Orbital Station Construction

[Ncog Nito]

Good evening.  I was looking over a contract for an orbital station being placed in a solar orbit.  One of the requirements is 6000 units of liquid fuel aboard the station.  My question is can you add on to a station once in orbit, and if so, how is this done?  I know you can dock with a station and transfer fuel, or leave them connected, but what I am wanting to do is construct one in orbit, kind of like the ISS.  Are the docking ports used for connecting pieces or can pieces be added with out "blocking" docking ports?

[bewing]

In stock KSP, you have to use docking ports or klaws in order to add extra bits to vessels that are already in flight.

So the basic answer to your question is no, you have to block a port ... at least temporarily. Once the contract is complete, of course, you can take everything apart again.

 

[HvP]

You should also be aware that if your contract says "This must be a new station launched after accepting this contract," or similar wording, then all parts of your station must be created and launched AFTER you accept the contract. If any of the parts or tanks you dock to this station were built before you accepted the contract then it won't let you count those towards the completion of the contract.

In other words, while you may be able to use a fuel tanker that you already had in orbit, you will have to undock it again before the contract will be marked as complete -- assuming that all the requirements will be met with just the newer parts and fuel capacity remaining on the station.

Edited May 2, 2017 by HvP

[Ncog Nito]

27 minutes ago, bewing said:

In stock KSP, you have to use docking ports or klaws in order to add extra bits to vessels that are already in flight.

So the basic answer to your question is no, you have to block a port ... at least temporarily. Once the contract is complete, of course, you can take everything apart again.

 

Ok...two additional questions then:

First...klaws?

Second, if I don't use "klaws", I build the new station, put it into orbit, ferry the fuel tanks up to it, attach them via docking ports, then move them into a solar orbit? 

[Cpt Kerbalkrunch]

13 minutes ago, Ncog Nito said:

First...klaws?

He means the Advanced Grabbing Unit, aka "the klaw". Sort of an all-purpose docking unit. Very useful.

[bewing]

Klaws: (AKA Advanced Grabbing Units)

 

And yes, your plan sounds right. Just (as HvP said) make sure that each ship is new before you dock it to your new station -- or it will suddenly not  be "new" anymore.

 

[Ncog Nito]

11 minutes ago, bewing said:

Klaws: (AKA Advanced Grabbing Units)

 

And yes, your plan sounds right. Just (as HvP said) make sure that each ship is new before you dock it to your new station -- or it will suddenly not  be "new" anymore.

 

Hey @bewing, that is a neat design there!  Very ingenious use of parts.  What part on it is the Klaw?

[bewing]

27 minutes ago, Ncog Nito said:

Hey @bewing, that is a neat design there!  Very ingenious use of parts.  What part on it is the Klaw?

The ones on the ends. You should probably recognize all the others.

 

Edited May 2, 2017 by bewing

[Ncog Nito]

Thanks for the advice guys, guess i'll give it a try and see what happens.  I'll probably wait till I have the klaw tech, looks like in would probably be more convenient than using my docking ports.  One last question though, in your opinion, what would be better to use in this instance, the klaw or the docking ports?

[FullMetalMachinist]

@Ncog Nito klaw entry in the Wiki. 

[Cpt Kerbalkrunch]

2 minutes ago, Ncog Nito said:

One last question though, in your opinion, what would be better to use in this instance, the klaw or the docking ports?

Just my opinion; I think the docking ports look a lot better (especially for a space station), but the klaws are more versatile. So it would depend on which matters more to you. Docking ports have to be the same size to connect, while a klaw can connect to almost anything.

[Ncog Nito]

Thanks, @FullMetalMachinist, that gives me the knowledge I need to decide.

[HvP]

1 hour ago, Ncog Nito said:

Ok...two additional questions then:

First...klaws?

Second, if I don't use "klaws", I build the new station, put it into orbit, ferry the fuel tanks up to it, attach them via docking ports, then move them into a solar orbit? 

The Advanced Grabbing Unit is nicknamed The Klaw. It gets unlocked at the 160 research level under the "Actuators" tech node. (ninja'd)

Assembling your station by docking everything together in Kerbin orbit and then moving it to solar orbit will be much easier and less time consuming than trying to assemble it in solar orbit. Just consider that you want to distribute the weight fairly evenly on both sides of your station so that your thrust won't be off center. Engine vectoring, RCS, and reactions wheels can compensate for a little uneven weight distribution though depending on the mass involved.

I'd recommend putting those big fuel tanks inline with the engine though especially if your thrust-to-weight ratio is high. But, the bigger the docking port, the more stable the connection, and the less risk of them bending under high thrust.

Edited May 2, 2017 by HvP

[Spricigo]

1 hour ago, HvP said:

You should also be aware that if your contract says "This must be a new station launched after accepting this contract," or similar wording, then all parts of your station must be created and launched AFTER you accept the contract. If any of the parts or tanks you dock to this station were built before you accepted the contract then it won't let you count those towards the completion of the contract.

In other words, while you may be able to use a fuel tanker that you already had in orbit, you will have to undock it again before the contract will be marked as complete -- assuming that all the requirements will be met with just the newer parts and fuel capacity remaining on the station.

Actually, once you dock two crafts toghether they will get the "fabrication date" of the oldest. Refuealing with a old tank will prevent to complete the contract with your brand new station.

