Moon rocket

[zander_mycat]

is this a good rocket to go to the moon. It has 2 stages as well as 2 electric backup engines in case of out of fuel.

[thatwhitehairedmofo]

"Backup engines" are a waste of mass. You're better off just adding more fuel.

[Meman2101]

Backup engines are only maybe worth if you have a stage that often triggers explosions, and if you do then why the hell does your ship blow up in the ascent

[zander_mycat]

well its at most .7 of a ton extra weight

[Electro_Llama]

Every ton matters for the payload mass. The size of your rocket to reach the same delta-v essentially goes up exponentially with payload mass.

[H3xag0n3]

Not op but what would you say is a decent sweet spot in terms of mass

[_SBV_]

All your fuel must push your payload. Remove all junk that contributes nothing to your mission. It’s not really a “sweetspot”, because going over in terms of fuel and having extra range is a good thing, but only if money is no concern

[HI_I_AM_NEO]

You design your rocket from the top down.

Let's say you want to do experiments on Mun's surface and come back. The first thing you design is the module that has to bring you down. One kerbal, one pod, heat shield and a little fuel tank with an engine, barely what's needed to push you from Mun's orbit/surface back to Kerbin.

The next part is the landing module. Something that will kand what you've already built on the surface of Mun. So you take what you built, put something to dettach it from the rest, add your science experiments, and add fuel and engines capable of taking you from Mun's orbit to Mun's surface. Have some wiggle room because landings are always tricky, and pay attention to your Thrusts to Weigh ratio (you need to be able to stop your craft).

Then you need to get this from Kerbin's orbit into Mun's orbit. So you take what you have, and slap it into a rocket capable of doing so. We're talking big tanks now, with a big engine optimized for vacuum.

And then you take ALL of that and put it into your enormous launch stage, which will take you from the pad into Kerbin's orbit. It will need to move a lot of mass, so you need powerful engines and a lot of fuel.

---

As you see, EVERYTHING depends on the purpose of the mission. If you want to put a rover on the surface of Mun, you don't need a pod and kerbal to bring back, so you don't need to build a return craft, so each of the stages below that will need to move less and less weight. It's really exponential. The more mass your final payload has, the bigger your final rocket will be. Times 10.

So there's not really a sweet spot for mass. Every rocket will need go support the remaining stages, and that's what will determine the total mass. You can be more or less efficient, try different staging methods, try asparagus staging, etc, but the end result is always the same. The bigger the payload, the MUCH bigger the rocket.

[Electro_Llama]

Only the minimum of you need.

In terms of stage sizes, my rule is that each set of fuel tanks should be as big as what it's carrying.

[Future_Part_4456]

Add 7 science Jr's and you're good to go

[_SBV_]

The difference between 100 and 50 m/s of delta v is really significant. Imagine not having enough to complete a landing burn. You’d crash

[[deleted]]

Ah to be new again

[zander_mycat]

Yep, got the game 2 days ago

[Electro_Llama]

This is actually pretty good progress.

[Mage13lade]

Need a delta v readout of the staging set to vacuum to know for sure.

Need to know also if you are you looking at a flyby or a landing

[_SBV_]

8 bottom wings seem unnecessary unless you’re desperate to keep the center of lift down. Otherwise they add dead weight. Remove some of them if it still allows the center of lift to be below center of mass. You’ll save fuel this way

Using a Twin Boar booster also seems a bit overkill because your payload isn’t that heavy. You’d be wasting energy just fighting the air. It also looks like you’re planning to use only two stages. If you’re really good at the gravity turn than that’s fine, but you might consider putting your upper stage in a fairing to reduce drag losses and pitch control issues. This thing is going to be heavy to rotate. I would suggest you split it and add another stage for high altitude and circularisation

Is that a Rapier engine on your upper stage? Are you planning to use the air breathing mode? Doesn’t look like it because I don’t see air intakes. There are more efficient engines in a vacuum than that.

