Orbital Rendezvous Assistant For docking to my Space Station & Refueling depot?

[rhn94]

Im building a space station using a bunch of mods. (e.g.

I'm more of a building guy and less of a flying guy so i suck at orbital rendezvous

Is there a plugin/mod like MechJeb to help me get very close to another ship so that i can dock to it?

I need to get within a few hundred meters and i can take on the task of docking from there.

If you guys want to see my station here it is.

[trollmylove]

the orda mod has a rendezvous auto pilot but it's immensely complicated

[Nibb31]

ORDA has a teleport to target function that puts you at 500m of the target (without using any fuel, so I guess it can be considered a bit of a cheat). However, the feature is broken in 0.17, so you have to wait for the next version.

[sal_vager]

I think rhn94 wants something that will help with getting to the station, not a tool to dock once you are there.

I remember Kosmo-not made a table that helped with orbital rendezvous, it told you when to burn to correct your orbit so you could put yourself in a higher or lower orbit in order to intercept/be intercepted by your target.

I'll see if I can find it.

Edit: Found it!

Edited October 12, 2012 by sal_vager

[Richy teh space man]

Why not just use mechjeb to get close..?

[rhn94]

MechJeb doesn't have that kind of an option

[KAO]

it has a rendezvous module, it has more than enough functions for you to get close to your target ship

or you could just learn basic rendezvous mechanics, it's extremely easy

[rhn94]

Teach me. I tried looking at the chart linked to by sal_vager but it doesn't explain how to to intercept spaceships in the same orbits.

KAO, the MechJeb module doesn't do anything, it only gives information. Again, im more of a building kind of guy, not the 'up to the challenge' guy, and there is nothing that gets my cargo to within about 500 metres or so to the space station at which point i can take it from there and dock it. If MechJeb can even point me towards the right direction, i would appreciate that.

And where can i learn basic rendezvous mechanic?

[rhn94]

Alright Guys. I just used MechJeb's "Time Launch to Rendezvous" feature

Edit:Which doesn't freaking even work...

Edited October 13, 2012 by rhn94

[Richy teh space man]

I use mechjeb for rendezvous, firstly get into a similar kind of orbit, go inside of your targets orbit to overtake, outside of it for them to overtake, then once close select rendezvous target in mechjeb, then use smart console to match relative velocities, then target it and burn towards it, repeat last two steps as necessary

[Nibb31]

MechJeb's time to launch rendezvous feature records the previous launch that used the Ascent Computer. Therefore it only works with 2 identical rockets launched to the same altitude.

There are many guides that explain how to do a rendezvous. Here is my shameless auto-quote:

First of all, make sur that your target craft is on a nice stable circular orbit. This makes this much easier the first time. Use the Orbital Operations AP, PE and CIRC buttons to achieve that.

There are 3 things to rendez-vous:

- Altitude: Well, you need to have pretty much mastered circular orbits and changing altitude.

- Inclination: Look at the map, wait until you get to the intersection of both orbits and burn normal or antinormal (NORM+ or NORM- on MechJeb).

- Period: The other ship is either before you or after you on the orbit. To catch up, lower your orbit. To slow down, raise your orbit. As you get closer, you need to reduce the altitude difference.

With a bit of practice, this will get you within 5km. At that distance, forget about orbits, and use RCS for the final approach.

I don't use the rendezvous tools in the MechJeb, because they are confusing. Especially do not use the TGT+ button, because that just points you at the target and you lose any perception of how you are moving relative to the target (whether you are above it or below it). I find it easier to maintain a PROGRADE attitude and thrust X, Y and Z to approach it.

[TouhouTorpedo]

As long as you can get moderately close, ORDA can actually do the entire procedure for you.

- have a docking computer on your spacecraft, and ideally put one on the spacecraft you want to dock with.

- if the spacecraft being docked to has a computer, turn ORDA ON, set ATT then click either VP, VN, RP, RN, which one actualy doesn't matter. This just forces your station/spacecract to hold a direction.

- go to the spacecraft you are approaching with, now turn ORDA ON, under tgt select your docking port, the station you want to dock with, and click the port you want to dock with. If the ports on the station are not showing yet, you aren't close enough. get closer first.

- Now assuming you have that part done, click DOCK. now click AUTO.

- there is a button along the bottom that brings up all current settings, click that. (none of those buttons take over your ship, so dont be worried which it was...)

- Now if you have a small ship, leave them as is, and engage the autopilot. If you have a big ship, edit those values to -half- their current and then engage. I say this because on large ships the RCS use is excessive if these values are too high.

It should do everything by itself from there on.

------------

If you're having trouble approaching close enough to do auto, heres my advice -

- get your spacecraft orbit about the same size as the station orbit.

- Now look at the angles. the orbits make through each other. at some point, unless they are already aligned, they will cross over. If your ship goes north after passing the cross over, you will have to thrust southward at the crossover. Vice versa otherwise.

- If you are behind the station, make your orbit slightly lower than the station, then you will slowly catch up with it in timewarp. Are you ahead? go slightly higher, or wait to go all the way around in a lower orbit. up to you.

