Successfully launched Two Rockets Simultaneously with MechJeb

[Blaylock1988]

I was too lazy to make a bunch of trips, so I decided to do everything in one, jebediah style.

The video is of me launching two Karmony III parts for my space station. Using the trick I discovered using Mechjeb on 2 ships at the same time to make super easy docking, I decided to try something a little more adventurous. It took a few tries but I finally got it all in one take, uncut and unedited. I managed to keep them from drifting further than 2.5km apart so they stayed in real-time physics simulation the entire time.

After launching into space I docked both ships together for easier rendezvous to my space station.

Edited June 5, 2013 by Blaylock1988

[paleorob]

I think the scene were they bump together at the start would actually mean instant death.

[Blaylock1988]

I think the scene were they bump together at the start would actually mean instant death.

I also feared that as well, I was surprised that they came unscathed. The lower ship probably took some damage from the exhaust, but I didn't check the report to verify this.

[rodion_herrera]

I just realized by reading this thread, that probably, it's not docking that actually is difficult for some people--it's actually rendezvous.

[Blaylock1988]

I just realized by reading this thread, that probably, it's not docking that actually is difficult for some people--it's actually rendezvous.

I am interested, what was it about this thread that led you to that conclusion?

[rodion_herrera]

I am interested, what was it about this thread that led you to that conclusion?

Well you mentioned that you tried this technique because you wanted an "easier" rendezvous. Now looking back at older "I'm having difficulty in docking..." and its contents made me link your thread to those links, esp. your mention of "easier" rendezvous and realized that, some people might actually be having difficulty in the rendezvous part, to the point that if they do indeed make it to rendezvous (i.e. 2-5 kilometers apart), they have spent an agonizingly long time trying to get to that situation, that the actual act of docking itself becomes more difficult that it actually is. So yes, if people adapt your method, perhaps they'd find docking "easier" but mainly because they "skipped" the rendezvous procedure which *perhaps* they had difficulty with. So I want to rephrase my initial statement--I didn't imply that your entire thread made me think of it, it's your thread PLUS some earlier posts about the matter, that led me to this speculative conclusion.

[Blaylock1988]

Well you mentioned that you tried this technique because you wanted an "easier" rendezvous. Now looking back at older "I'm having difficulty in docking..." and its contents made me link your thread to those links, esp. your mention of "easier" rendezvous and realized that, some people might actually be having difficulty in the rendezvous part, to the point that if they do indeed make it to rendezvous (i.e. 2-5 kilometers apart), they have spent an agonizingly long time trying to get to that situation, that the actual act of docking itself becomes more difficult that it actually is. So yes, if people adapt your method, perhaps they'd find docking "easier" but mainly because they "skipped" the rendezvous procedure which *perhaps* they had difficulty with. So I want to rephrase my initial statement--I didn't imply that your entire thread made me think of it, it's your thread PLUS some earlier posts about the matter, that led me to this speculative conclusion.

Ah. The reason why I tried this was purely to see if it could even be done. Rendezvous and docking 100% manually is no problem for me personally. I am terrible at figuring out the phase angle to launch though, so I always bring a couple hundred extra dV for hohmann transfers for rendezvous, and a little RCS for proximity operations. When I mentioned easier rendezvous to my station, I meant that I can rendezvous them in one trip instead of doing both separately.

The maneuver node system is probably the single most useful tool for rendezvous. I remember back before they added it, It took me forever to do a rendezvous, but that was also before official docking nodes were added too. lol!

Edited June 5, 2013 by Blaylock1988

[rodion_herrera]

Ah. The reason why I tried this was purely to see if it could even be done. Rendezvous and docking 100% manually is no problem for me personally. I am terrible at figuring out the phase angle to launch though, so I always bring a couple hundred extra dV for hohmann transfers for rendezvous, and a little RCS for proximity operations.

The maneuver node system is probably the single most useful tool for rendezvous. I remember back before they added it, It took me forever to do a rendezvous, but that was also before official docking nodes were added too. lol!

