Wrong kind of love for the LV-1

[Rocket Farmer]

Taking it from 1.5kn to 4kn was a good start but it doesn't really change anything.

This rocket is in tough against the 24-88. Even with a buff for a mere 0.07 tonnes more you still get 7.5x thrust and 20% more fuel efficiency in the 24-88.

I actually do use it but only for sub 0.5 tonne craft which gave it a reasonable thrust of 3m/s already meaning the buff doesn't really change that.

What it needed was an efficiency bump. At 290 in space it is one of the lowest rockets available. Couple that with the "heavy micro tanks" (smallest 2 tanks don't conform to the 8/9 fuel/tank rstiolike the rest of the tanks) and your craft will actually be pretty inefficient with this rocket.

A low thrust (1.5kn) with a nice ISP (400ish) would have made it a solid competitor for the 24-88 from 0-1 tonnes (thrust traded off against efficiency). Instead we get a tiny bit of weight traded against efficiency and thrust.

Give the LV-1 some more love.

[Mephane]

Yeah, I agree, an improved efficiency would have helped that engine much more than stronger thrust.

[Tank Buddy]

Is the lv-1 getting a buff as well? That's great. From what you're saying, both the stack and radial version are going up to 4 kN. It could go along with the 48-7s and 24-88 and give the radial version less thrust. I don't think it should get and Isp buff, though. What could really use a buff are those lame radial engines with 120 kN.

[karolus10]

I see the other solution... make LV-1 use mono-propellant (same trust and ISP), it would make more sense to use couple of this for service module or additional engines for correction burns if you want to use one large RCS tank... also it had visual effects nearly same like RCS ports so it's only matter of changing their fuel.

IRL example:

Edited March 25, 2014 by karolus10

[merendel]

Er Op you might wana check your names theres no 24-88 engine. by the trust/weight references you make your probably talking about the 48-7s (tiny stack rockomax) While I agree the roco is still beter in most aplications it depends on what your trying to do. If your aiming for the smallest possible weight craft that mere .07 of weight can be a significant fractional weight increase. A craft that is a single solar pannel, an OKTO2, an oscar-B and an LV-1 weights .1536t, with a roco instead its .2236t. That accounts for around a 45% increase in mass. The extra ISP on the rocko wont offset the weight in that situation.

[Random Tank]

I agree with making it more efficient; with tweakables the 48-7S can just become one but more efficient... and shouldn't smaller engines be more efficient? (they get less efficient when they get bigger...) I think they should just make all of the Rockomax engines have higher thrust but less efficiency than the JKJSPC engines. In fact I'd love to see more rocket companies that are in competition with companies like Rockomax, making a choice between launch stage LFE's...

I don't think they should make the LV-1 use Monoprop, but add a new engine that uses monoprop (with obviously higher thrust, the Linear RCS port can already be a thruster)

Make the LV-1 have 3kN of thrust; 260s Atm ISP; 400s Vac ISP and weigh 0.05t (this means its great for small satellite, probes and tugs, but in bigger ships the LV-T45s and such will be better as they are much lighter vs thrust). The LV-1R can have 2.5kN but weighs 0.04t.

To make the Rockomax ones less amazing: Take their gimbal away (for what they should be doing, they shouldn't need it really); 20kN and 0.2t for the 48, 15kN and 0.15t for the 24, but efficiency should be the same as before.

But that's just my two sense....

[CalculusWarrior]

I see the other solution... make LV-1 use mono-propellant (same trust and ISP), it would make more sense to use couple of this for service module or additional engines for correction burns if you want to use one large RCS tank... also it had visual effects nearly same like RCS ports so it's only matter of changing their fuel.

https://lh3.googleusercontent.com/-s92vP2nhvxQ/UeHp2pG7h4I/AAAAAAAACSQ/oXLL3G8M2Cg/w900-h600-no/SharedRCS.png

IRL example:

http://nssphoenix.files.wordpress.com/2011/01/atv_service-module_large.jpg

That's a fantastic idea; it would definitely make the large RCS tank more useful.

[Giggleplex777]

I see the other solution... make LV-1 use mono-propellant (same trust and ISP), it would make more sense to use couple of this for service module or additional engines for correction burns if you want to use one large RCS tank... also it had visual effects nearly same like RCS ports so it's only matter of changing their fuel.

https://lh3.googleusercontent.com/-s92vP2nhvxQ/UeHp2pG7h4I/AAAAAAAACSQ/oXLL3G8M2Cg/w900-h600-no/SharedRCS.png

IRL example:

http://nssphoenix.files.wordpress.com/2011/01/atv_service-module_large.jpg

Umm, the ATV uses hypergolic bipropellants...

[Rocket Farmer]

Yes merendel I did get the name wrong. You are right sub .5 tonne is LV-1 territory but with the boost to the xenon engine even that's in danger. Now the LV-1 is only good for short range .5 tonne or less ships. Basically in this class it's a Duna (with its atmosphere) super light lander and not much else (the solar panels on a xenon won't do well on Duna.)

[karolus10]

Umm, the ATV uses hypergolic bipropellants...

RCS in ATV is hypergolic bipropellant as well, I always treated KSP mono-propellant as some imaginary variant of hypergolic fuel... unless they use cannned air.

(haha)

Anyway, I would like to see couple hypergolic engines sharing same fuel like RCS, small ones like LV-1 and bit bigger half meter class engine (bigger than Rockomax 48-7S) that could be used for service modules or orbital thursters in space-planes like in shuttle OMS, it would be very convenient for smaller crafts.

Also I agree that linear RCS port could look more like... thruster.

