Transfer stage running out of fuel.

[painking]

So this isn't any specific problem I'm having, but a question to get out of the way for when I do experience this problem as I'm beginning interplanetary travel.

What does one do when their transfer stage doesn't provide enough fuel? You can't just slap on more fuel, because then the launch stage has to lift more weight, which means it runs out of fuel earlier, which means your transfer stage has to start burning earlier, which means you end up using that extra fuel you brought to minimal, if any, affect.

Edited June 20, 2013 by painking

[capi3101]

Best way to overcome that is to build the ship in orbit. Launch tug, launch fuel, launch lander, dock them all together (USE SENIOR'S!!!). It's what I usually do. At least, it's what I started doing after I encountered the very phenomena you're describing first time I shot for Duna...

[Flixxbeatz]

Stick some docking ports and run refueling missions, provided that you already have an idea how to dock. For me, it's better to bring surplus fuel than running out somewhere in between and burning up reserves intended for the later parts of the mission. Also, a screenshot of your transfer stage might help.

[esinohio]

Bump the suggestions above as well as using the "map" on this forum thread. http://forum.kerbalspaceprogram.com/showthread.php/25360-Delta-V-map

If you do some more digging you can find a really nice deltav map floating about somewhere out there in internet land. Great resource for planning out those trips to the great beyond.

[Johnno]

Your transfer stage is supposed to start burning in a stable orbit, thus it shouldn't have to start 'earlier'. Simply put you have to build a rocket to take it into stable orbit. The heavier your transfer/landing/return craft/stack is the heavier of a launcher you have to build to get it into a stable orbit.

I think you're stuck in the though process of just having one lifter design and adding to it, rather than redesigning it. If you have more mass to launch then yes you need more fuel, but you also need more engines. Just adding more engines to your current design won't work, and just adding fuel won't work, but adding engines AND fuel will.

And if your transfer stage runs out of fuel it's not designed for the trip, crudely put. I'd advice you to start from the opposite end. What do you need to get home, what do you need to get off the planet you're visiting, what do you need to land, what do you need for orbital insertion, what do you need for the transfer.. Once you've got that ship built it'll be capable of the trip. Then build a launcher to take it up into stable orbit without using the payload's fuel.

If you can't launch heavy stuff then make it modular, that'll require docking and a bit of preplanning, but it's an easy way compared to struggling with launching everything in one go.

[Sirrobert]

Try adding more asperagus staged engines to your lifter.

[EndOfTheEarth]

1) What kind of engine are you using? You may be running out because of engine efficiency. Nuclear engines are the best.

2) How heavy is your payload? Weight matters in KSP, just as it does IRL. Go for the lightest possible payload.

3) Do you have a backup plan? It helps to have more than one docking port on a tug, so you can send an emergency refueling mission.

4) Are you sure you brought enough fuel to begin with? This isn't a flight to Minmus; some of these flights can take a lot of fuel. Yes, it will mean building a larger launcher.

5) Are you trying to bring everything up in one go? While this works if you're trying to send a tiny probe, it runs into problems if you're trying to send a big ship. Try a multipart ship?

For reference, this can get into orbit around anything:

Here is the ship I use for one-way lander probes for all bodies except Moho, Vall, and Tylo:

And this is how I recently got to Ike:

Notice how each of the principles of weight, engine type, and docking is applied.

[Tex_NL]

How I conquered Moho.

Moho has been my nemesis for quite some time. Getting there wasn't the problem but every time I tried, with different ship designs, I ran out of fuel only a few hundred m/s before achieving orbit. Yesterday I finally made it all the way.

I did not want to redesign the ship so during launch I did not discard my last lifting stage when it ran out. Instead I transfered fuel from the transfer stage to keep the lifting stage burning. In LKO I refueled both the transfer and lifting stage and used the lifting stage for the first leg of the journey. I made it to Moho with fuel to spare.

[Dkmdlb]

Quick and easy way to increase delta-v of first stage, useful for getting that little extra boost if you need.

Place lots of solid fuel boosters around the rocket with radial decouplers.

On launch, reduce throttle to 50% or whatever. Let the solid fuel boosters do the lifting for the first 1- to 2,000 meters. This isn't the most efficient way in terms of TWR or fuel efficiency, but it is a quick way to get the job done because you don't have to place additional fuel tanks AND engines AND fuel lines. Solid boosters are just one part rather than three or more, and you don't have to worry about getting fuel lines in the right place.