rhino engines, what are they good for?

[Sweetnsaltyish]

I've been looking thru all of the engines that I use, and came across the rhino engine.

I know it could be used as a first stage engine, but I has its highest efficiency in a vacuum, and not at sea lvl.

what kind of upper stage craft would need that kind of power?

[Gargamel]

7 minutes ago, Sweetnsaltyish said:

what kind of upper stage craft would need that kind of power?

Really, Really big ones apparently. 

[Sweetnsaltyish]

9 minutes ago, Gargamel said:

Really, Really big ones apparently. 

wiser words have never been spoken . . .

 

[Atkara]

11 hours ago, Sweetnsaltyish said:

I know it could be used as a first stage engine, but I has its highest efficiency in a vacuum, and not at sea lvl.

Like you said, it has the highest efficiency in a vacuum, not at sea level. However, by the time the launch vehicle reaches 10km altitude, the Rhino is already operating at ~85-90% efficiency. So you add side-boosters, better suited for atmospheric operation and when it gets to 10-15km, you stage and let it go. Like this for example:

And if you are taking it to space anyway, why not install proper guidance & RCS and use it as a transfer vehicle?

Spoiler

That's obviously one way of using it. The rest, I think they fall into the category Gargamel described  

[StrandedonEarth]

Tankers and supertankers, when you don't want to have to work out a ten-minute burn. I use them all the time on those

[klesh]

I can honestly say I have never used them, not once.  The permanent 3.75m tankbutt kills it for me. 

[Blasty McBlastblast]

After being dried and ground to a fine consistency, the Rhino engine bell can be used as an aphrodisiac to boost struggling rockets...

[theJesuit]

7 hours ago, klesh said:

I can honestly say I have never used them, not once.  The permanent 3.75m tankbutt kills it for me. 

ReStock for the win then!

[Ratwerke_Actual]

I got into Rhino fever back in 1.0.5.

Played stock, before DLC.

The Rhino made a lot of sense for large transfer and insertion stages, like Eve landers and Jool missions. Even used it in tandem with nukes for some asteroid missions for those maneuvers where a fast kick was needed, vs. a slow nuke burn.

[herbal space program]

I can't honestly say I've ever used one either, since at 3.75 m they take up rather a lot of cross-sectional area for that amount of thrust, and for general orbital maneuvering I'm more inclined to live with the low-TWR Nervs. But looking over the engine stats it appears that nothing else with that amount of thrust and TWR comes close to its vacuum ISP value, so I guess stuff like a really big Tylo lander would be a niche where it would really shine. It might also be really good for the final stage of a large Eve lifter, where you need to circularize relatively quickly to maintain altitude. In fact, I might just give it a whirl for what I'm doing on the big Eve thread....

Edited March 8, 2019 by herbal space program

[ZooNamedGames]

Rhino is great for massive stages. Can't count how many behemoths I put into orbit using the Rhino. It isn't practical for anything small but the bigger you go, the nicer it works.

[ExtremeSquared]

Two ways to send a gigantic mine/base off to Jool. Ten minute burn with nuke cluster from a 200km orbit, or 90 second burn with a rhino from a 75km orbit. Both valid. Similar cost.

[herbal space program]

14 minutes ago, ExtremeSquared said:

Two ways to send a gigantic mine/base off to Jool. Ten minute burn with nuke cluster from a 200km orbit, or 90 second burn with a rhino from a 75km orbit. Both valid. Similar cost.

90 seconds is an acceptable length for an efficient single ejection burn, but if you take 10 whole minutes from a 200km parking orbit, you are wasting quite a bit of dV.  It's much better to go to a 70 km circular orbit and do multiple shorter kicks at its PE, until you are nearly on an escape trajectory, before doing the final burn. I guess if you're going straight to Jool that might still take a while, but I never actually do that because it takes too much dV that way.

[ExtremeSquared]

Definitely true. The 200km orbit is a side effect of an ascent profile capable of achieving reliable orbit in a behemoth with an insertion/transfer stage TWR below 0.1.

Edited March 8, 2019 by ExtremeSquared

[klesh]

4 hours ago, theJesuit said:

ReStock for the win then!

 

You know it, baby!  I'm blown away by how good it is.

[farmerben]

Inspired by Herbal.  

 

Packing 1 Rhino, 4 poodles, large ISRU with 4 drills and extendable radiators, 2 large fuel cell arrays so the processor can run non stop....  220 tons 1.72 TWR, 4524 m/s dV.

It can land on Tylo, mine and return to orbit.  Probably unsuitable for multiple landings on Tylo,  but it could refill easily on the smaller moons.  I had about 1/4 fuel left.

 

The nice thing about stuctural pylons is that they can be fired one at a time by right click menu.

 

I

 

I had about 1.5 of these full.  They could push significant payloads to the other moons.  Remember, It doesn't count as debris if its an active comsat

Edited March 9, 2019 by farmerben

[Xavven]

I used a Rhino engine as my main transfer stage for a Moho land and return mission. When you need both lots of dV and high thrust, as Moho orbital insertion demands, it's a great choice on big stages.

[Grogs]

I've never used one. I always use engine plate + multiple vectors instead. Two vectors provide the same vacuum thrust / much better sea level thrust at 8.075 tons vs. 9 for the Rhino. The better ISP of the Rhino probably wins out for super-heavy ships, but for one of those I'll likely have 3-9 vectors. You don't have that flexibility to choose the thrust you want with the single Rhino.

[Jaime]

I use them for the 2nd stage of my large segments (eg. Duna assent module or HUGE xenon propulsion modules.) It gives a good kick to orbit.

[Aegolius13]

It's passable as a sustainer or even core stage for really, really big rockets, but I feel like you kind of have to build around the Rhino concept to make this worthwhile.

I've used it on some stupidly large mining rigs. You can save a lot of part count vs. using a ton of nukes, and the delta-v loss doesn't matter much on low-gravity bodies.  However, the Wolfhound probably eats into this use-case now. 

It's also decent for redirecting large asteroids.

[GRS]

Used it as Centurion rocket family's Transfer stage core...

[Ratwerke_Actual]

An older twin-Rhino tug I used for moving asteroids during station construction.

[Reinhart Mk.1]

On 3/8/2019 at 6:36 AM, Blasty McBlastblast said:

After being dried and ground to a fine consistency, the Rhino engine bell can be used as an aphrodisiac to boost struggling rockets...

genuinely laughed, thank you sir

[NorthernDevo]

I LOVE the Rhino as a transfer stage. 

Part of my gameplay is to build the most efficient rockets possible, but looks are an important consideration.  I like using the thing as a transfer stage to the Mun with a 3-Kerb orbiter/lander stack, it just looks so cool when it separates and burns. 

I can't show a pic; I'm doing a new career and haven't reached that stage yet, but I do use it a lot, and quite enjoy it.

 

[Freshmeat]

I used it as a lifting engine for an intermediate class booster, in tandem with 6-8 Kickbacks. A lot cheaper than Mammoth, bigger payload than Twin Boar + Kickbacks. Also used it a few times for sustainer on really big builds, but I can usually downscale to a lighter or cheaper engine. This was before MH, so there might be better alternatives now.