Why won't LV-909 "Terrier" engine fire?

[JackBush]

I copied a Scott Manley ship and he used it as the final power source for moving the pod around in orbit, etc. All others beneath it fire and uncouple perfectly. And I just tried it as the first power source for another ship and it did nothing but make a noise on the launch pad. What's the trick?

Edited September 21, 2015 by JackBush

[The_Rocketeer]

It has fuel, right?

[Dfthu]

Pics would help

[Harry Rhodan]

I copied a Scott Manley ship

You know that he made countless videos and ships over the last few years?

[ForScience6686]

The problem is it does not have enough power, especially in atmosphere. It is great once in space though. You'll need something bigger on your first stage.

[The_Rocketeer]

The problem is it does not have enough power, especially in atmosphere. It is great once in space though. You'll need something bigger on your first stage.

Yes, if it's activating correctly (which isn't clear from your post) chances are it's too underpowered. Engine ISP was overhauled not long ago so rockets have much less thrust at the surface. Could be SM's video dates from before the update (very probable).

[JackBush]

Yes, it has an FL-T200 fuel tank above it. I have a screenshot but am not allowed to make attachments for some reason. And to insert it requires an URL. It's sitting on my desktop which, to my knowledge, is not or has no URL. Any ideas?

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[Gaarst]

You must upolad your screenshots on the Internet with Imgur or others.

[jaredkzr]

Yes, it has an FL-T200 fuel tank above it. I have a screenshot but am not allowed to make attachments for some reason. And to insert it requires an URL. It's sitting on my desktop which, to my knowledge, is not or has no URL. Any ideas?

Upload your picture to an image hosting website such as www.imgur.com to allow you to paste a URL here for us all to see it.

[JackBush]

Upload your picture to an image hosting website such as www.imgur.com to allow you to paste a URL here for us all to see it.

Okay, here it is. http://imgur.com/a/bFMok

[The_Rocketeer]

If that has a Terrier on the bottom, it's far too heavy for it. Your TWR is way too low.

[xebx]

The top part is : LV909 Terrier + FLT200 Tank + science mat + Pod ? it should be ok, check your staging and if thrust limiter is 100% (in VAB right clic on engine), tanks are full and unlocked ?

[ForScience6686]

I can't tell what engine you as using on your lift stage, but I would use the srbs before firing the engine. Even then I doubt you'll have enough thrust, you need to save the terrier until you get to space. I think you only have 1/3 the thrust at sea level with that engine, so no real power except to blow leaves around.

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Also, it looks like you are dumping the science Jr before reentry, you're losing a bit of science by not bringing it back.

[xebx]

(reread the 1st message) Ah yes if he's using LV909 Terrier on launchpad, it won't move, it's a vacuum engine thrust is very low At Sea Level.

[cantab]

There's nothing obviously wrong there, but do note how your staging works - you'll drop the first stage with a tap on the spacebar, then have to wait a couple of seconds before pressing the spacebar *again* to light the 909 engine.

By the time you ignite that 909 you should easily be high enough to get decent thrust out of it. I assume the first stage is a Swivel, but even if that's a 909 it will still be lifted up by the boosters.

[Signo]

I think you are simply out of electric power. I can not see any battery or solar panel there.

[Snark]

It's not working because the LV-909 is only good for vacuum and has almost no power on the launchpad. Don't use it there.

It didn't use to be that way-- before 1.0 it would have worked just fine there, which I expect explains the video you saw.

One big change with 1.0 is that several engines (including the LV-909) have been re-balanced as vacuum engines. That is, they have really crappy Isp in atmosphere. This is coupled with another 1.0 change, which is that the effect of lowered-Isp-in-atmosphere is to reduce thrust, rather than increase fuel consumption.

The upshot of this is that the LV-909 gives pitiful thrust in atmosphere (something like 12 kN), while still gobbling plenty of fuel.

[JackBush]

The top part is : LV909 Terrier + FLT200 Tank + science mat + Pod ? it should be ok, check your staging and if thrust limiter is 100% (in VAB right clic on engine), tanks are full and unlocked ?

Yes, you're right. I will check my staging, although I'm sure it's correct. (Can you tell from the stages as listed in the screenshot?). The thrust for the lower engines is set at between 1/3 and 1/2 as suggested by Scott. But I will check it for the Terrier. Tanks are full and I assume the tank above the Terrier is full because it's right off the VAB shelf. But I will check that, too. And finally: I don't know what you mean when you ask if the tanks are "unlocked". Can you please explain? it's a single FLT200 tank above the Terrier as you noted.

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I will check the staging, cantab and you might be right about me having to wait a couple of seconds before tapping the spacebar to ignite the 909.

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The lift stage is powered by one of the LT engines and the Terrier is for the final stage. What do you mean by "srbs"?

[Signo]

SRBs are the solid boosters.

Did you check your power supply? I keep on thinking you are completely out of power and that's your issue.

[JackBush]

SRBs are the solid boosters.

Did you check your power supply? I keep on thinking you are completely out of power and that's your issue.

Maybe you're right. What's the best solution?

[klesh]

What's the best solution?

I was thinking a power issue too. In the upper right of the screen is a resource button. It lets you see the fuel, oxidizer and electricity your ship has. I bet you will see the electricity has run out by the time you flew up to orbit. You lose electric charge when you turn your ship. When your engine wouldnt fire, could you still spin the ship around or did it feel "dead?"

Either slap a pair of batteries on the command pod up top, or 3 of the flat, single piece solar panels up there. 3 allows at least 1 to face the Sun at all times. Using just batteries will give you extra juice, but once its used, without a solar panel (or an RTG later on) you wont be able to generate more electricity.

[cantab]

On a Kerballed ship power is not required for control. Staging, throttling engines, and steering will all work with no electricity whatsoever. Reaction wheels that rotate your craft won't work but steering by engine gimbal, RCS, control surfaces, or most wheels will all still operate.

[JackBush]

then have to wait a couple of seconds before pressing the spacebar *again* to light the 909 engine.

That's the answer. Thanks to everyone for your input.