Worst engine in KSP

[W. Kerman]

Do they get you to space? 

[Corona688]

I no longer think I have any "useless" engines unlocked in my tech tree so far:

• Ant:  Used it.  Gets you stupid-huge delta V on tiny probes and lets you build smaller than you could with ion.
• Spider:  Nice for boosting tiny satellites from mid-atmosphere up, a region the ant sucks at.  Could have uses in Jool and Laythe.
• Spark:  It fits a narrow gap between terrier and ant.
• Twitch:  It's decent for little orbital probes which need their front and back ends for clamps/grabbers/heatshields.
• Thud:  As a power-up when your main doesn't have enough thrust to circularize, it's nice.  As a main engine, it still sucks! 
• Reliant:  Used it as a kind of "extra big thud".
• NERVA:  Worth the hassle of building into big landers.  A ton of engine can save 10 tons of fuel.
• Poodle:  A nice circularizer for 10 ton craft where Terriers don't have enough oomph.
• Swivel:  A nice 20K+ midstage when you need strong vector control on a smallish payload.
• Skipper:  Excellent for medium payloads from liftoff to circularization in combo with Kickbacks and/or Thuds.
• Kickback:  Just one beats entire multi-stage assemblies of early tech parts.  Six of them can boost amazing things.
• Thumper:  The engine that makes orbit something reliable.
• Flea:  There's a big gap where it's not useful, but early-game it's a low atmosphere lifter, late game it's an automatic deorbiter.
• Hammer:  It and a pair of spiders can reach orbit.
• Sepratron:  Good at exactly what it's intended for.
• Puff:  Ultra-small RCS vehicles where two kinds of fuel tanks would be egregious extra weight.  Orbital assembly and stuff.
• Mainsail:  No gimmick, just bloody big.
• Twin Boar:  TBH I haven't used this one yet, but I should.  The simplicity is appealing.

Edited August 25, 2016 by Corona688

[Cunjo Carl]

@Corona688
     Totally give the twin boar a try. If you subtract out the weight of its included fuel tank, it's actually got the best TWR in the game!

(Separately)
     I think the flea is getting a bum rap- It's great! It's got the cheapest thrust in the game by a good factor and has a 9sec burn time which is perfect for pushing your rocket up to speed from the launch pad. Sure you don't get the Saturn V showy slow rise, but you save a lot of time (=fuel) speeding up if you let a dozen fleas help push you off the launch pad. Also, they're great for separating stages in atmo on monster ships. Fun stuff.

Go fleas! *ahem*

[cantab]

IIRC in career the Twin Boar also offers excellent thrust per credit, when you take into account the integral fuel tank.

[maccollo]

10 hours ago, Cunjo Carl said:

@Corona688
     I think the flea is getting a bum rap- It's great! It's got the cheapest thrust in the game.

But it's impulse/cost ratio is garbage. You get 8448 Ns per fund. Jump just one step up to the hammer, and you get 13450 Ns per fund, and the kickback gets 15584.

Edited August 26, 2016 by maccollo

[magnemoe]

Main issue with the fly is probably the look, it should been an longer and thinner. And yes have used them some times then an smaller rocket need some more kick. 

[Sharpy]

About flea: Current plan: quad-kerbal descent capsule with zero parachutes and no LF motors.

Separatrons for reentry burn. Airbrakes to lose speed. Flea for final braking burn. MK2 passenger capsule so that any remaining speed mismatch is survivable (good impact durability)

[KerikBalm]

2 hours ago, magnemoe said:

Main issue with the fly is probably the look, it should been an longer and thinner. And yes have used them some times then an smaller rocket need some more kick. 

I assume you mean the flea... and yes people were hoping for a 0.625m SRB. I think the issue with that would be that career starts out with just 1.25m parts.

A 0.625m SRB with a 1.25m capsule on top of it would look weird.

IMO the stayputnik needs to be unlocked from the start, so at the very beginning we can have unmanned probes. At that point, we can also have a 0.625m srb

[Sharpy]

Eh, flea was way too OP for the job.

 

That's all. 7760 funds. 16 parts. Max tech level 7 (MK2 cabin). Airbrakes moved using the move tool. Separatrons not tweaked in any way.

On orbit of 100km above the mountains in the middle of the desert activate SAS retrograde, fire the first four separatrons and click the brakes action group.

At about 250-300m altitude fire the remaining separatrons (lower for splashdown, higher in highlands).

 

(conclusion: for some applications, Flea is overpowered.)

