Ant Engines

[BrotatoSalad]

Let's just take some time to think about the ant engine. Specifically, why everyone hates them so much. They're actually very handy for small landers. They're often used as an example of a useless engine, but please give them some love for their high twr and cheerful attitude.

[Bill Phil]

I don't use them much, but that's because it's such an annoying engine sound. I also don't use miniature probes that often.

Otherwise they're pretty good.

[Solivagant]

I used them mostly for small "marker" probes for keeping on track with rover driving. They slow down pretty well, but I never found many other uses for them. I actually like them because they blend in well compared to the gaudy yellow/black of a lot of the other engines.

[magnemoe]

The problem with the ants are poor ISP, its so poor the ant looses over the 48-7S if you use more than 2 oscar tanks.

[prophet_01]

I use them for probes to eve and duna. I play with DRE, FAR and remote tech. That leads to some difficulties since I need a heatshield, an antenna and have to take care of my COG/COL. I like the flexibilty of small radial engines cause the front and the back are occupied (heatshield and satelite dish). I took me hours, but now I have a nice design with an integrated lander and it's small enough to fit in my mk2 shuttle

The other small radial engine is orange... and although that's not particulary bad I don't like it's look that much. The ant looks nice and is enclosed (although the sound is pretty anoying). I either do pretty oversized manned missions or probe missions that are as tiny as possible. The ant is perfect for that

[Aragosnat]

Yeah. They are useful for using on small probes. But, most of the time by the time I need small probes I can get bigger more useful ones or have access to the other tiny engine parts that make such a part not look as good and more costly then the Rockomax 48-7s. Now if we had square or rectangle fuel tanks and decouplers. Then the ant might be perfect. Also it might be alright for a Mün or Minmus Escape craft with a rover seat attached or for repositioning light Sattilites that have fuel and a docking port for just in case you want to move it around when it runs out of fuel.

[prophet_01]

My preference is to do small one way probe missions with only the smalleat science equipment and a bigger manned missions. In my career saves the reduced amount of science for transmissions usually makes me include the more valuable (and heavier) equipment into the manned missions. The manned missions usually include a lab, a small fuel depo and a reusable lander to max out the science. I know I don't need to do that to complete the tech tree, but the perfectionist inside of me screams every time I lose science due to transmissions :/ can't help it. So if I use probes they will be tiny.

I also like to prepare more than one mission with a single launch (usually a shuttle). That's obviously easyer with a small probe. And again, I like the ants for that btw I don't like part cliping as it tends to look weired. If I remember corectly the small orange radial engine caused cliping issues with the cargo bays sometimes (only a little bit though)

[rodion]

it was always an okay part in my opinion, until the 24-77 arrived and blew it out of the water in every possible way.

[Frank_G]

I havent used them frequently since the fine monopropellant engine came out. Having that extra push of fuel stored in the capsule makes all the difference when it comes to small and efficient landers. But i still consider and use them on probes and satellites.

[lukeoftheaura]

I like radial ant engines

[cantab]

They're OK, the problem is the 48-7S has better efficiency and much higher thrust, though said thrust can be too high for very light craft. Meanwhile the RCS ports are massless now if you want a light low-thrust engine.

That said, if I do another multi-flyby probe I'll use the ant, its precision burn capabilities are unmatched.

The radial ants may fair a bit better, since the 24-77 is not so good an engine as the 48-7S.

[SRV Ron]

Ant Engines are excellent for small probes;

Landing gear not required;

[Red Iron Crown]

The part I don't get with ant engines (and ions, too) is why no fuel bar shows in the staging list for them.

[sal_vager]

HarvesteR mentioned why once, ages ago, I think it was because they use fuel slow enough that they don't need the bar visible, you can check the resource tab and it helps declutter the screen

Edited November 28, 2014 by sal_vager
Missed the c from once.

[Red Iron Crown]

I dunno sal_vager, an ant engine is usually paired with tiny fuel tanks so the bar would probably work about the same as with larger tanks and fuel.

[Crown]

They're OK, the problem is the 48-7S has better efficiency and much higher thrust, though said thrust can be too high for very light craft. [...]

I discovered recently that the 48-7S is more efficient, has higher thrust and is cheaper than the LV-1 "Ant" . I don't know where they are located in the tech tree but from now on I want to build my probes with 48-7S instead of the LV-1.

I never thought of using RCS thrusters as a main engine, Vernor and O-10 are very new to me and I never really found a field for them to use in. They have the same ISP as the Ant (290sec) so maybe I can figure out something.

Edited November 28, 2014 by Crown
typo

[JayKay]

I use the radial ant engine to balance the mass of a side-mounted SCANsat scanner by mounting it on the opposite side of the body from the scanner (they both have a mass of .03.) I tweak the thing down to no thrust so it doesn't fire by accident and end up in the "this will not end well" thread. But more on topic, I only used them once or twice as ascent engines on small landers if there was a decoupler mounted below the lander for payload or something.

