Good job on the engines, Squad

[arq]

They did a pretty good job overall. Many previously-neglected engines now have a place. I do have a few remaining comments, which I'll make below:

I used to use the T45 when I needed a gimbaled engine and a T30 when I could do without, since they had comparable ISP. However, now the T45 has enough of an ISP advantage that I'm much less likely to use the T30 ("vacuum" is misleading, by 10km engines have gained 86% of their vacuum performance - in fact, the T30 only has higher ISP below 5500m). The TWR advantage just doesn't usually make up for it in most of the situations I encounter. I kinda preferred the old system where the only real difference was TWR and gimbaling (the T30 made an excellent SSTO booster), but w/e.

I'm not sure why the Ant performs so poorly in atmo while the Spider does just fine, but honestly I've never really used either in atmo so w/e. I just would have expected them to be more comparable like the Spark vs Twitch.

The aerospike may seem pretty weak at first glance, but what doesn't show up in the browser (only in the cfg) is this: All rockets lose ISP (and thrust) linearly from ASL at 1bar to 0.1% at some higher pressure (between 2bar and 12bar for the ones I've checked). However, the aerospike doesn't hit 0.1% until 20bar. So ASL on Eve an aerospike still has 75% performance. If you had cause to be ASL on Jool (I'm sure with 1.0 even the ambient heat of Jool would kill a rocket well-before it could get that low), an aerospike will still get 25% performance while every other rocket (that I've looked at) won't even function.

I tend to find SRBs a little underwhelming, but if there are other viable options I guess I only care so much. And they're still okay, considering the price.

Perhaps my only actual frustration is the growing supremacy of the LV-N as an interplanetary engine. It used to be that the LV-N had double the ISP of any other engine, but now it's even more. Now, more than ever, I wish there were an alternative or two with ISPs around 450 or 600 to fill the gap. I feel Squad has done a good job balancing most of the other engines, but there are too many situations where the LV-N is the obvious choice (it handily wins for almost every interplanetary ship too big to use an ion drive and without a high TWR requirement). It'd be nice if it had some friendly competition, or at least if it came in different sizes.

[Snark]

Overall, I'm pretty happy with the rebalancing act they've done. They've seriously nerfed some of the engines I previously used heavily (I'm lookin' at *you*, "Spark"), but truth be told, I think I needed that to kick me out of my rut.

Many previously-neglected engines now have a place.

Amen to that! There are several engines that I used to *never* use, now they definitely have their role. I specifically like what they've done to the T30-vs-T45, to the SRB-KD25k, to the toroidal aerospike, and to the LV-N. Also, I now actually have a reason to use a Poodle-- never used one before, ever.

I used to use the T45 when I needed a gimbaled engine and a T30 when I could do without, since they had comparable ISP. However, now the T45 has enough of an ISP advantage that I'm much less likely to use the T30

That, and also: gimbaling matters more now than it used to. With the new aero making it so easy for rockets to start flipping if you get more than a weensy bit off prograde during ascent, having a gimbaled engine *really* helps with stability. I used to never use T45, under any circumstances-- heavier, lower thrust, just simply not worth it for gimbaling that I didn't need. Now it definitely has a place.

The aerospike may seem pretty weak at first glance...

Yes, it got some much-needed love. First, its Isp is a lot better in comparison now (since most other engines got nerfed, and it didn't). Second, the new change in Isp calculation (to reduce thrust rather than increase fuel consumption), coupled with aero rules that favor a lower starting TWR than before, really give it a leg up. I look forward to trying it out on an Eve lander.

I tend to find SRBs a little underwhelming, but if there are other viable options I guess I only care so much. And they're still okay, considering the price.

One thing that I like a lot better now is the biggest SRB, the "Kickback". Never used to use them at all-- the super-long, thin design was just too inconvenient, never seemed to fit my designs (which tended to be low squat asparagus things), it was just too much of a hassle. The new aero rules turn that on its head-- being long and skinny really helps it, and it also fits better to my rockets (which are themselves taller and skinnier than they used to be.)

