Heavy Payloads (Thanks everybody!)

[Mister Kerman]

Hey guys. I've been trying to make a fuel efficient fuel ship that's capable of carrying an orange tank of fuel (preferably) to a Munar orbit, and dock with a station for fueling manned lander missions. I've come up with a few but these were my best two.

#1

This one did okay but was too plain and ugly, so I vowed to make a better looking one and deleted it.

#2

This model is beefy and cool looking, but bad on gas. It carried about 200 units of fuel in each of the big tanks, and full radial engine rocket fuel(Fuel flows out of the main tanks and into the radial gas tanks.). Not the best payload but enough to fuel a mission. It might be more economical to just send more landers, but I really want my refueling operation to work!

A side note on the second fuel ship: It's my first set of decoupling tanks to include a RC Command Pod for deorbiting the tanks after they've been used up. I'm trying to control how much I leave behind finally!

This is my delivery system and Command Modual. Any critiquing is welcome.

Edited August 23, 2014 by Mister Kerman

[SRV Ron]

An old design with NovaPunch parts. It placed the fuel can into mid Mun orbit.

It can also be done with stock parts.

Of course, one can go bigger easily with this payload of 5 orange cans in orbit.

Enough fuel remains to send it to Mun.

[Sirine]

Sorry, but what was your question again?

[Mister Kerman]

That thing works?

Looks like my brain is so smart that it's dumb.

My next one's gonna look different. I'll try a shorter delivery system. Looks like weight was my enemy.

[KerikBalm]

If it can get 100 tons to LKO, I'm sure it can get at least 50 tons to Munar orbit (particularly using an orbital tug, and not trying to move the whole SSTO+ payload)

It took a lot of trial and error (lets call it refinement) to get it working though. I made a payload for it that was 2 orange tanks (actually, 1 orange, and enough FLT-800s to constitute a 2nd), a nuke, ions, RCS, chutes, a probe core, reaction wheel, and landing legs as a supply ship, since maneuvering the airplane part in orbit would be very inefficient.

[Pecan]

Have a look at chapters 7 and 8 of my tutorial (link in signature) for space stations, reusable transfer vehicles and launching an orange tube.

Meanwhile a couple of comments: I see no docking port on the command module so it's unlikely to need RCS fuel and thrusters. If there is actually one on it then you should be able to dock with the monopropellant in the pod itself, lose the excess mass of the additional RCS tanks.

On your launch system the boosters' exhaust seems to be hitting the lower fuel tanks. This will kill all their thrust even if it doesn't blow up. If those lower tanks are a separate stage then use them after the boosters, which are heavy for their deltaV so should be used and jettisoned as early as possible.

[Wanderfound]

Any critiquing is welcome.

It's hard to tell from the image exactly how your lifter is built, so a few basic principles:

1) With the exception of specialist vacuum engines (nukes etc.), you generally want every engine that you're carrying to be firing at full power from launch. When you're building, try to arrange things so that this is possible. If you don't fire them all at once, you're carrying dead weight, which takes more fuel. If firing them all at once makes you accelerate too fast, your rocket is bigger than it needs to be.

2) You want to ditch weight as soon as you can. Use fuel lines to concentrate your fuel consumption on as few tanks as possible and drop them (and the engines on the bottom of them, usually) as soon as they're empty.

These two points are the basis of onion and asparagus staging. Onion staging drops rings of tanks from the outside in; asparagus staging is similar, but empties and drops alternating pairs instead of rings. Asparagus is slightly more efficient, but onion is simpler to build and control.

3) Watch where your exhaust is going. Rocket go boom.

[Mister Kerman]

I forgot about this thread. I've been doing Apollo missions and haven't had to deal with refueling. I'll try your guys' simpler designs out. Thanks for the help everybody!

[SRV Ron]

1) With the exception of specialist vacuum engines (nukes etc.), you generally want every engine that you're carrying to be firing at full power from launch. When you're building, try to arrange things so that this is possible. If you don't fire them all at once, you're carrying dead weight, which takes more fuel. If firing them all at once makes you accelerate too fast, your rocket is bigger than it needs to be.

2) You want to ditch weight as soon as you can. Use fuel lines to concentrate your fuel consumption on as few tanks as possible and drop them (and the engines on the bottom of them, usually) as soon as they're empty.

These two points are the basis of onion and asparagus staging. Onion staging drops rings of tanks from the outside in; asparagus staging is similar, but empties and drops alternating pairs instead of rings. Asparagus is slightly more efficient, but onion is simpler to build and control.

Exactly the basis of the designs I posted. You can also try different engine combinations like I did with the single fuel can since all Mainsails was too much power and all Skippers not enough. The single fuel can is asparagus while the five can launcher onion staging.

[Jarin]

Asparagus staging seems... problematic, now with First Contract. It maximizes DV, but maximizes cost, too, with all the dropped parts.

[SRV Ron]

Asparagus staging seems... problematic, now with First Contract. It maximizes DV, but maximizes cost, too, with all the dropped parts.

Make liberal use of the SRBs on the first stage. Remember, you can limit their thrust if they are providing too much lift in their phase of the flight to extend their overall lifting performance to up to the first 10,000 meters. Still, lifting heavy payloads will be expensive.

Jool Explorer based upon another player's design