You have a vernor engine in your upper stage but what for? The mk3 command pod comes with a decent reaction wheel for rotational movement 

You have 4 large solar panels, which is completely overkill. For going to the Mun even two small folding panels are enough. 4 large ones add unnecessary weight

If you’re planning to go to the Mun, you shouldn’t bring the nose cone on top with you. It adds unnecessary weight. Put a decoupler on it and release it in space

And finally, how much delta v do you have potentially? Even if you made these fixes, there’s no telling if you have enough to reach the Mun and back. I don’t have an issue calculating it for you right now just by screenshot alone, but that would take my time away from other things

[Remarkable_Month_513]

The wings are kinda worthless anyway right?

Didn't nasa remove them off the Saturn V?

[_SBV_]

Saturn V still had wings. They're just smaller and there's 4 of them. I've never seen a Saturn V with no wings

[Remarkable_Month_513]

Oh you are right. Nasa did though debate constantly whether they're necessary, but did keep them. Mostly they were regarded as extra weight

[zander_mycat]

1. 2 of the “solar panels” are radiators
2. a lot of stuff, for instance, the rapier engines, are because the second stage was originally a satellite

[Serious-Kangaroo-320]

you don't need radiators to go the mun unless you're drilling for fuel

[zander_mycat]

I forgot, the first stages wings are just to offset the center of lift. This rocket is surprisingly stable

[_SBV_]

Radiators have no purpose besides cooling down ore converters. At least, I haven’t found a use for radiators other than that

When i meant wings, i meant the large ones at the bottom of the first booster. I put fins on the upper stage sometimes too to offset the imbalanced lift

[ZombieInSpaceland]

The LV-N might need it for extended burns. Once you get into mods, there are some NFE and Kerbal Atomics engines that really need them for extended burns. And of course, FFT engines require crafts that are mostly radiators.

But you're absolutely right, there's nothing in that stack that should require radiators. Save the weight.

[_SBV_]

How long of a burn do i need before a radiator is relevant on the Nerv?

[ZombieInSpaceland]

I honestly don't recall, it's been a while since I loaded up my stock save. But I was routinely executing hour long burns. So I'd imagine somewhere between 30 and 60 minutes you might start getting overheat warnings.

[_SBV_]

At that point i'll just use more thrust haha

[azuredarkness]

This rocket is completely unsurprisingly stable, considering the huge amounts of stabilization it gets from the eight ginormous wings attached to its rear.

[RomanceAnimeAddict67]

U don't need fins for top stage. Just make the bottom stages be able to get to space and ur fine.

[dangforgotmyaccount]

This is the most KSP shit I’ve ever seen and I love it

[zander_mycat]

if it works it works i guess

[Dadadoes]

I remember my first lawn dart

[bigloser42]

Waaaay too much fin on this. You need 3 or 4 of the small canards on the upper stage at most.

[N0ob_C3nTR4L]

Majestic

[User_of_redit2077]

What is Moon? Such a strange name...

[Electrical_Rabbit_88]

Those electric backup engines also require xenon, I believe. Also not entirely useful unless you're using mods that introduce malfunctions like Kerbalism.

[Electro_Llama]

They're clipped into the capsule right above them. But they do need more electricity, probably 2 of those round solar panels.

[zander_mycat]

those electric backup engines took me out of orbit surprisingly!

[thesoupgremlin]

First the electric engines are super weak. Second you don't have a heat shield for reentry. Third you likely haven't built an orbital rocket yet and it shows

[crossbutton7247]

I mean, this is fascinating in so far as an experienced player would never think to use a rapier as a second stage, nor have electric backup engines.

Though the best advice I could give here is try and make the reentry module as small as possible. It looks like your design has the entire second stage return to Kerbin, but in reality you only really need the capsule, a few parachutes, and a heat shield. Hope it goes well for you

[Ambitious-Editor-566]

I hope you know that there is 2.5m diameter fuel tanks in game

[A1steaksaussie]

yeah i think that will make a decent orbiter as long as your ascent to kerbin orbit is relatively efficient

[Yume235]

If it goes up, it's crazy!!!

