cant get back to my station

[Brycesv1]

getting into orbit i can do. re-entry i can do. atmosphereic flight i can do... but i cant for the life of me get back to my space station. i started building one, it has a near circular orbit at 350km. my problem is that i cant ever get close to the dam thing when i try to get back into orbit with more modules. how would i set up the launch MFD to reach it? or is there something else that i should be doing entirely? im completely clueless here

while im here... im using the space station building blocks and the XR-5 to bring them up but the station begins to rotate as i try to build it. is there anything i can do to stop this rotation? i was thinking maybe theres a RCS module i could bring up with the XR-5 to stabalize it

 

[Tommy]

Have you tried going to the ISS? It's the same proceedure. You can use LaunchMFD to help choose a launch time and heading, otherwise you'll have to calculate the launch heading yourself. Check the DGIV (from Dan's Orbiter Page) manual for the formula. launch about 300 to 360 seconds before AlignPlanesMFD shows you crossing the node.

Establish a parking orbit of 200k to 250k altitude. Align planes, sync, and rendevous. Check out the "Go Play in Space" tutorial for more in-depth proceedures.

 

[Nemoricus]

If you're docked to the station, you can simply use the XR5's thrusters to stop the rotation. The XR5 is meant to launch and maneuver with up to 432 metric tons of cargo. It's very likely that your station comes nowhere near that much mass. At least, not yet. In this case, the XR5's RCS is most definitely boss.

By the way, post some pictures of your station as you work on it. Eyecandy is always nice.

 

[Brycesv1]

roger that. will do. i think it would look better if it didnt have a large ship docked to it for RCS. there must be a way to stabalize it... i think theres an attitude control module in the building block package. ill have to edit that into the scenario and bring it up next

 

[Brycesv1]

ok i put most of it together. had to start from scratch since something happened to my save file still not sure how to get back to it once i de-orbit myself but for now this is what i got

 

[Nemoricus]

It's a cute little thing.

On rotation: Crazy spinning occurs with vessels if they dock and are not perfectly aligned. The angular momentum generated by the sudden twist is transferred to the whole stack. The only way to prevent this is to have a large mass attached to it to soak excess angular momentum.

Also, gravity gradient torque causes spinning, but is a much slower effect.

On getting back to your station: This lets you calculate your launch heading: http://orbithangar.com/searchid.php?ID=2464

After that you can launch when the path of your station passes over your position on the ground. Open up Map MFD, set your target to a component of your station, and wait for the path to coincide with your position.

After getting in orbit, use Align Planes MFD to align your plane with that of your station. From there, I like to use TransX (see flytandem's excellent tutorial on the subject). However, you can pick your own method.

 

[Brycesv1]

ok. its orbit started passing over me so i decided to launch ahead of it a little bit and thought id just take a wider orbit to let it catch up. somehow i managed to go so fast whil i was low that i overtook it and am now MUCH farther than i expected to be. heres a screenshot of the data i think u guys will need. any ideas on how to fix it so i intercept it at the right time? iv never used the orbit sync things except a long time ago to impact the moon so assume that i have no idea what im doing

EDIT: would it be possible to use the dragonfly or shuttle-a permanently docked with the station to use the RCS as a means to control the rotation? i could bring fuel to the station and use that to fuel the RCS

 

[tblaxland]

The left MFD shows you have a subsurface perigee, so you will want to fix that first (you are approaching apogee so it is a good time to do that). Make your apogee higher than your station so your station will catch up to you.

Next, you have quite a large relative inclination between your orbit plane and the orbit plane of your station (0.93°). Fix that using Align Planes MFD.

Finally, refine your rendezvous with your station using Sync Orbit. There are lots of descriptions on how to do so but I recommend the one in Go Play In Space. This OrbiterWiki article also gives you a good theoretical background on what you are trying to do.

 

[Brycesv1]

yeah i was gonna wait till just before apogee before i burned to bring up the perigee

EDIT: should i bring the perigee to match the station perigee or should it be above the station so it catches up faster?

EDIT2: did orbit+ and burned and the Rinc went down to 0.33 degrees before going back up. this leads me to assume that doing what i just did isnt how im supposed to do it XD... unless its because my perigee and apogee are so much different but i dont think that would be the case.
so... instructions on how to use align planes and what to do when i know what im looking at?

 

[tblaxland]

EDIT2: did orbit+ and burned and the Rinc went down to 0.33 degrees before going back up. this leads me to assume that doing what i just did isnt how im supposed to do it XD... unless its because my perigee and apogee are so much different but i dont think that would be the case.
so... instructions on how to use align planes and what to do when i know what im looking at?

Apogee and perigee don't make any difference when aligning planes (except perhaps to reduce the required fuel for the burn, but such factors can be ignored for the time being, baby steps...). Did you do your orbit normal burn at a node (a point where the two planes cross, there are two of them on opposite sides of your orbit)? Also, did you burn in the right direction? Remember the saying: burn Anti-Normal at the Ascending Node (and therefore normal at the descending node). Orbiter.pdf and Go Play In Space both contain better instructions than I could ever write. Read both and let us know if you need further clarification after that.

 

[Ark]

Go watch that DGIV to ISS video. Makes Earth launch to station rendezvous as simple to understand as possible.

 

[tblaxland]

Go watch that DGIV to ISS video.

That would be this one here: http://www.orbiter-forum.com/showthread.php?t=2055

 

[Brycesv1]

read the go play in space and it really helped. i now know how to correct the inclination *pats self on back*

now i just have to meet up at the proper altitude. in the sync orbit MFD if i have Dtn at 0 then i should intercept at the green line correct?

---------- Post added at 03:46 AM ---------- Previous post was at 12:04 AM ----------

ok i got station rendevous down. i braught a few more modules up and a crew of 3. i also attached a dragonfly to the end for RCS and had it autopilot prograde. it should hold until i find something better. i had a question. would its RCS work better attached to the end of the station or somewhere in the middle?

 

[Urwumpe]

RCS works best if you have a long lever arm = distance to the center of gravity of the spacecraft/multimodular space station.

 

[Brycesv1]

so attach an RMS module in the center of the station and have it reach out to hold the dragonfly?

also i like the dragonfly but would the shuttle-A be a better choice for RCS?

 

[Urwumpe]

No the Dragonfly is better suited. Or you make a special RCS module for your station.

If you plan to use CMGs or reaction wheels, you should place them closer to the center because these make you rotate around their center.

 

[clickypens]

Are there CMG or reaction wheel modules available anywhere? I've always thought that my station was forever doomed never have a stable attitude.