Perhaps my only actual frustration is the growing supremacy of the LV-N as an interplanetary engine. It used to be that the LV-N had double the ISP of any other engine, but now it's even more. Now, more than ever, I wish there were an alternative or two with ISPs around 450 or 600 to fill the gap. I feel Squad has done a good job balancing most of the other engines, but there are too many situations where the LV-N is the obvious choice (it handily wins for almost every interplanetary ship too big to use an ion drive and without a high TWR requirement). It'd be nice if it had some friendly competition, or at least if it came in different sizes.

I actually like what they did here. I agree with you that it would be nice for it to have interplanetary competition, but I think 1.0 made it more interesting, by making it *less* convenient in several ways:

1. A lot more massive than it used to be. This limits its usefulness on smaller ships (where the mass of the engine itself reduces the benefit of Isp).

2. Generates a lot of heat, requires more attention to ship design.

3. Runs on just liquid fuel rather than LFO. This makes it a pain to engineer if you want to have a ship that can switch between it and something else-- another design challenge.

4. New aero rules make it less attractive to mount radially during lift-off. But putting it in-line on a massive ship is awkward because it's only 1.25 m.

All of these together make it harder to use and more specialized than it used to be-- they more than outweigh (for me, anyway) its improved Isp relative to the other engines. I actually wouldn't want to see a 2.5m nuke engine unless it was significantly nerfed in some other way (really massive, perhaps), since the size/shape of the current one forces some interesting design challenges.

[viila]

Perhaps my only actual frustration is the growing supremacy of the LV-N as an interplanetary engine. It used to be that the LV-N had double the ISP of any other engine, but now it's even more. Now, more than ever, I wish there were an alternative or two with ISPs around 450 or 600 to fill the gap.

The problem with introducing an intermediate engine is the dreaded R-word. Because realistically you can't have a liquid bipropellant engine with higher I_sp than 450 seconds. That is the absolute theoretical maximum for LH+LOX chemistry. Our liquid fuel has similar density to RP-1 (refined kerosine) which puts the absolute cap at 360 seconds. A few exotic tripropellants could get up to around 500 seconds, but those are insanely nasty stuff like elemental fluorine (with exhausts containing the ever wonderful hydrogen fluoride), or combinations that no sane person would attempt (cryogenic oxygen/fluorine + cryogenic hydrogen + molten beryllium or lithium!).

I real life there just is a huge jump from chemical propulsion to nuclear propulsion. And Nerva style NTR is relatively tame nuclear engine to begin with. (Because it's limited by hopefully keeping the nuclear core solid. There are even more crazy concepts like liquid or gas core NTRs that would leak radioactivity like crazy, but would have an order of magnitude higher I_sp)

------

As to the engine improvements, I like them as well, except that we no longer have a small 3m lifter engine, nor an inline lifter engine. The Mammoth limits options since it's a cluster, so it has to be a terminal part. (Nor can we substitute the largest 2m part either, since that's a cluster as well.) We can't have anyting bigger than Mainsail inline if we need atmospheric performance which is sometimes necessary on superheavy launches since the first stage might not get you up more than few kilometers.

[maccollo]

I real life there just is a huge jump from chemical propulsion to nuclear propulsion.

You only get NTR with ISPs close to 1000 if the fuel is hydrogen. The kerbal NTR should really have a lower ISP since it uses a hydrocarbon fuel.

[Eric S]

I think they did a good job giving each engine a nitch. I think I've used every non-radial engine and SRB except the 48-7S and LV-1 multiple times. And yes, that includes the flea, though it gets the least use. Once I've got enough science parts to make it worth it, I wind up using the RT-5 for a few near-KSP biomes on a suborbital biome hopper. The RT-10 tends to get used as a second stage on my suborbital and lighter orbital craft. The rest of the SRBs get used during the first stage, either alone or to help a liquid main engine get up to a better altitude, or occasionally just to get it up to speed faster.

[FleshJeb]

Now compare the Ant to the Spider. I think that was a POOR design choice.

[Jarin]

The Shuttle SRBs were VERY heavy. The two SRBs constituted 69% of the shuttle's take-off weight. They also didn't have very good ISP, at 237 (sea level) to 269 (vacuum).