[lajoswinkler]

I like them. What I don't like about them is the lack of the fuel bar and their "flame" which looks like someone is puking cotton balls in space, but none of the engines in whole KSP shows what exhaust looks like. Not even with remote accuracy.

(simulation of vacuum)

(test in very low pressure)

A simple static plume would be better than cotton balls.

Edited November 28, 2014 by lajoswinkler

[GloriousWater]

I find the ant engine really useful, since it can give some 3km/s delta-v from just 30 liquid fuel, with less mass than a 48-7S. The low ISP isn't that important when you can make a probe with a mass of 600kg, as saving mass tends to give better results than having a high ISP. (example: using multiple 48-7S on cubic struts instead of a nuke as a transfer stage gives higher delta-v)

As for the sound and exhaust effects, I actually like them a bit

[SRV Ron]

I discovered recently that the 48-7S http://wiki.kerbalspaceprogram.com/w/images/thumb/9/9a/Rockomax_48-7S.png/60px-Rockomax_48-7S.png is more efficient, has higher thrust and is cheaper than the LV-1 "Ant" http://wiki.kerbalspaceprogram.com/w/images/thumb/4/47/LV-1_Liquid_Fuel_Engine_HD.png/60px-LV-1_Liquid_Fuel_Engine_HD.png. I don't know where they are located in the tech tree but from now on I want to build my probes with 48-7S instead of the LV-1.

I never thought of using RCS thrusters as a main engine, Vernor and O-10 are very new to me and I never really found a field for them to use in. They have the same ISP as the Ant (290sec) so maybe I can figure out something.

Burning fuel and oxygen is far more efficient mass wise then using monoprop. Test it for yourself and see how far you can get with each types of fuel.

[Starman4308]

Burning fuel and oxygen is far more efficient mass wise then using monoprop. Test it for yourself and see how far you can get with each types of fuel.

At the very low-mass level, monopropellant is actually better. The O-10 monopropellant engine and the LV-1s both have 290s Isp. The O-10 is physics-less, while the LV-1 has a mass of 0.03t. Additionally, the FL-R10 monopropellant tank has a 5/1 mass ratio, while the ROUND-8 tank has 4.67 mass ratio. The first LF/O tank with a better mass ratio is the FL-T100, with a mass ratio of 9.33/1.

A single FL-R10 and a Stayputnik core will give you 3128 m/s dV for 0.3t of mass. Two ROUND-8 tanks with an LV-1 and a Stayputnik give you 2689 m/s dV for 0.36t of mass. It's only when you get to the FL-T100 that the story goes the other way: two FL-R10s net you 3700 m/s of dV for 0.55t, while a single FL-T100 nets you 4328 m/s of dV for 0.64t. If one were to extrapolate the mass ratio of the FL-R10, a theoretical 0.64t probe with the O-10 would get 3808 m/s for the same 0.64t.

[Xavven]

At the very low-mass level, monopropellant is actually better. The O-10 monopropellant engine and the LV-1s both have 290s Isp. The O-10 is physics-less, while the LV-1 has a mass of 0.03t. Additionally, the FL-R10 monopropellant tank has a 5/1 mass ratio, while the ROUND-8 tank has 4.67 mass ratio. The first LF/O tank with a better mass ratio is the FL-T100, with a mass ratio of 9.33/1.

A single FL-R10 and a Stayputnik core will give you 3128 m/s dV for 0.3t of mass. Two ROUND-8 tanks with an LV-1 and a Stayputnik give you 2689 m/s dV for 0.36t of mass. It's only when you get to the FL-T100 that the story goes the other way: two FL-R10s net you 3700 m/s of dV for 0.55t, while a single FL-T100 nets you 4328 m/s of dV for 0.64t. If one were to extrapolate the mass ratio of the FL-R10, a theoretical 0.64t probe with the O-10 would get 3808 m/s for the same 0.64t.

I agree with Starman. I have a Mun probe based on the O-10 engine that's designed to hop around looking at scenery, then return to Mun orbit for a refuel before going back to the surface. I experimented with changing the design to use the ant engine or the 48-7S, and found that the added weight of having to carry a separate tank for my monopropellant, which is necessary for docking maneuvering, ultimately causes the lander to be heavier for the same delta-v, despite the better ISP from the bipropellant engine!

I was quite surprised at that result. Up until 2 weeks ago, I had completely dismissed the O-10.

[Boris_T_Roach]

I like 'em

Mind you I only use them on small craft to adjust AP/PE by a small amount after the craft has been released into orbit by a larger ship

Although I've now taken to ions for the job

[SkyRender]

The Ant is my go-to engine for tiny space probes. Don't know why anyone would hate them, they're perfect for those things.

[moogoob]

I use them in situations where it's important to have an engine of some sort, but not necessarily a good engine. Where a low launchpad weight is more important than a probe's delta-v.

In all other probe situations I'll use the little orange Rockomax.