Docking with stock parts

[Temstar]

Well, why not?

Here is my Olympus 3 Space Station, built to dock up to three spacecrafts with the three docking arms

After many attempts, here is my LKO spacecraft successfully engaging soft dock with the station. The ship has clamped it\'s claw onto one of the station\'s docking arms.

Jumping into the station, I closed the station\'s docking claw around the spacecraft to strengthen the docking.

After both sets of claws are engaged, I then used the station\'s RCS thrusters to pin the docking arm against the spacecraft for a better grip.

Some issues with the fuel tank models, they\'re clipping into each other here.

After this I did some test on the strength of the dock, conclusion is that it\'s pretty weak. I\'m not sure if the pads on the end of the landing legs are actually solid objects, but I know at least it\'s not long or tight enough to firmly grip the smooth side of fuel tanks. The arms will prevent any lateral movement of the two ships but if there\'s movement long the length of the arms then the docking arms were unable to prevent the two ships from separating.

Next step I plan to put some bumps on the outside of docking arms with struts to provide more traction for the claws. Let\'s see if that improves things. If things work out then a Munar Orbit Rendezvous mission profile for munshot may be possible.

[Panichio]

Wow, great job! That takes a lot of flying skills to do that!

[Temstar]

From the lessons learned from today\'s orbital rendezvous test, following improvements have been made to the docking arm:

• 
  [li]Tip of the arm now uses decoupler rather than fuel tank, this is because decoupler seems to have a bulging mid section for the claws to grip onto[/li]
  [li]claws are now placed at the very top of the decoupler, improving length of the grip as well as make the legs close tighter tighter[/li]
  [li]notches are added on the arm to provide some traction for the claws to grip onto[/li]
  [li]increased number of claws per arm from four to six to increase strength[/li]
  

Hopefully we\'ll see some improvements in the firmness of the docking in my next test.

Note to devs if you\'re reading, please please make Advanced SAS work for ships not being piloted. 90% of the hard work in docking comes from trying to align the docking arms up on the same orientation. Just as you get it all lined up and ready for RCS translation the target ship will roll in some random direction forcing you to start over.

[VincentMcConnell]

Can you spoiler all of these images and change their width to 600? I don\'t want to have to wait for all of them to load and have a thread this big. I\'m sure it\'ll bug other people too.

[Capt'n Skunky]

Can you spoiler all of these images and change their width to 600? I don\'t want to have to wait for all of them to load and have a thread this big. I\'m sure it\'ll bug other people too.

Images wrapped in spoilers still download, it just makes the post easier to navigate, but yes, it would be nice if the OP would do so.

Cheers!

Capt\'n Skunky

KSP Community Manager

[Temstar]

With 0.15 out we are now able to add landing legs inverted without fooling around with karts. So I ran a quick test on docking again with a test rocket.

Here is my test ship. The aim is to grab the nearly spent rocket stage behind me with either set of legs.

So the idea here is to see how well I can dock with forward vs reverse landing legs. Immediately in VAB I noticed a difference - you can\'t get as tight of a grouping mounting legs backwards on fuel tanks or even decoupler as you can forwards. In the above picture you can see the difference. Notice how I was able to place the forward legs so far inside the decoupler that the pivot is almost flush against the decoupler wall, where as the rearward legs can only be attached onto the wall of the tank.

The rear legs are easy to test, I just have to keep the legs closed and stage. Unfortunately it turns out there\'s no grip at all on the rearward facing legs, the rocket stage immediately slips out. So it\'s onto the forward set.

After reloading I flipped the spaceship around and inched my way inside the decoupler nose first.

Success, the forward landing legs were able to firmly grip the decoupler. Wobbling the spacecraft around pivots the rocket stage in front of me without any loosening of the grip, looks like a pretty firm dock.

I then turned SAS off and the ship started rolling like a top. Even turning SAS back on was barely able to bring the ship under control. I turned SAS off again and sure enough the rolling started again. Leaving the SAS off resulted in the ship rolling faster and faster until the forces involved violently tore both ships apart.

It seems like the spent rocket stage is somehow exerting a rolling force on my spaceship without any source of acceleration, physics engine bug? I don\'t recall this happening in my earlier test docking two crewed spaceships, maybe this only happens with debris?

