Do the "Kickback" SRBs burn for less time than they used to?

[THX1138]

Do the "Kickback" SRBs burn for less time than they used to?

[zekes]

This is a thing - they burn out much faster than I'm used to. Don't have the game open right now but I bet it's on the KSP wiki.

[Leszek]

All of the engines are less efficient then they used to be. That means that they will either burn through the fuel faster, or they will have less thrust, or both.

[Claw]

The RT-10 definitely had it's solid fuel load reduced. I'm not sure about the BACC and SLS SRB.

The flea (RT-5) obviously didn't exist, and I'm not really sure if it needs to... I think I would have rather had a smaller (size 0) SRB myself.

Cheers,

~Claw

[THX1138]

The RT-10 definitely had it's solid fuel load reduced. I'm not sure about the BACC and SLS SRB.

The flea (RT-5) obviously didn't exist, and I'm not really sure if it needs to... I think I would have rather had a smaller (size 0) SRB myself.

Cheers,

~Claw

Smaller?? I need a larger one so I don't have to use so many Kickbacks! Won't someone think of the part counts!

[panzer1b]

Not sure what a kickback is, but all the SRBs appear to have lost both fuel capacity AND ISP. The RT-10, BACC, and the massive srb thing are all worse now, and the RT-5 is useless for all intents and purposes unless you are making kinetic missiles to shoot at stuff (works wonders for that purpose).

Then again, it takes less dV to get into orbit, and id assume it was like the engine ISP changes made to balance the rockets and not make it single SRB to orbit game.

[Gaarst]

I think Kickback always had 2500 solid fuel and 650 kN thrust but its burn time and Isp have definitely been reduced.

Burn time is now ~49s in atmosphere (according to KER) but was 65s (according to the not-updated wiki)

[DoToH]

Same fuel quantity. Less ISP now. Burns fuel faster.

Note it's 1,5 tons heavier and 50% more expensive.

[Wanderfound]

The nerf was needed; ÃŽâ€V to orbit is down to roughly what it was in FAR, and with that I could easily launch interplanetary probes on nothing but a single large SRB. Made it rather too easy.

[Claw]

Yeah, I used to rely a lot more on SRBs than I do now. They don't feel like they have much of a use anymore except TWR off the pad. I used to build multi-stage solid rocket stacks for cheap probe and satellite contracts. They aren't any where near as useful for that any more.

[Kuu Lightwing]

I think they should change the model of it, as well. It looks like SLS booster, but has 10x less thrust than it should.

[Technical Ben]

The RT-10 definitely had it's solid fuel load reduced. I'm not sure about the BACC and SLS SRB.

The flea (RT-5) obviously didn't exist, and I'm not really sure if it needs to... I think I would have rather had a smaller (size 0) SRB myself.

Cheers,

~Claw

True. While it would have looked funny to some extent it would of also have fitted KSP style more.

It would be a tiny rocket for a larger pod, and the kerbals would look kerbal for it, not just "smaller".

[Claw]

Smaller?? I need a larger one so I don't have to use so many Kickbacks! Won't someone think of the part counts!

Perhaps I was misleading. Rather than bringing dow the SRBs as much as they are, I would have preferred a bit less nerf and, instead, had some smaller boosters for the early game...instead of a half sized RT-10 that burns for something like 7 seconds.

[basic.syntax]

The RT-5 'Flea' was designed to be "MyFirstRocket" in career, I can't find the post atm, but remember something about the RT-10 was thought too overpowered for a first launch.

I think it was designed to look good under the 1-Kerbal capsule, it had to be size 1.

[purpletarget]

Part of the issue with the perception is also the change to the way fuel flow and ISP work.

As of 1.0, the fuel flow rate is constant, and the ISP variance with altitude results in higher thrust as the engine climbs. So if the SRB is set (via tweakable thurst limiter and propellant) to run for 30 seconds, it will run for 30 seconds. Off the pad it will have a lower thrust, and that will increase as the SRB climbs to lower pressures, and higher ISP values.

In 0.90 and prior, the thrust was fixed, and the Fuel Flow would be modified by the ISP. So, if the SRB was clamped on the ground, and forced to burn at the lower ISP, it might run for 25 seconds, where-as if it was allowed to climb, it would start using less fuel per second as it went up, so the total run time could be 35 or 45 seconds depending on where it was activated, and how quickly it climbed to near peak ISP values. The higher it went, the higher the ISP, lower fuel flow, longer burn time.