Making a rocket with out accidintly making it into an SSTO?

[Cloakedwand72]

Hi everyone do you have any tips on how to make a proper multi stage rocket with out accidently making it into an SSTO with both squad stock parts & modded rocket parts?

[MoarBoostersRUS]

Make a rocket with boosters 

[Blaarkies]

Such first-world problems, most people struggle just getting into orbit

Increase your payload mass...you will definitely need to add MOAR BOOSTERS!

Jokes aside, use the ratio rule:
- Payload is 1t
> add a fuel tank + engine with a mass of (1x2)t
= this stage(with everything above it) is now 3t in total

> add a fuel tank + engine with a mass of (3x2)t
= this stage(with everything above it) is now 9t in total

> add a fuel tank + engine with a mass of (9x2)t
= this stage(with everything above it) is now 27t in total

...
That is a 3-stage rocket that will probably get into orbit twice. If you like more stages, just replace the multiplier "2" with something smaller, like "1" or even "0.5"

[Jognt]

On 11/3/2017 at 4:43 AM, Cloakedwand72 said:

Hi everyone do you have any tips on how to make a proper multi stage rocket with out accidently making it into an SSTO with both squad stock parts & modded rocket parts?

Make your first stage way smaller, make your second stage bigger, maybe add a seperate transfer stage.

If you're concerned about reusability, try FMRS.

OR: Add MOAR boosters...that point retrograde. That'll make sure it won't reach orbit on its first stage

edit: Watching the SpaceX launches amazed me in terms of how quickly they stage to the second stage compared to my 'first stages' that make orbit on their own.. Maybe check their casts on youtube for inspiration? (bonus points for landing your boosters on a droneship on the coast)

Edited November 5, 2017 by Jognt

[Vanamonde]

Thread moved to Gameplay, since it is seeking help rather than offering it. 

[Geschosskopf]

On 11/2/2017 at 10:43 PM, Cloakedwand72 said:

Hi everyone do you have any tips on how to make a proper multi stage rocket with out accidently making it into an SSTO with both squad stock parts & modded rocket parts?

Hehehe, most folks have the opposite problem of not getting to orbit at all  

Anyway, what you're doing is building the rocket with way more dV in the 1st stage than you need to reach orbit.  As KSP provides no in-game way of knowing what your rocket's dV is, you either have to calculate that yourself outside of the game (which is a pain) or use a mod like KER or MJ that will do this for you within the game.

On top of this, you also need to know how much dV you need to go various places.  There are a variety of "dV maps" available so pick the one you like (be sure it's for post-1.0, though).  With such a map, you'll know how much dV to build into your rocket, and KER or MJ will tell you when you have that.  For example, you only need about 3800m/s to reach LKO (depending on trajectory, your rocket's drag, etc.)  So, if you wanted to use 3 stages to get to orbit, you just divide that total up across the 3 stages.

Really and truly, however, if you can make an SSTO rocket, you're often better off in the long run.  Fewer parts, no way to accidentally mess up the staging sequence, etc.  But the ability to do this is a function of the payload mass and the size of the biggest rocket parts you have, so often isn't possible.

[OhioBob]

Rescale the solar system to 2.5X.

[Aegolius13]

I would try using a smaller/less powerful engine for launch.  You will probably need to cut back fuel to get an acceptable TWR.  And that will likely all mean less delta-v on the first stage.

[tutike2000]

Post a pic of your rockets? Not sure what your payload is, compared to the rest of the rocket.

[Nightside]

Add more payload.

[Tyko]

On 11/5/2017 at 7:57 AM, OhioBob said:

Rescale the solar system to 2.5X.

THIS...when I moved to 2.5x scale using stock parts my rockets suddenly started looking "realistic" - minimum 2 stages to orbit and 3 stages to the moon. Made it challenging, but still accessible

[GoSlash27]

*edit* Revised for brevity and kindness...
Try the Caveman challenge. If you learn how to operate that way, you will never accidentally over- engineer your rockets.

Best,
-Slashy

Edited November 14, 2017 by GoSlash27

[Superfluous J]

Make sure your bottom stage has less than 3000 m/s dV.

[HeliosPh0enix]

I wish I had this problem, seeing as I can't seem to design reusable anything to save my life.  Are you using Kerbal Engineer Redeux?  Even if you want to avoid mods, I think this one is good to use because it just gives you lots of information to interpret.  Generally when I design my rockets, I like to have a 1.5-1.7 TWR on the first stage, but it can be more or less as long as it isn't too close to (or below) 1.0 and not too high as to make the rocket break up from atmospheric stresses.  According to most delta-v maps, you only need 3400 delta-v to get into LKO, but that requires I pretty good ascent profile and I am generally terrible at the game, so I try to design my rockets with between 3700 and 4000 delta-v in the stages meant to get it to orbit.  I usually design it with a central stack and two liquid boosters attached with fuel lines.  I usually hit orbit with a little fuel left in the central stack, which I use to help get me wherever I'm going.  This is definitely not the most efficient or even easiest tactic, but I like it and it works for me, so it might work for you.

[Dafni]

Or use the remaining dV to make a boost-back and landing of the first stage, like SpaceX does???

[Superfluous J]

4 hours ago, HeliosPh0enix said:

I wish I had this problem, seeing as I can't seem to design reusable anything to save my life.

Note: SSTO =/= Reusable. All it means is that you can get into orbit without staging.

You can build a pretty simple SSTO early in the tech tree with (top to bottom) a parachute, Mk1 command pod, decoupler, multiple fuel tanks, Swivel. It's ugly, inefficient, anything but reusable, but it's the first and only SSTO I build in every single career, specifically to clear out 2-3 of the first 4 contracts (launch, space, orbit).

[Van Disaster]

7 hours ago, 5thHorseman said:

Note: SSTO =/= Reusable. All it means is that you can get into orbit without staging.

Should probably add a disambigutation to the mouseover for that... SSTO, Reusable and Spaceplane are all intersecting sets, but none of them overlap completely.

To the OP: Sounds like you're building *way* too big ( which means too expensive too ) - try building as cheap as possible, barely staggering into orbit on a shoestring.

Edited November 14, 2017 by Van Disaster