Engine for Super-Heavy

[TitiKSP]

I was making Starship Super-Heavy then I think would would be the best engine?

[steuben]

Define super heavy.

[Clamp-o-Tron]

Vector. Excellent efficiency, superior TWR, very good gimbal range, good for clustering, and somewhat resembles the real Raptor.

[Zhetaan]

1 hour ago, Clamp-o-Tron said:

Vector. Excellent efficiency, superior TWR, very good gimbal range, good for clustering, and somewhat resembles the real Raptor.

There's also the Mammoth, which is actually four Vectors in a trenchcoat.

[Clamp-o-Tron]

15 minutes ago, Zhetaan said:

There's also the Mammoth, which is actually four Vectors in a trenchcoat.

Not great for clustering though.

[Spricigo]

It depends...

What are you going for?

How much payload you want it to care? How much deltaV left in orbit for the Starship? (with or without orbital refueling?) Where the Startship is meant to go? It need to looks like the SS+SH or just work in a similar way? Is a parachute landing fine or a powered landing is required?  It will land at KSC or just within acceptable range? Career or Science/Sandbox?

Some of those option ma  narrow it to a few engines options (e.g : Vector, Twin Boar, Kodiak, Mammoth for the booster; Rhino, Dart, Wolfhound, Nerv for the upper stage) while other may allow for crazy stuff like SRB/Jet combos.

 

[Entropian]

The Ant. 

 

[king of nowhere]

3 hours ago, TitiKSP said:

I was making Starship Super-Heavy then I think would would be the best engine?

specify a weight. there was a time i considered 100 tons to be super heavy. now the heaviest i launched was over 1000 tons, and some people are launching well above that

[Spricigo]

5 minutes ago, king of nowhere said:

now the heaviest i launched was over 1000 tons, and some people are launching well above that

Sure. While some players do things like this:

I barely find a reason to use this:

https://kerbalx.com/Spricigo/Krakatoa

IMHO at the point in career it's viable to launch craft of that size*, re-usability is probably a moot point already and concerns with practicality and efficiency can easily be throw out the window.  For those there is little incentive to go for anything but Mammoths with the odd vector/twinboar/clydescale  finding use here and there. And since we don't want orbital meneuver to take weeks, not likely to use something smaller than the rhino in space.

However, experience tells that is probably not the case for the OP.  More likely looking for a viable alternative with more limited options (Mainsail? Skipper? Cluster of Reliants?) Personally, I want to see if that is what we should look for before give him the false impression that only the later prtsof the tech tree have useful stuff.

 

*I mean, not even a sounding rocket by@Whackjob standards. Just what we mortals can do.

[Geonovast]

Guys, I'm pretty sure the OP is talking about making a SpaceX Starship/Superheavy build, not just a "super heavy" launch vehicle.

[king of nowhere]

1 hour ago, Spricigo said:

IMHO at the point in career it's viable to launch craft of that size*, re-usability is probably a moot point already and concerns with practicality and efficiency can easily be throw out the window.  For those there is little incentive to go for anything but Mammoths with the odd vector/twinboar/clydescale  finding use here and there. And since we don't want orbital meneuver to take weeks, not likely to use something smaller than the rhino in space.

 

yes, but just because one can build a bigger craft, it doesn't mean one wants to do it.

personally, i stopped advancing my career and went to make challenges instead specifically because in career i could do anything with a bigger craft, and there was no challenge in that

1 hour ago, Geonovast said:

Guys, I'm pretty sure the OP is talking about making a SpaceX Starship/Superheavy build, not just a "super heavy" launch vehicle.

yes, but even that leaves a lot of wiggle room, as kerbal models aren't really up to scale with human ones. so, i can imagine a starship replica anywhere between the 100 and 10000 tons range.

[TitiKSP]

19 hours ago, steuben said:

Define super heavy.

Starship Super-Heavy.

 

[paul_c]

Its like anything else, you build a structure/payload/instruments etc portion, you size the fuel tanks according to the mission profile, then you calculate (or guesstimate) which engine/engines will produce the relevant TWR for that (stage of the) mission. Of course, its an iterative process, because the engine(s) will have a weight, which affects the amount of fuel needed, which affects the fuel tankage, which affects the overall weight.

In KSP, I've found it quite intuitive to go through the above process and its part of the fun of the game. Also, if it looks wrong, it normally is wrong in some way or another. So well-flying rockets tend to be not too stumpy, not too thin etc and the engines look about the right size for their job.

[Spricigo]

56 minutes ago, TitiKSP said:

20 hours ago, steuben said:

Define super heavy.

Starship Super-Heavy.

In that case, the best engine is the best engine.

Seems we are now in a stable orbit.

 

So far your question is as vague as it can be, need clarification if you expect more than some vague ideas on how to figure it yourself. 

 

[Wobbly Av8r]

According to Wikipedia, the "Starship Super-Heavy" anticipates using ~28 Raptor engines, each of which produce ~2,200 kN of thrust in order to place a 100,000 kg payload into orbit from a lift-off weight of ~5,000,000 kg, so assuming these are the milestones defining what you are attempting to reproduce, I would approach the problem like this:

While KSP may not be completely realistic, one of the ideas it replicates with reasonable integrity is the idea of compromise depending on what's important to the designer. The reason you see so many answers is because there really are a large number of ways to do this, but each has its strengths and weaknesses, implementation-wise.

• If part count (computer performance) is the primary issue, the Mainsail will give you the most thrust per single unit for lift-off, although the less "packageable" Mammoth (which is a single part by count but is essentially a bargain package of 4 Vector engines with cost and weight savings) would be your likely candidates. Because the Mammoth form-factor has many TWR advantages, the creators made it, like the Twin-Boar, difficult to make clusters out of, but of course, anything is possible in KSP if you know the right tricks....
• If cost is the primary issue, a cluster (more like "swarm") of cheaper engines like the Reliant are commonly ignored but possible; roughly speaking, 7 Reliants = 1 Mainsail in lift-off thrust but 7,700 Kerbucks =/= 13,000 Kerbucks (but part of the trade-off is 8.75 tons for the cluster vs. 6 tons for the single Mainsail, and so on...)
• If efficiency is the primary issue, it'll be hard to beat the Mammoth but is compromised by the form factor; using the Vector individually helps solve the form factor issue but is hugely expensive.

So you see, there are any number of ways depending on what is most important to you.

[Mikenike]

On 12/9/2020 at 10:49 AM, TitiKSP said:

I was making Starship Super-Heavy then I think would would be the best engine?

Mamoth, Rhino, Vector, MainSail. Make it a cluster form.

[DerkyJerkyWreaksHavoc]

On 12/9/2020 at 11:49 AM, TitiKSP said:

I was making Starship Super-Heavy then I think would would be the best engine?

Vector engine because it has high Gimbal and high TWR.

Starship is very difficult to build accurately (not because building is hard but landing is almost impossible. Even Vector engines don't have enough Gimbal to flip it around and it always likes to dip nose first. i can build starship accurately but not fly it accurately. Super heavy would be good with Vector and Engine pylons for landing legs.

 

[Mikenike]

50 minutes ago, DAFATRONALDO2007 IN SPACE said:

Vector engine because it has high Gimbal and high TWR.

Yeah, it will need around 15-28 of them to achieve the optimal flight profile, despite the lack of efficiency. Well, the Starship is a 9m wide craft, so, it would be eay to stack lotsa fuel tanks in te fairing you'd use to get the starship's shape. At that poin though, I'd be worried about the speeds tthe vector would bring you to. Especially in the first few minutes of the ascent.