Edited August 26, 2016 by Sharpy

[Corona688]

5 hours ago, KerikBalm said:

I assume you mean the flea... and yes people were hoping for a 0.625m SRB. I think the issue with that would be that career starts out with just 1.25m parts.

Not exactly, the 0.625m form factor comes from the original starter parachute.

Quote

A 0.625m SRB with a 1.25m capsule on top of it would look weird.

So cluster 6 more around it

Quote

IMO the stayputnik needs to be unlocked from the start, so at the very beginning we can have unmanned probes. At that point, we can also have a 0.625m srb

The stayputnik unlocks really early already.  I wonder if the probodyne unlocks too early, it's just so much better than the stayputnik -- lower power, hardpoints, reaction wheels, for nearly the same price and smaller form factor.

What I think should unlock earlier are solar cells or perhaps fuel cells, without which all probes are short-lived disposables.

Edited August 26, 2016 by Corona688

[SpacedCowboy]

The 24-7s Spark. R.I.P.

Used to be the best, now it's the worst.

[linuxgurugamer]

On 7/3/2016 at 9:59 PM, Brownhair2 said:

The Flea may never be used, but that doesn't make it bad. I'd say the Ant and the Spider, since those are the only engines I have never used. Not even once

Both of those are great for interplanetary probes.

[Sharpy]

Agreed, Ant is mighty with tiny probes. I was sceptical at first too, then I strapped one to the smallest MK1 tank, saw the delta-V in KER and was sold. Seriously, that's what I mean overengineered: engine for miniature Eve landers, for deorbiting. Capable of performing the deorbiting burn of... 4000m/s.

And I really, really wish for a buff for Spark. Leave the low ISp - but give it a better thrust!

This baby was handling fine, but I didn't want it to handle fine, I wanted it to handle dangerously!

 

[SpacedCowboy]

Yeah, I used to include the Spark in all of my Kerbin  SOI landers,,, but not anymore.

It's a pity they smurfed it down so much!

[magnemoe]

On 4.7.2016 at 3:59 AM, Brownhair2 said:

The Flea may never be used, but that doesn't make it bad. I'd say the Ant and the Spider, since those are the only engines I have never used. Not even once

Weakness with the flea is poor vacuum isp, main benefit is that two of them give twice the power as an ant and the ant look stupid being suspended above the decopler. 
Flea is pretty nice for an probe / lander around an low gravity world, as you can land on the tank, or have an bottom docking port for reuse / refueling. 

13 hours ago, SpacedCowboy said:

Yeah, I used to include the Spark in all of my Kerbin  SOI landers,,, but not anymore.

It's a pity they smurfed it down so much!

Spark is still very nice, yes the reduced trust and the improved ant make its window smaller. 

[Red Iron Crown]

Spark used to be really OP, it was basically the best engine for almost everything if part count wasn't a factor (and even then it was best in a *lot* of situations). 

[Zoidos]

I use.the poodle for most of my 2.5m rocket designs. Great isp for a lfo engine, small footprint, not too heavy. Especially useful before unlocking nukes a very handy tool for interplanetary manned exploration.

[Sharpy]

10 hours ago, magnemoe said:

Weakness with the flea is poor vacuum isp, main benefit is that two of them give twice the power as an ant and the ant look stupid being suspended above the decopler. 
Flea is pretty nice for an probe / lander around an low gravity world, as you can land on the tank, or have an bottom docking port for reuse / refueling.

Don't you mind Spider?

I'm seriously trying to imagine a Minmus lander using Flea... now that would be an interesting challenge...

[Corona688]

11 hours ago, Red Iron Crown said:

Spark used to be really OP, it was basically the best engine for almost everything if part count wasn't a factor (and even then it was best in a *lot* of situations). 

Reducing its ISP, or reducing its thrust, would have been reasonable, but not both.

1 hour ago, Sharpy said:

I'm seriously trying to imagine a Minmus lander using Flea... now that would be an interesting challenge...

Hm..  Clip a decoupler inside them perhaps, so you can force them to detonate on command.

[Armisael]

I've never found a good* use for:

• The Reliant has lower Isp than the Swivel after ~3.2km, and less thrust and more expensive than a Thumper. What's the proper use case here?
• The Spider has terrible Isp across the board and its thrust is so low that they can't be used on anything other than an Ant-based ship. The gimbal won't matter on a probe, because the core has a reaction wheel. I guess I could see it on an OKTO2-based satellite or a super lower TWR command-chair build. Blech.
• The Twitch and the Thud both have the same problem as the Spider but without even being super lightweight. They're only even remotely justifiable on lifters - why not asparagus (or use an SRB if it's the first stage)?
• The Puff. I have literally only once wanted to use this engine, and it was in a challenge that outlawed oxidizer/xenon/solid fuel outright. Why not use a Spark for nearly the same weight? It isn't exactly difficult to dock a tiny ship without RCS anyways.

