Launching a Payload

[Liam Sheepman]

I need to launch a 22.23 ton payload (it's a Mün base) to the Mün. The payload comes with the necessary tools for landing, so no need to explain the land stage. I can get up to a decent height, but I can't circularize my orbit at my apsis. I kinda suck at rocket design. Has anybody got any suggestions for a Mün-travel capable launcher? I've been to the Mün before and landed, so I really only need assistance with the design. It seems like I've tried everything. Can anybody help?

Edited August 4, 2013 by Liam Sheepman

[painking]

We'll need a picture of the craft if you want help on that regard. It may be that your launch stage doesn't have enough fuel to get it up there and also circularize or at least get the majority of the circularization done.

[Scorpi15]

Add more orange tanks with mainsails underneath them for the booster stage. I think six is enough to have a large margin for error.

[Specialist290]

Like Scorpi15 hinted at, in general it's a good idea to add extra fuel to your very first stage, or even another "booster" stage altogether.

[Johnno]

Here's a post I made for another thread that should be helpful.

To get your base from Kerbin orbit to Mün orbit you should be ok with a Rockomax X200-32 fuel tank and poodle engine below your payload, even a bit less fuel would be fine. My go-to quick & easy lifter that I show in the other post should get your base + the Rockomax X200-32 & poodle combo up into orbit without trouble.

[Jason Patterson]

Your best bet is to post a picture and/or craft file for the vessel that you've already built. It's a lot easier to give advice based on something rather than just throwing things out randomly and hoping that one of them applies.

I'm not sure how you're trying to fly your rocket, but it sounds like your ascent profile might be a bit off as well. If you aren't doing a gravity turn at around 10km altitude then it's likely that you're wasting lots of fuel trying to gain height instead of getting to orbit.

[DisarmingBaton5]

When in doubt, abandon aesthetics and use triple layer asparagus.

"Don't forget struts!" -Bob Kerman

[Francesco]

is it 22 tons to orbit, or 22 tons to Mun surface?

[Liam Sheepman]

I tried launching it with a 7-orange-tank triple-layer asparagus section, and then I tried (in two different designs) a nuclear stage and a Rockomax X-200-16 with a Poodle engine. Both times it failed to circularize, and I had to revert the flight.

Here's the craft, sorry you can see the rest of my screen - cropping fail.

I do try to start my circularization right at my apsis. Maybe I should try replacing the Rockomax X-200-16 with an X-200-32, like DisarmingBaton5 said, and burning early? I'm normally very good at orbits.

[Anton P. Nym]

LV-Ns and Poodles aren't terribly good choices for circularisation; they're efficient, but their TWRs can't finish the job before gravity does. Try swapping a Skipper in for the Poodle; you'll burn up more propellant, but you'll finish the burn in time.

(If this is also your transfer stage, you may want to consider making another stage with your high-I(sp) engine and a smaller fuel tank, though that does risk adding too much weight.)

-- Steve

[Liam Sheepman]

LV-Ns and Poodles aren't terribly good choices for circularisation; they're efficient, but their TWRs can't finish the job before gravity does. Try swapping a Skipper in for the Poodle; you'll burn up more propellant, but you'll finish the burn in time.

(If this is also your transfer stage, you may want to consider making another stage with your high-I(sp) engine and a smaller fuel tank, though that does risk adding too much weight.)

-- Steve

That's not my transfer stage. That's the actual lander. 22.23 tons to the Mün surface.

[MrPopcup]

weight is not a problem for you, the problem is the size of it, Launching a mun base in one launch is pretty freaking hard! I once launched a mun base - which is kind of a ramp to make rovers/landers dock with it and refuel. it was only 11 tons and had many issues with the skycrane, I ended up with 3 engines on my sky crane just to balance it and then took it to the moon.. was pretty hard.. I suggest you to take everybit of this base to kerbin's orbit, then dock them together and send them to the mun, or if you want it to be easier, take everything to the mun and dock there, low gravity and low velocity ( for orbit ) will really help you to dock easily.

P.S: Today I checked up my station in kerbin's orbit ( 500 KM ) and it was low on fuel and RCS, I made a rocket to refuel it, the rocket ( orange,Jumbo tank ) with 4 little 90L tanks on sides with 4 nuclear engines mounted, I took this 50 ton thing all the way to my spacestation and refueled it, fps were 10 duing launch, just to make you understand how hard is this!

[Liam Sheepman]

weight is not a problem for you, the problem is the size of it, Launching a mun base in one launch is pretty freaking hard! I once launched a mun base - which is kind of a ramp to make rovers/landers dock with it and refuel. it was only 11 tons and had many issues with the skycrane, I ended up with 3 engines on my sky crane just to balance it and then took it to the moon.. was pretty hard.. I suggest you to take everybit of this base to kerbin's orbit, then dock them together and send them to the mun, or if you want it to be easier, take everything to the mun and dock there, low gravity and low velocity ( for orbit ) will really help you to dock easily.

P.S: Today I checked up my station in kerbin's orbit ( 500 KM ) and it was low on fuel and RCS, I made a rocket to refuel it, the rocket ( orange,Jumbo tank ) with 4 little 90L tanks on sides with 4 nuclear engines mounted, I took this 50 ton thing all the way to my spacestation and refueled it, fps were 10 duing launch, just to make you understand how hard is this!

Alright. So, how about I separate it into the actual lander craft with the hitchhiker pod, then I send some rovers with all the other attachments to the Mün and dock them with that craft?

[Specialist290]

He should be able to get that thing to the Mun in one shot; I've done similar things with objects of about that size and weight before.

That said, what does the whole rocket (launcher + lander) look like, and what stage is the one that's giving you the trouble?

[Liam Sheepman]

He should be able to get that thing to the Mun in one shot; I've done similar things with objects of about that size and weight before.

That said, what does the whole rocket (launcher + lander) look like, and what stage is the one that's giving you the trouble?

(I separated the first part so that the engine wasn't covered by a fairing.)

It usually messed up at the stage labelled 3, which is actually the 4th stage, after all the radial-mounted mainsails have decoupled.

[painking]

That should get the mun no problem if you just swap out that Poodle for a Skipper. In fact, swap your main asparagus engine to a skipper as well, you've got more than enough lift power with 6 Mainsails. The skipper is also more efficient and should be able to perform the circularization burn no problem, and if it runs out of fuel, the the next stage's Skipper will finish the job.

[Liam Sheepman]

Thanks MrPopcup! I took of those side bits and added some docking ports and it landed just fine, with plenty of fuel to spare! Now to dock on some transports.