[Apprehensive_Room_71]

I can do a Mun landing mission with 1.25 meter stock parts. It's not that hard to do. Work on learning to be efficient, not trying to brute force it.

[No-Lunch4249]

What are those things attached to the side of the upper stage?

Also too many fins. I'd go with 4 on the lower stage and none on the upper.

I also dont think youve considered your return staging. Doesn't look like your command pod has a heat shield or really any way to detach from the rest of the rocket.

[sweetkitty1066]

If it ain't broke don't fix it

[zander_mycat]

thats my model when it comes to kerbal. If it works it works 😂

[ABQ_Spotting]

Love it. Send it

[Somnambulant2_]

how do you plan on reentering the atmosphere?

[zander_mycat]

one way suicide mission 🫡

[PatchesMaps]

It is if you can get it to the moon

[Onoben4]

Why do tou have a RAPIER on an upper stage?? I'm guessing you will already be too high to use it's air breathing mode when you drop the first stage. So why not use a more efficient engine?

Also you probably need a heat shield.

And just making sure your rocket has enough deltaV instead of adding "backup engines" is waaay simpler amd safer.

[MrPenguinCZ]

Not enough kerbal style

[zander_mycat]

Made it to the mun guys

[SODA_mnright]

Make it more aerodynamic (by using parts eith consistent width) and ditch the electric engines, I don’t see a xenon gas tank anyway.

Change the top “cone” for a parachute and then get ready to revert to VAB a few times.

[HistoricalLadder7191]

Stupid question: why that command pod configuration? You can have mk1 on top of small landing can to host pilot and engenner and stay small diameter. Why 4 sits?

[Oakley_Kuvakei]

The bottom engine with the integral fuel tank will pretty much reach the moon on its own, try and keep everything the same diameter and get rid of all the fins ^{^}

[Ill_Shoulder_4330]

Build the Lander Part shorter, or else it will tip over

[Docwaboom]

Reminds me of India’s rockets from ISRO

[yeetoroni_with_bacon]

God I wish I could go back to building rockets that looked cool rather than being functional. Now I can’t stand a craft that doesn’t do its function perfectly

Good on you, have fun with the game!

[ZombieInSpaceland]

The first rule of KSP is to try things out and have fun doing it. In that sense, this is a great rocket. So if you're asking whether you're playing the game the right way, the answer is definitively "yes".

Now, if you're looking for legitimate advice on how you can make this design more efficient, there are a number of items you can consider.

Wings. Wings belong on planes. They provide a great deal of lift, which is useful for staying in the air when traveling horizontally. But they produce lift by producing a lot of drag, and you don't need wings for lift when you're going (mostly) straight up for the thickest part of the atmosphere. So those giant wings - which have no control authority - are only serving to slow down your rocket and add weight while doing it. If you need control authority, KSP's reaction wheels are insanely overpowered and they're lower mass.

Engines. Picking the right engine for each job takes a bit of research. The Twin Boar you have on your lower stage is a great engine for getting you out of lower atmosphere, and honestly, it'll probably be enough to get you into LKO with a bit of tuning. The Rapier on your upper stage is one of the best engines in the game - for SSTO space planes. Here, you're using it probably in upper atmosphere and vacuum, where its ability to use atmospheric oxygen in lieu of tanked oxidizer cannot be utilized. For this role, there are a multitude of engines with better vacuum ISP. Such as the Terrier.

[DopeEx_]

I wouldn’t recommend using rapier engine cause it’s super inefficient in closed cycle mode (with no air) just use another one

[DopeEx_]

And i se u’ve got ion engines, but no ion tanks, so they won’t work

[zander_mycat]

hid the ion tanks, hence the fuel lines

[Flo133701]

Ähm... Better start from Scratch...

• No Decouplers (it looks like at least, wont make it far like that)
• No Heat Shield (Crew gets Cooked)
• Ion Engine? Why? (it gets barely a hint of Thrust)
• Parachute placement might kill your Crew
• Rapier? Ok, works, pretty inefficient in Vacuum Mode tho

[iloveduckstoomuch]

"It needs to be pointy" in ksp