Next step I plan to put a large spaceship in orbit and then try to dock to its tail with a smaller spaceship to test stability. If docking is successful and there\'s no miraculous force trying to spin both ships I\'ll then try to do an orbital maneuver. If that\'s successful then I say we\'ve found a way for Apollo style Munar Orbit Rendezvous mission.

Test ship is attached for those wanting to try for themselves.

[Wyrm]

Cool beans!

And yes, I did notice that dead weight ain\'t so dead. A few times launching spacecraft, I got a mysterious tumble that had no apparent source. I think it may be connected with debris tumbling, because every time it happened, I noticed that sometime earlier in the flight, a part broke but never actually separated from the spacecraft.

This might be reporting bias, though.

[JiWint]

Why everyone finds docking and rendezvous very hard? I did it successfully on the first time

[RogueMason]

Mother of necro

Unless of course that was your evil intention. Seriously, don't post in threads this old, they're way out of date. This one harks back to 0.14 or 0.15 of the game, a time when docking and rendezvous was incredibly difficult without mods.

[Temstar]

Oh wow, someone dug that up?

I still remember doing that "docking", took me something like 2 hours to achieve that. Aside from no maneuver node and closest approach indicators, back than KSP didn't track ASAS status when you switch crafts so those two would constantly drift out of alignment so I had to constantly switch between the two to keep them pointed in the right orientation.

The game sure has come a long way since then,that old docking test to today's KSP feels just like looking back at the old Gemini flights with our modern eyes

[Brotoro]

Wow... A real blast from the past. I suppose this thread will just confuse the new people, but I enjoyed seeing it. Kudos on the ancient docking, Temstar.

[karolus10]

Necro-posting in it's finest moment... As You can see, You can do (nearly) everything in KSP, even if this wasn't implemented yet .

[Scotius]

It wasn't docking. It was grabbing Awesome pictures, and a great proof that when there is will, there is way.

[Kerbal01]

Karolus, lock this.

[DaRocketCat]

No, this should stay open so that we can reminisce about the "good ol' times".

[Temstar]

I think it was Harvester who said something along the lines of "the parts and capability of KSP over the versions tend to reflect the natural progression of real space programs" and that his is what he want to replicate with career mode. Since I've always been a docking advocate I got to see the development in this area first hand. Let's see what happened over the versions and how it mirrors real life:

In the beginning - there was no persistence or tracking station, so you're stuck with just the active flight you're running. The closet thing to rendezvous you could do in those bad old days where to just turn around the capsule after separation from the booster rocket and track the spent booster behind you. This is exactly what happened during NASA's Mercury program. The Mercury spacecraft was primitive and didn't have the ability to translate, only row pitch and yaw. So one of the thing that Mercury flights did was spin the spacecraft around and look at the booster behind it.

Version 0.11 - RCS system introduced to allow translation control, spacecraft control system greatly improved with the introduction of ASAS and orbital view. This mirrors the Gemini 3 flight with the introduction of a much improved spacecraft with both translation and rotation control, paving the way for fine manoeuvres on orbit

Version 0.14 - major break through with introduction of spacecraft persistence and tracking station, allowing multiple flights at once, thus first opening up the theoretical possibility of rendezvous. However there is very little experience with rendezvous in the community at that time and little guide available, so most players are in the dark as to how to do this. This mirror's the situation on Gemini 4 where the spacecraft attempted to rendezvous with its spent booster but failed because simply pointing the nose at the target and thrusting didn't work. Like KSP players around this time NASA staff have not worked out all the nuances of orbital mechanics yet.

Version 0.14.4 - when this thread was first posted. No technical improvement in the game but people have played with persistence long enough that the first rendezvous guide started showing up on youtube. Rendezvous was still very difficult because there was no select target or closest approach. And in any case where you get there there was no way to dock. Yours truly cut his teeth on rendezvous around this time and as you can see tried to come up with primitive ways to connect the spacecrafts. This mirrors the situation with the Gemini 6A and Gemini 7 rendezvous where two spacecrafts launched separately where able to meet up to as close as 30cm. However lack of docking port mean that Gemini 6A and Gemini 7 couldn't actually physically join as one craft.