I wasn't implying you couldn't do it It just dawned on me that perhaps, some people (and I said some, not even "most" hehe) actually have more difficult in the rendezvous part compared to the docking part. Sorry if you felt that it was my intent, really not intended. In fact, I want to congratulate you on discovering this method--it's really a feat

[Blaylock1988]

No need to apologize! I kinda want to try another video using this method, but for landing! Bring 2 ships down from orbit and land next to each other at KSC...oh man that sounds difficult! Maybe I will try that on Thursday...

[Moon Goddess]

I just realized by reading this thread, that probably, it's not docking that actually is difficult for some people--it's actually rendezvous.

I noticed that in a thread where someone posted that they had trouble docking and everyone gave suggestions and they mentioned that it didn't work but kinda danced around the fact they wern't rendezvous.

I know I had a lot of trouble with rendezvous at first, then one day it clicked and I can do it like a charm. I'm only now learning how to dock without mechjeb help cuz I just learned how wrong I've been putting my rcs.

[Comrade Jenkens]

Two ships flying side by side in KSP is kind of surreal Pretty neat trick!!

[thestookem]

Very interesting, I must try this now.

[Pleborian]

lol reminds me of something I saw a little while back:

http://www.youtube.com/watch?v=TBSU4YHemh8

[Blaylock1988]

lol reminds me of something I saw a little while back:

http://www.youtube.com/watch?v=TBSU4YHemh8

Oh WOW! I didn't know someone else had tried this, and with 3 ships! I need to step up my game.

I just subscribed btw.

Edited June 6, 2013 by Blaylock1988

[Splode]

This is fantastic, I wasn't aware that you could actually do this.

[Dedjal]

As mentioned earlier, getting the two ships lined up for docking is harder for me than the actual docking process. Kudos for those who has no problem with it it. And to OP, impressive launch! Nasa should copy it, haha.

[Pontiac]

I'm extremely impressed. VERY cool job! So I'm assuming MechJeb has to be on all ships involved?

[Mihara]

I knew 1.9.8 MechJeb could do it, but wasn't sure about 2.0. Thanks for confirming that.

I wonder, is it possible to get MechJeb to point ships in different directions upon disconnect by strategically arranging their probe cores. Sure, they'll shut down the moment they go out of physics distance, but physics distance can be extended, and this could actually be useful...

[Sephta]

I don't think it is possible with an autopilot like docking or ascend... you only have one set of values stored for them.

I did try the smart A.S.S. however and it seems you can have different sets there for two ships. Had one on target/target+ and the other one on kill rotation and it worked.

[Mihara]

I don't think it is possible with an autopilot like docking or ascend... you only have one set of values stored for them.

One set of values, multiple sets of core orientations.

MechJeb assumes that the thrust vector is always parallel the probe core orientation. (One of the lessons learned when building a VTOL rover with main engine pointing backwards -- if you don't switch orientation by switching the controlling part, MechJeb won't notice and will happily destroy your ship when you attempt to use translatron to land perpendicularly to your usual motion vector) Suppose I have three identical ships connected in parallel. One in the middle has the probe core up top, while the other two have probe cores attached onto the sides. I punch in a maneuver node, start execution and separate.

The middle one will continue on, but the side ones, while still attempting to continue executing the maneuver node, will thrust perpendicularly to their orientation vector and will spin. What I'm wondering is whether it's possible to get them to fan out instead.

[bonyetty]

Ha ha I just landed two crew pods with chutes by constantly switching between pods and thought that was pretty good. But nothing like twinor even triple launches. Super mad guys. I'm off to give it a go. Haven't watched the videos so should be a good few hours of game play for me to get it working. Very tempted to look first though.

Thanks for the thread Blaylock1988.

[Blaylock1988]

I just spent about 20 minutes looking for this thread, finally found that it was moved lol.

I am glad that you guys liked the video! I am going to try to do something like what Mihara mentioned, but I want to figure out of there is a way to orient it in a way with mechjeb to make a missile cancel out its relative velocity to a target in all directions except for forward. This would enable highly accurate tracking fire-and-forget missiles, instead of dumbfire rockets.

Something I would love to see is a programmable computer similar to Expression 2 from HL2 Garry's mod (uses code similar to C+). You can program the chip with mechjeb functions and conditions and timing with variable inputs so that it will execute the code once activated. This would allow automatic orbital construction, automatic refuelling, executing multiple operations on multiple ships at the same time (or preprogrammed times), and of course, very smart missiles/weapons.