Edited March 26, 2014 by karolus10

[NecroBones]

RCS in ATV is hypergolic bipropellant as well, I always treated KSP mono-propellant as some imaginary variant of hypergolic fuel... unless they use cannned air.

I think that's the general implication in the game, so I would agree. It's like some sort of hypothetical, hypergolic monopropellant, as if that made sense.

[lincourtl]

I see the other solution... make LV-1 use mono-propellant (same trust and ISP), it would make more sense to use couple of this for service module or additional engines for correction burns if you want to use one large RCS tank... also it had visual effects nearly same like RCS ports so it's only matter of changing their fuel.

https://lh3.googleusercontent.com/-s92vP2nhvxQ/UeHp2pG7h4I/AAAAAAAACSQ/oXLL3G8M2Cg/w900-h600-no/SharedRCS.png

IRL example:

http://nssphoenix.files.wordpress.com/2011/01/atv_service-module_large.jpg

Oh, I definitely want small monoprop engines in stock. So useful. It'd be nice to have a couple of more monoprop tanks as well.

[Joonatan1998]

So instead of nerfing the 48-7S, They buffed all the other tiny engines?

[wasmic]

I think that's the general implication in the game, so I would agree. It's like some sort of hypothetical, hypergolic monopropellant, as if that made sense.

Hypergolic monopropellants do exist, they just have ****ty performance compared to bipropellants.

[Red Iron Crown]

Hypergolic monopropellants do exist, they just have ****ty performance compared to bipropellants.

I don't think this is correct. Hypergolic means no ignition source is necessary, the fuel spontaneous ignites when the components are combined. A monopropellant that needs no ignition wouldn't be storable.

There does seem to be a "missing" engine, a 0.625m chemical rocket with high vacuum Isp. Whether it appears via buffs to existing engines or a new part, it is a gap I think should be filled.

[Thiel]

I've always asumed RCS ran on a catalytic monopropellant like Hydrazine

[lincourtl]

I don't think this is correct. Hypergolic means no ignition source is necessary, the fuel spontaneous ignites when the components are combined. A monopropellant that needs no ignition wouldn't be storable.

No, that's not quite true. Hydrazine is a hypergolic monopropellant. It requires no ignition source, but it does require a catalyst. For a rocket, that often means a catalyst bed in the decomposition chamber -- a packed bed of solid catalyst particles.

In this diagram, the gas chamber holds inert gas used to pressurize the monopropellant tank, and force the monopropellant into the decomposition chamber.

[Red Iron Crown]

No, that's not quite true. Hydrazine is a hypergolic monopropellant. It requires no ignition source, but it does require a catalyst. For a rocket, that often means a catalyst bed in the decomposition chamber -- a packed bed of solid catalyst particles.

In this diagram, the gas chamber holds inert gas used to pressurize the monopropellant tank, and force the monopropellant into the decomposition chamber.

That doesn't mesh with the definition of hypergolic I've seen.

Edit: Wikipedia seems to agree with me: http://en.wikipedia.org/wiki/Hypergolic

Edited March 26, 2014 by Red Iron Crown

[lajoswinkler]

If something is hypergolic, it reacts with something else upon mixing, period.

[karolus10]

I guess that monopropellant can be considered as equivalent of IRL hypergolic fuels used in RCS, as long as Fuel total density and ISP will be similar to real numbers (I didn't say that fuel densities are truly balanced now) as it's simplified because of lack of different fuel types and game simplification.

Same it could go for for liquid fuel/oxidizer, more fuel types aren't necessary if it's density/efficiency is somewhere between Lox/Kerosene and Lox/LH2.

Also please remember that this is topic about LV-1 (AKA "ant") engine ;-).

[lincourtl]

That doesn't mesh with the definition of hypergolic I've seen.

Edit: Wikipedia seems to agree with me: http://en.wikipedia.org/wiki/Hypergolic

Maybe we're getting hung up on the semantics of 'ignition source'? I think of an ignition source as a spark, or flame, or heater coil. And from the Wiki article you cite:

"Hypergolic rockets are usually simple and reliable because they need no ignition system."

Hypergolic compounds spontaneously ignite when combined with a catalyst. It's chemical ignition. There's no need for any external ignition source. That's where I'm coming from.

[Nuke]

way i see it, some of these smaller probe engines should be monoprop (hydrazine) engines, because thats what we used on long range probes before we went to ion propulsion. the isp on these engines is already in the neighborhood of what you would get from a pressure fed hydrazine thruster. so why not make some of the lower performance probe engines into monoprop engines.

[lajoswinkler]

Maybe we're getting hung up on the semantics of 'ignition source'? I think of an ignition source as a spark, or flame, or heater coil. And from the Wiki article you cite:

Hypergolic compounds spontaneously ignite when combined with a catalyst. It's chemical ignition. There's no need for any external ignition source. That's where I'm coming from.

But hypergolic stuff needs to react with something in order to make something with that thing. If ABC reacts with a catalyst D, the intermediate is ABCD, and yields for example AB+C and catalyst D. Catalysts aren't spent, they just lower the energy needed for the reaction.

In essence, ABC decomposes at lower energy. "Hypergolic" means there is a reaction between two substances yielding new compounds made of those substances, all of that without more energy than it already exists in the reactants at the desired temperature and pressure conditions.

From a chemical standpoint, we can't call spontaneous decomposition "hypergolic". For instance, if you throw a spoonful of manganese dioxide into a glass of 30% hydrogen peroxide, it will almost explode because of the heat it releases, turning the water into steam. But it's not hypergolic. Manganese dioxide is still there.

Hypergolic reaction is between fuming nitric acid and certain organic compounds, between fluorine and hydrogen, chlorine trifluoride and gasoline, etc. When they react, reactants are spent in a furious reaction.