[HvP]

4 minutes ago, Spricigo said:

Actually, once you dock two crafts toghether they will get the "fabrication date" of the oldest. Refuealing with a old tank will prevent to complete the contract with your brand new station.

Hmm, I was under the impression that it would revert back when the old part was undocked again. Considering the time it will take to send your station out to solar orbit @Ncog Nito I would be on the safe side and be sure that you don't dock any parts older than the contract at any point in the construction.

[Ncog Nito]

Ok, another thought.  I want to put this in a solar orbit that keeps it within close proximity to Kerbin.  That way I can use it as a refueling point for missions outside Kerbin SOI.  How would I go about doing that?

[HvP]

24 minutes ago, Ncog Nito said:

Ok, another thought.  I want to put this in a solar orbit that keeps it within close proximity to Kerbin.  That way I can use it as a refueling point for missions outside Kerbin SOI.  How would I go about doing that?

While it might sound like an attractive place for a pit stop, a solar orbit really isn't very useful as a fuel station. Half of your fuel used to get anywhere in the solar system is used getting into low Kerbin orbit in the first place. Half of what's remaining is used to escape Kerbin orbit and put you on an interplanetary rendezvous. Only minor corrections are usually needed in deep space until it's time to capture into orbit around your target.

Chances are that once you try to rendezvous with a solar refueling station then you will waste more fuel trying to get to your destination because you are no longer in a good place to make a transfer orbit to your target. The best places to refuel are in Kerbin orbit to replace the fuel you used to launch through the atmosphere, and at your destination to get back (usually from a mining operation on the surface of the other planet or moon.)

A better use for the solar station in my opinion would be to slap a few high gain relay antennas on it, the biggest you can get, and move it to either a very high or very low orbit around the sun -- assuming you have enough delta-v -- so it can act as a comm-net relay. Or, use all that fuel you are bringing along and see if you can get it to one of the other planets for some huge science gains after you've completed the contract.

Edited May 2, 2017 by HvP

[Ncog Nito]

Excellent thought @HvP!  That does sound like a much better plan, thanks.

[HvP]

15 minutes ago, Ncog Nito said:

Excellent thought @HvP!  That does sound like a much better plan, thanks.

You're certainly welcome. If you're going for the relay idea just remember, things get hot near the sun, very hot, explodey hot - but the orbits are quicker and since any planet you go to later will be on the other side of the sun from Kerbin half the time then a low orbit relay has the opportunity to nearly double your typical range for remote probes. The sun will however also block a signal to your relay sometimes.

Outer planet orbits for relays are best when they are put into orbit directly around target planets themselves instead of just solar orbit and electricity from solar panels is extremely weak. Anyway, have fun experimenting.

Edited May 2, 2017 by HvP

[Ncog Nito]

One more question for you.  To move that much weight from Kerbin orbit to Solar orbit, with all that excess fuel, is a poodle engine sufficient enough, or do I need something bigger?  To the best of my knowledge it should be sufficient as I am in the vacuum of space, but I'm not a rocket scientist, pun intended.  The poodle is my primary space engine.  It has good fuel efficiency and has done a great job getting me around the Kerbin System.

[bewing]

Smaller engines do exactly the same job as the bigger engines, but they do it more efficiently (generally) and they do it much more slowly. So it depends on how much patience you have. But for only 6000 units of fuel, a poodle should still be pretty fast.

 

[Ncog Nito]

52 minutes ago, bewing said:

Smaller engines do exactly the same job as the bigger engines, but they do it more efficiently (generally) and they do it much more slowly. So it depends on how much patience you have. But for only 6000 units of fuel, a poodle should still be pretty fast.

 

 

Excellent, I will let you all know how it goes.  All of you had some valuable input, thanks for your patience, it is much appreciated.

[Ncog Nito]

Success!!! Thanks guys.  I was able to put this hunk of mass into solar orbit, even though it flopped about like a fish out of water trying to break orbit.  I figured out that a slowly accelerating to full speed greatly reduced the "wiggle".  Here's the monstrosity accelerating towards solar orbit.  Again, your help was much appreciated.

 

[maceemiller]

On 2017-5-7 at 4:32 AM, Ncog Nito said:

Success!!! Thanks guys.  I was able to put this hunk of mass into solar orbit, even though it flopped about like a fish out of water trying to break orbit.  I figured out that a slowly accelerating to full speed greatly reduced the "wiggle".  Here's the monstrosity accelerating towards solar orbit.  Again, your help was much appreciated.

 

KSP gives so much pleasure to so many Congratulations on your station....and I learned about the Klaw...never used it before but will now....so much learning everyday in this game

[Draalo]

On 7.5.2017 at 5:32 AM, Ncog Nito said:

I figured out that a slowly accelerating to full speed greatly reduced the "wiggle"

This is because of the engine gimbal.

If you go for instant 100% throttle ("Z") and you are not perfectly alligned (and you re never perfectly alligned), the gimbal tries to correct this and overshoot. Resulting in another correction in the opposide direction - and that causes the wobble.

 

Throttling up slowly with "SHIFT" makes the initial force relative weak, resulting still in wobbling but at a much lower amplitude.

 

So allways throttle up patiently if your vessel is tall and/or massive.