- When within around 10 km, You should be able to thrust straight toward the spacecraft you want to meet up with to get closer. At this point you should definately be able to engage ORDA.

Now the last step is pretty rough, I never really think much about that part. But I beleive thats about right.

[rhn94]

ORDA is buggy as s*** .. it all slows my program down because i have close to 300 parts .. I tried docking but i was always zipping by my targets by about 300 m/s and 400 meters .. i don't know how to intercept with the difference of the ships being docked very low

[TouhouTorpedo]

ORDA is buggy as s*** .. it all slows my program down because i have close to 300 parts .. I tried docking but i was always zipping by my targets by about 300 m/s and 400 meters .. i don't know how to intercept with the difference of the ships being docked very low

close to 300 parts is more likely whats slowing your computer down so much. Also if thats how big your rocket is, ORDA doesn't use the engine, just the RCS. if the RCS is off, it'll do nothing. also, RCS won't be able to make a difference of 300m/s. You'll need to get the velocity relatively close first, or add a lot lot more RCS blocks.

[Martonaut]

I tried looking at the chart linked to by sal_vager but it doesn't explain how to to intercept spaceships in the same orbits.

welll thats becouse you cant intercept a ship that is at your same orbit, you need to be on a lower or higer orbit, I now do rendezvous by eye, but i learnd with the table that was linked, and using mechjeb,

at 300 m from the other ship its easy, the thing its getting there. my advice, park on a lower orbit, quicksave, try using table, if you fail, quick load and adjust.

also, your ships looks huge, good luck docking that monsters, even if you get in range, i think lag will kill you. you need presition movments for docking, with 2 300 part ships, well ... ill give you an award or steal your pc.

[rhn94]

well i am running an i7 2600 with 2 gtx 570s and 8 gb of ram. Obviously the game not being optimized is a factor in this. Im just gonna wait till the 0.17.1 update where they actually optimize the game and till someone does a far better version of the orda docking computer or something similar to get ships close enough to each other with a small difference in their velocities. Only the main station is 300 parts, but with the other parts i've already designed, it will collectively probably have about a thousand parts or so. Soo yeah it's a mammoth thing.

[rhn94]

This guy somehow managed it. >

http://i47.tinypic.com/169fac8.jpg

- teutoburg1 on the forums.

[TouhouTorpedo]

Ideally if you want to dock something that big, you need to get your relative velocities to zero first, and get to about 500-300m from the docking port you want to attach to while at least being on the correct side (not in alignment) ORDA does have some kind of system for this, but If I'm honest I dont understand it yet. You'd probably do well to ask questions in the ORDA thread in regards to special features - which I'm certain you will need for what you want to do.

If you're trying to use AUTO with that many parts, you are going to have to use significantly smaller values in the settings pane I mentioned. If the values are too high large spacecraft tend to just drift away.

Also are you using standard RCS blocks? If you are, I'm not suprised something that big keeps just flying on. You'll definately need a mod for bigger RCS units.

[Temstar]

It's not ORDA that slows your computer down. Once you are within I think about 2km of the target KSP will turn physics calculation on for the other ship, thus dramatically increase the number of part is has to run through the physics engine per frame. Even a top PC today can only run about 500 parts before the game becomes a slide show. So the trick is to reduce number of parts even at the cost of efficiency.

[Martonaut]

So here is a tip for lag and big stations, I just docked a refuel ship to my orbiting 300 part ship. The mission was a fail. I can't transfer fuel, Idk if it was the design or orda is broken, but anyway..

here is what I did.

The ship "mothers" is orbiting around 250 km, I made orbit at 150 km , align planes and rendezvous (quick load/save ftw) . I made it around 3km of the ship and from there just approach using my main engines, around 400 m I fight the lag to kill my relative velocity as much as possible (IM not using mechjeb so its hard to tell), then select my target on orda, go to the "mamaship" and set it on attitude so its stable, went back to the other ship and set the docking to auto, I turn rsc on and then switch to the mamaship again, this is cheating cuz the other ships stills does the "approach" but not using the rsc fuel or doing the animations, it eventually stood still near the mamaship, but it was "stuck" so I switch back to it, and it was on "orienting" , turn rsc on and let it orient, when it starts the approach I switch to the mamaship again, it will again do the approach using no rcs fuel, eventually it will get really close, and if I do nothing it aborts cuz it has an alignment error and goes back again to 400m, so I let it approach and when its really close switch to it again, let it approach and before it aborts I hit attitude so it wont push me back , and it docks.. All the maneuver are done by the orda auto pilot, and he don't have a problem with lag.

[Rokker]

Alright Guys. I just used MechJeb's "Time Launch to Rendezvous" feature

Edit:Which doesn't freaking even work...

did you use it properly? meaning did you launch once, restart and then do rendevous so that ascent will know how long it takes to reach altitude?

[Rokker]

guys i dont think we are going to get anywhere with this until someone breaks out the handy dandy orbital mechanics lesson book

[rhn94]

Enlighten me