Even without working docking ports, the fact that I managed to briefly get two spacecrafts to grab each other fired my imagination and filled my head with ideas of propellant depots and tanker rockets and colossal interplanetary motherships:

Version 0.17 - around this time the first docking mods became available. I remember back there the two were ORDA and warp claws, each with their strength and weaknesses. They didn't actually merge two crafts like modern docking, but rather the parts would pull on each other with massive force once they are close enough. Me, being Dr Rendezvous was busy promoting the possibilities opened up by docking and came up with a system that used both ORDA and warp claws at the same time on the same craft and performed the first big "mothership style" interplanetary mission with my Duna/Ike double landing and return:

This mirrors Gemini 10, where primitive docking ports where first introduced and used to dock Gemini 10 with an Agena Target Vehicle. Test shows that it's possible to use engines on one spacecraft to boost the combination to other orbits. Thereby paving the way for Apollo's lunar orbit rendezvous mission plan.

Version 0.18 - stock docking, much joy all around from the community. Stock docking turns out to be much more reliable than the mods and all the rage at the time was Apollo-style lunar landing mission. I was also caught up and shared one such craft:

This mirrors the Apollo fights, where docking became mature technology and allowed much more delta-V efficient mission profiles.

Version 0.19 - rovers where introduced, introducing theoretical possibility of docking on the surface of a body. At the time I was working on docking with multiple ports at once to allow heavy duty space construction which resulted in this:

Orbital Propellant Depot Olympus II. Of course this then become obsolete with the release of large docking port in 0.20. But I wasn't too bothered since wide spread heavy docking meant the explosion of heavy construction in orbit.

This mirrors the development of modular space stations such as Mir and ISS.

Version 0.21 - After a long break I came back to KSP to continue to work on the modular surface base idea. All the tricks have been worked out and it's almost ready to be shared:

Real life space program haven't advanced to surface base construction yet

Edited September 13, 2013 by Temstar

[LameLefty]

This mirrors Gemini 10, where primitive docking ports where first introduced and used to dock Gemini 10 with an Agena Target Vehicle. Test shows that it's possible to use engines on one spacecraft to boost the combination to other orbits. Thereby paving the way for Apollo's lunar orbit rendezvous mission plan.

Great post down KSP History Lane, but minor correction on the real-world history. The first docking was Gemini 8 to the Agena Target Vehicle (Neil Armstrong, commanding, and David Scott, pilot). There was a Gemini RCS malfunction almost immediately after docking and the mission had to be aborted after an uncontrollable roll developed. Armstrong saved the lives of himself and Scott by thinking quickly and making the right calls to save the spacecraft using the re-entry RCS system.

Anyway, otherwise I loved seeing this "ancient" thread come to life, necro or not.

[sporkafife]

Whoah!! I came on this thread thinking someone was having a problem with the stock docking adapters, only to find myself in the holy-grail of Necros! I remember having to use landing legs to save stranded spacecraft... those were the days

[Kasuha]

There are no docking ports in Demo so some people might still use these ideas.

[DisarmingBaton5]

I kinda don't want this thread to be locked, despite the necropost. I remember watching people fly formation in the forums in 0.17 (ignore the join date, I joined late) and being astonished that they accomplished rendezvous, and then proceeded to fly in formation.

[Skorpychan]

Oh, wow. Only with KSP does a necropost turn into a history lesson.

Also, I think I'm going to use the landing-legs technique to save a spacecraft of mine that's stranded without fuel, power, and docking ports, if just jetpacking the kerbals over doesn't work.

[RoboRay]

I remember watching people fly formation in the forums in 0.17 and being astonished that they accomplished rendezvous, and then proceeded to fly in formation.

Well, it was a lot harder to rendezvous before the craft targeting system and the closest point of approach markers on the Map screen. If we had had docking ports back then, this would have been my first successful docking.

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I'm glad I did it in 0.17 simply for the feeling of accomplishment, but I sure do appreciate the tools we have now.

[Comrade Jenkens]

OMG!!! This is from the age of the dinosaurs!!