Sucking fuel out of old orbiting debris before de-orbiting

[Morgan927]

Is there a way with stock parts to get fuel out of spent boosters orbiting Kerbin, before slowing them down to de-orbit them?  Is there a way to transfer fuel between two docked ships, again with stock parts?

[stratvox]

Use the claw. You can transfer fuel through it. Procedure is: rendezvous with debris. Grab it with The Craw. Suck the fuel (if any) out of it. Point retro and burn until suborbital, and then Release the Craw and burn prograde until you aren't going to crash into Kerbin, and then set up the next rendezvous.

[Jarin]

Also, if you're just askig for the fuel-transfer interface, you can bring up and "pin" the fuel display for each tank by clicking the upper-right corner box of the info panel. Once both tanks have their panels open, you should see "in/out" buttons by the tank content readouts, allowing you to transfer.

[Snark]

5 hours ago, Morgan927 said:

get fuel out of spent boosters

...out of curiosity, why do your spent boosters have fuel in them?

In my own gameplay, nothing's "spent" until I've used it up.  If it still had fuel in it, I wouldn't have jettisoned it in the first place. 

 

[Superfluous J]

4 minutes ago, Snark said:

...out of curiosity, why do your spent boosters have fuel in them?

In my own gameplay, nothing's "spent" until I've used it up.  If it still had fuel in it, I wouldn't have jettisoned it in the first place. 

 

Back in the dark days before I used KER, I frequently used less fuel than expected and realized on return to Kerbin that I'd be able to deorbit without the aid of sometimes an entire stage of rockets and fuel. Crashing that into the ocean seemed a huge waste to me.

Back then, we didn't have the Claw so SOP for me was all stages that had any chance to ever reach orbit had a docking port on them somewhere, so I could fetch the fuel later.

These days, with KER's help, I don't have that problem. But I could easily see others having it.

[Snark]

1 minute ago, 5thHorseman said:

Crashing that into the ocean seemed a huge waste to me.

Ah, okay, makes sense.  Doesn't come up for me because, 1. I tend to engineer my missions pretty close to the bone, so they don't have a lot left when they come back, and 2. lofting rockets is so cheap relative to income from contracts and such that I simply can't be bothered with that sort of recovery, so I would have just let the leftovers burn, in that case.

[Morgan927]

37 minutes ago, Snark said:

...out of curiosity, why do your spent boosters have fuel in them?

In my own gameplay, nothing's "spent" until I've used it up.  If it still had fuel in it, I wouldn't have jettisoned it in the first place. 

 

Well, there were times when I accidentally staged when I meant to throttle up, and sometimes, I had left over before re-entry, so I left it up there.  I also want to bring fuel up in stages (pun intended) for long flights.

[FloppyRocket]

If I can, I'd like to ask a clarifying question. I'm playing stock Career mode, and am just learning my way around.

The R&D center info on the AGU (Claw) says "No Fuel Crossfeed". Yet this thread says you can use it to transfer fuel. This puzzles me.

I have a rescue contract MK1 pod stranded in an elongated orbit around Kerbin (out of fuel, out of RCS, but oh so close to home). Kerbeth would like to get home soon, it's been a long trip, what with being stranded around the Mun for quite some time. I haven't unlocked the AGU in the tech tree yet. Before I earn more science and then spend it to unlock the AGU, I'd like to know if I can put it on a ship and fly it up to dump some fuel into the empty rescue ship.

I only need about 10 m/s delta-v in order to get into a reentry trajectory. I realize there are other options besides refuelling - but I've never been able to get out and push successfully. I could use the AGU and apply the necessary DV directly. But I'm really curious about this AGU-enabled fuel transfer question.

Thanks for your help.

[Kryxal]

Crossfeed isn't transfer, I guess ... crossfeed is using the fuel from one side to power an engine on the other side.  Mind you, docking ports set to disable crossfeed DO block transfer as well...

[paulprogart]

15 hours ago, FloppyRocket said:

The R&D center info on the AGU (Claw) says "No Fuel Crossfeed". Yet this thread says you can use it to transfer fuel. This puzzles me.

5 hours ago, Kryxal said:

Crossfeed isn't transfer, I guess ... crossfeed is using the fuel from one side to power an engine on the other side.  Mind you, docking ports set to disable crossfeed DO block transfer as well...

Depends on your difficulty settings.  On Normal difficulty transfer does not obey crossfeed rules (i.e. you can always transfer even if crossfeed is disabled), but there is a setting to make it do so.  So I suspect given the No Crossfeed caution that the AGU transfer solution only works when the setting is turned off.  Of course the setting can always be temporarily turned off for this scenario, if you want to consider it valid, which depends on your own personal taste.

[FloppyRocket]

12 hours ago, Kryxal said:

Crossfeed isn't transfer, I guess ... crossfeed is using the fuel from one side to power an engine on the other side.  Mind you, docking ports set to disable crossfeed DO block transfer as well...

 

6 hours ago, paulprogart said:

Depends on your difficulty settings.  On Normal difficulty transfer does not obey crossfeed rules (i.e. you can always transfer even if crossfeed is disabled), but there is a setting to make it do so.  So I suspect given the No Crossfeed caution that the AGU transfer solution only works when the setting is turned off.  Of course the setting can always be temporarily turned off for this scenario, if you want to consider it valid, which depends on your own personal taste.

Thanks much!

[Blaarkies]

On 3/15/2017 at 2:38 AM, Snark said:

...out of curiosity, why do your spent boosters have fuel in them?

In my own gameplay, nothing's "spent" until I've used it up.  If it still had fuel in it, I wouldn't have jettisoned it in the first place. 

THIS^ 

That is why we get to Mun landings, with the Saturn 1B stage still connected, trying to land with that attached because there is still fuel in it. Don't know about you but I did that too many times when i started out...and fuel isn't even that precious