but its niche is small because it needs more power. The smaller ones are practically useless for me now.

To fix the balance, I would personally do the following:

1) Add a new late game 2.5m SRB (2-2.5k thrust for 60-90 seconds) when 3.75m parts start showing up

2) Give the Kickback 50% more thrust (1000 max)

3) Give the BACC Thumper back its 0.9 weight and fuel load (30% more fuel) at its current 1.0 increased cost

4) Increase SRB ISP by about 10-15% across the board

Cheers,

CyberSoul

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That would certainly explain why my working rockets from .90 didn't work in 1.0. SRBs for me just feel less powerful. And now that you mentioned the price has gone up, it seems like they are pointless. Besides, I have already stopped using them in my career save.

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So far, SRBs to me feel buffed if anything with the new atmospheric changes. A single SRB takes me all the way into space and then some beyond 200km out! The LVT-45 also feels more fuel-efficient now in space, a lot of the engines do actually. I suggest you just try some of them out and see how it actually "feels" in the game besides what the stats say.

Actually the only liquid fueled engines that are more efficient in space in 1.02 compared to 0.90 ar the LV-1 and LV-1R. Even the poodle's weight loss doesn't compensate for its reduction in Isp in most cases.

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If you simply put 2 SRBs left and right without nosecones the additional drag WILL cost you. People have been building rockets way too crazy all the time because there was no aerodynamic, now that its here some ppl have a rough awakening

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Hmm, looking at the stats now... I may have to rethink the way I've been using them. I was still in the mentality that SRBs = cheapest way to get dV on an atmospheric stage... but they do kind of suck.

As I see, it, the largest SRB (also the best, no?) has 3x the thrust of a LV-T30 for 2x the cost...

SRB fuel is 0.6 per unit.

LFO mix is 0.459 per unit... (using LF at 0.8 per unit and O at 0.18 per unit, in a 0.9:1.1 ratio)

The only advantage is a cost advantage for thrust... but it seems that cost advantage rapidly disappears when you start needing dV.

I still need to look at the cost of the fuel tanks themselves...

It seems the mainsail is less cost effective in terms of thrust per cost than the LV-T30 (unless the wiki stats there are still out of date)... so I don't know about the pricing.

But for the Isp.... Lets look at the real world, vacuum stats:

Kerosene:

http://en.wikipedia.org/wiki/NK-33

Specific impulse: 331

LH2-LOX:

http://en.wikipedia.org/wiki/Space_Shuttle_main_engine

specific impulse: 453

Solid fuel:

http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster

specific impulse: 268

The current Isp values we have are more or less comparable with Kerosene propellent....

Or we could assume that as dV needed to reach places is less, they scaled down Isp.... or the LF is generic, and different engines are meant to represent use different propellants.

Anyway... the best LFO engine we have in game: 350s

The best in RL: 453.

350/453 = 0.77267

Take that scaling factor, multiply it by 268... = 207

SRBs should get at least 207 vacuum Isp, to be "realistically scaled" relative to LF engines, assuming some LF engines are using LH2

If we assume Kerosene, no scaling is needed, and SRB Isp should reach 268...

Edited by KerikBalm
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Hmm never really thought about using a SRB in space.

I do use them very early in the game till I can use a liquid core.

The inherit problem with SRB is you waste fuel do to aerodynamics, (you need full thrust to get off the ground but then that extra power is wasted as the rocket pushes against aerodynamic drag.)

So basically I use them like they are used in RL. (I add them to a liquid core rocket to add some extra power or to get the liquid core off the ground.)

As far as cost. Well when you add in all the parts for a liquid fuel rocket they are cheaper or on par.

Where they really shine is early in the game where you are pushing against the rocket part counts till you upgrade.

For those number crunchers out there don't forget to factor in mass.

SRB are designed to burn fast and hard then you drop the mass of the SRB container and continue on.

Liquid tanks tend to stick around a lot longer and as such the mass stays with you.

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