The Kickback's ISP is a bit low, but it might not be heavy ENOUGH.

That would be fine... if career progression wasn't so very locked to launch weight. Your potential delta-v/mass ratio there makes them... less than useful.

[Temeter]

I like the engine balance, every single one has it own quirks and there isn't really any bad engine.

Btw, did anybody noticed they Aerospike got stealthbuffed? 340 ISP in VAC now and 180 thrust at 1.5t weight. It's actually a quite good vacuum engine now too.

Now, more than ever, I wish there were an alternative or two with ISPs around 450 or 600 to fill the gap.

You might want to try the Cryogenic engines pack:

http://forum.kerbalspaceprogram.com/threads/117766-1-0-Cryogenic-Engines-Pack-(high-Isp-chemical-rockets!)

[Galane]

The KR-2L has been severely nerfed. It's weaker and much heavier than the Mainsail. Just try to launch the Learstar. It has an on the pad TWR less than 1, unless the KR-2L is swapped out for a mainsail. Unless that's fixed, the big engine is pretty much useless in a first stage, and not so hot anywhere else, having less thrust and a lot more weight than a Mainsail.

The only reason to choose its mass would be if it's a whole lot more efficient at high altitude and in vacuum than a Mainsail.

*Makes a note to add a TI (Thrust Improved) KR-2L for ReStock...

If only Science (and rocket fuel chemists) could figure out how to overcome the many problems with fuels containing boron. 'Tis nasty stuff. Creates a whole lot of sticky solids which not only make a real filthy exhaust, they manage to glue up the nozzle throat to the point of sometimes choking it off. That causes the combustion chamber pressure to spike and *kaboom* if the fuel flow isn't cut in time. It's been a few decades since anyone has bothered to experiment with boron fuels. Someone needs to invent a coating so slick that boron soot can't stick to it, while also being able to withstand the temperature.

Chlorine-Fluorine fuels are *almost* practical. (One such was actually put into use on a pretty large scale, until the storage tanks it wasn't supposed to be able to corrode through began to fail.) Their main issue is handling and containment. Nevermind that some combinations can eat through a few feet of concrete and will react explosively with almost everything... Just need to push the boundaries of materials science. Unfortunately Dioxygen Difluoride (FOOF) will most likely never be useful for anything due to the process of making it requiring temperatures of 700C while the compound will react explosively with pretty much everything, even at liquid helium temperatures.

We have all read "Ignition!", right? If only Mono-Hydrazine was real...

[Rune]

I'm loving the gimbals. 8º on some of them, and configurable! When I get around to doing a crazy side-mounted stack (I think it'll be a Buran this time), that'll be a godsend.

Rune. STS replicas keep getting easier and easier.

[Wanderfound]

My go-to heavy lift vehicle for where I'm at in career mode uses a Mainsail core at around 1.1 TWR, with a pair of Kickbacks that bring it up to a more reasonable 1.3. I've been supplementing low-TWR main stages with SRBs and it's been working great. Haven't done any SRB-only first stages since the Flea/Hammer first/second launch, though, so I couldn't speak to that.

I've been using a setup with a core LV-T45 surrounded by four BACCs, with a small tank on top of each BACC feeding the core (with the small tanks designed to run dry just as the BACCs burn out). It works nicely for budget Munshots; there's just enough grunt to hoist a one-Kerbal LV-909 based Munlander plus transfer fuel.

[Redhaze]

So am I the only one who thinks the vacuum ISPs got utterly nerfed to oblivion?

I mean, I'm okay with atmospheric engines having had a bit of a nerf, it fits with the lower atmospheric drag so that, if you've got an aerodynamically sensible rocket, the same one will work in both .90 and 1.00. It's the part where all your non-nuclear transfer stages are nerfed that i can't stand. I mean, Where you had 1600m/s vacuum dV in .90, an identical setup in 1.00 would be lucky to 1200, a reduction of 25% for most engines. Essentially, the new so-called 'rebalance' made interplanetary/mun shots without nuclears pretty much useless.

TL,DR: Chemical vacuum engines got nerfed, LV-N is even more king now.