(I have seen good use of some these engines in ultra-hardcore cost, weight, or size based challenges where things like practicality go out the window, but that isn't what I judge these things on most of the time).

Engines I've seen ragged on that I'd like to defend:

• The Spark is my go-to engine for satellites and airless body landers. Sometimes you need to squeeze out every last drop of dv, in which case the Ant (or a Terrier) may be more appropriate for a satellite, but it's small, light, and provides great thrust for most satellite maneuvers in Kerbin's SoI. Double-Spark landers carrying two cans are weight-competitve with Terrier designs in the 1-2 km/s dv range and have a low enough CoM to not need legs. (That last bit is a big perk in my book - legs are heavy!)
• The Flea is useful as a first-stage kick, as mentioned earlier. Later SRBs may be cheaper per impulse, but they also take forever to burn. I want to get going quickly but then I don't need that acceleration; nine seconds is about right. The next smallest SRB burns for twenty-four, which means that ride just got a lot wilder than I wanted.

Edited August 27, 2016 by Armisael

[Sharpy]

8 minutes ago, Armisael said:

I've never found a good* use for:

• The Spider has terrible Isp across the board and its thrust is so low that they can't be used on anything other than an Ant-based ship. The gimbal won't matter on a probe, because the core has a reaction wheel. I guess I could see it on an OKTO2-based satellite or a super lower TWR command-chair build. Blech.

Don't you diss the gimbal.

There would be no above story had I gone with Spiders instead of Ant.

[Corona688]

10 minutes ago, Armisael said:

The Reliant has lower Isp than the Swivel after ~3.2km, and less thrust and more expensive than a Thumper. What's the proper use case here?

On 8/25/2016 at 1:32 PM, Corona688 said:

• Thud:  As a power-up when your main doesn't have enough thrust to circularize, it's nice.  As a main engine, it still sucks! 
• Reliant:  Used it as a kind of "extra big thud".

Also, the Spider gets much better ISP than the Ant in-atmosphere.

[Armisael]

2 hours ago, Sharpy said:

Don't you diss the gimbal.

There would be no above story had I gone with Spiders instead of Ant.

A botched mission that turned into an amusing story isn't exactly a great argument for the engine's viability.

EDIT: I think I came out a bit harsh there. Ultra lightweight probes where an extra 30kg is a serious issue is one of the few worthwhile use cases for the Spider. It's the best on my junk list IMO.

2 hours ago, Corona688 said:

Also, the Spider gets much better ISP than the Ant in-atmosphere.

I don't believe that there's a lifter using thuds or reliants that couldn't be designed better without them. Can you give me an example? 

As for the spider - what's the actual practical case where the lifter can't easily finish the job and where a spark won't work?

Edited August 28, 2016 by Armisael

[Corona688]

3 minutes ago, Armisael said:

I don't believe that there's a lifter using thuds or reliants that couldn't be designed better without them. Can you give me an example? 

Anytime you need more thrust than the Skipper but the mainsail is overkill.

Quote

As for the spider - what's the actual practical case where the lifter can't easily finish the job and where a spark won't work?

When I realized the spider had good atmosphere performance I set out to use it somehow.

Mostly though, like any radial engine, they're for getting out of corners.

Edited August 28, 2016 by Corona688

[Armisael]

1 hour ago, Corona688 said:

Anytime you need more thrust than the Skipper but the mainsail is overkill.

I believe that in the vast majority of those cases you're better off either using SRBs (if it's a first stage) or distributing fuel to stacks farther out (if the inside of an asparagus).

1 hour ago, Corona688 said:

When I realized the spider had good atmosphere performance I set out to use it somehow.

-snip-

Mostly though, like any radial engine, they're for getting out of corners.

Atmo's really pretty thin. The Ant reaches the Spider's Isp at 12.2 km, at which point it has 92% of the Spider's thrust. That design works just as well with a pair of Ants (if not better, due to more dv and less drag from a reduced cross-section). I don't know exactly what thrust limit you used, but the hammer carried above that line in every design that didn't explode from heat.

Edited August 28, 2016 by Armisael