[Temeter]

So am I the only one who thinks the vacuum ISPs got utterly nerfed to oblivion?

I mean, I'm okay with atmospheric engines having had a bit of a nerf, it fits with the lower atmospheric drag so that, if you've got an aerodynamically sensible rocket, the same one will work in both .90 and 1.00. It's the part where all your non-nuclear transfer stages are nerfed that i can't stand. I mean, Where you had 1600m/s vacuum dV in .90, an identical setup in 1.00 would be lucky to 1200, a reduction of 25% for most engines. Essentially, the new so-called 'rebalance' made interplanetary/mun shots without nuclears pretty much useless.

TL,DR: Chemical vacuum engines got nerfed, LV-N is even more king now.

Actually, planetary tranfer vehicles are stil cheaper and easier than 0.9. See, you have 400dv less in Space, but your lander needed 1000dv less to bring said ship into space. Otherwise nuclear engines were always the prime choice for long range missions.

On the other hand, and as someone else said, we really could do with an engine in the 450 to 600isp range to bring some more flavor into the game.

[Redhaze]

Btw, did anybody noticed they Aerospike got stealthbuffed? 340 ISP in VAC now and 180 thrust at 1.5t weight. It's actually a quite good vacuum engine now too.

Actually, it's the opposite. It didn't get buffed, it's just the other engines which got nerfed harder.

Actually, planetary tranfer vehicles are stil cheaper and easier than 0.9. See, you have 400dv less in Space, but your lander needed 1000dv less to bring said ship into space.

Yea, except for the fact that that 1000m/s dV smaller launch stage is still as big as before, due to atmospheric engines having been nerfed as well. It also makes landing on non-atmospheric planets a lot harder as well.

[Cailean_556]

I'm curious what other people think about the solid boosters.

I feel like their Isp is way too low now to get any reasonable amount of delta-V out of a solid-fuel first stage, which used to be my go-to design in career mode

I've actually used SRBs a lot more in 1.0.2, same with the LV-T45. Though I guess I could now counter the inability to steer with the new Tail Fin (already in use on my Calliope IVc). Most of my LFRs are designed like the Falcon 9 (Calliope is the exception) - three tanks/engines side by side to get something into orbit and a smaller stage to keep it in orbit. I then scale that up as required based on payload and mission. I have found that SRBs seem to be a lot heaiver, but I haven't gone back into an older version to check the weights but 4 Kickbacks are heavier than 4 LFRBs which consist of 3 x FL-T800, a LV-T30 and a nose cone.

Having said that, 3 Kickbacks fired at the same time fall short of 2,500m/s in atmo...was trying to break the hypersonic barrier. Made Mach 7, but couldn't squeeze and extra +/-100m/s out of it.

[Redhaze]

It would be nice if somebody made new mass-optimal engine charts again, so that we could SEE, objectively, if the engines are balanced against eachother, but as i understand, the new math required to account for thrust changes isn't done yet.

[Temeter]

Actually, it's the opposite. It didn't get buffed, it's just the other engines which got nerfed harder.

Buffed between 1.0 and 1.0.1.

They had like 153 thrust.

Yea, except for the fact that that 1000m/s dV smaller launch stage is still as big as before, due to atmospheric engines having been nerfed as well. It also makes landing on non-atmospheric planets a lot harder as well.

Rockets are still a lot smaller than in 0.9, the nerf wasn't that hard.

[Kuu Lightwing]

The Shuttle SRBs were VERY heavy. The two SRBs constituted 69% of the shuttle's take-off weight. They also didn't have very good ISP, at 237 (sea level) to 269 (vacuum).

The Kickback's ISP is a bit low, but it might not be heavy ENOUGH.

Kickback is nowhere near Shuttle or SLS SRBs - its way too weak. SLS core cluster (our version of it is Mammoth) produces 7,440 kN of thrust, while single SLS SRB is 16,000 kN - more than 2x thrust. Kickback is only 650 kN compared to 3200 kN of Mammoth (AFAIR). To take the role of SLS or Shuttle SRBs it needs to produce about 10x more thrust than it does.