General Question Undocking Inertia - Orbiter-Forum

KuatYards · 07-18-2012, 10:05 PM

I am trying to build a station in LEO with Station Building Blocks 4.1 and the XR5 with SBB Cargo configs, when undocking the dragonfly from the Station to manuver another piece from the Vanguard to the station, both the dragonfly and the station start flying in opposite directions, is there any way to stop this for at least one of the vessels, or do i just have to deal with it?

**garyw** · 07-18-2012, 10:20 PM

Why not just null out the relative velocity difference with translation thrusters or

Attitude MFD V3.2

?

**icedown** · 07-19-2012, 01:19 AM

When I'm doing this, I usually deploy the first piece from the cargo hold and dock the XR5 to it, then I've got a solid base to start putting it together from. I've found the URMS very hand also, and it fits nicely in the XR5's bay.

palebluevoice · 07-19-2012, 02:40 AM

Undocking inherently MUST make the two spacecraft fly in opposite directions. You can unlatch the docks, unscrew them; etc., but it still won't seperate them.

"Objects in motion will stay in motion unless otherwise acted upon"
If they're relative speed is one inch per second, they will seperate at one inch per second for all eternity(or until they crash into each other after a couple thousand years when the dragonfly hits the ISS in the butt).

Therefore, anytime you undock, you must take manuevers to correct the reletive speed of the spacecraft; as Gary said, the attitude MFD has a mode that allows you to cancel relative velocity; alternatively, you could just use the dock MFD to display the relative the velocity.

Happy space travel!

**C3PO** · 07-19-2012, 11:12 AM

Quote:

Originally Posted by palebluevoice

Therefore, anytime you undock, you must take manuevers to correct the reletive speed of the spacecraft; as Gary said, the attitude MFD has a mode that allows you to cancel relative velocity; alternatively, you could just use the dock MFD to display the relative the velocity.

The problem is that when you release a module from DF, the module "inherits" an "undocking velocity" relative to the XR5. Even if you null the relative speed between the module and the XR5, they will begin to drift as soon you jump back to the DF. Singleplayer formation flying with 3 vessels is not easy.

IMHO icedown's solution is the way to go. It's sort of the same way the ISS was built, but the RMS is replaced with a Dragonfly. Transfer the first module to the XR5 docking port, and the problem is solved.

KuatYards · 07-20-2012, 12:34 AM

Thanks for the help, i tried to stabilize maually from the DF... that failed... thanks icedown, when i read that i went

should have thought of that... thanks

**Cairan** · 07-20-2012, 01:44 AM

Hmm, which brings us to the idea of having a station keeping module or script so that unfocused vessels in the vicinity of a given target can autonomously do station keeping (ie. null out relative velocities by RCS)...

Zatnikitelman · 07-20-2012, 02:07 AM

Quote:

Originally Posted by Cairan

Hmm, which brings us to the idea of having a station keeping module or script so that unfocused vessels in the vicinity of a given target can autonomously do station keeping (ie. null out relative velocities by RCS)...

There was an addon that did that, I want to say the name was Intermod2, but it could maintain a relative position.

**icedown** · 07-20-2012, 02:23 AM

DG lifeboat with remote control killrot is what I use to stabilize it before I dock back up. It's much easier to hit a spinning station with the DG than my XR5.

07-18-2012, 10:05 PM	#1
KuatYards Ejection Seat Tester	Undocking Inertia I am trying to build a station in LEO with Station Building Blocks 4.1 and the XR5 with SBB Cargo configs, when undocking the dragonfly from the Station to manuver another piece from the Vanguard to the station, both the dragonfly and the station start flying in opposite directions, is there any way to stop this for at least one of the vessels, or do i just have to deal with it?

07-18-2012, 10:20 PM	#2
garyw O-F Administrator	Why not just null out the relative velocity difference with translation thrusters or Attitude MFD V3.2 Attitude MFD V3.2 ?

07-19-2012, 02:40 AM	#4
palebluevoice Loud, fat weirdo	Undocking inherently MUST make the two spacecraft fly in opposite directions. You can unlatch the docks, unscrew them; etc., but it still won't seperate them. "Objects in motion will stay in motion unless otherwise acted upon" If they're relative speed is one inch per second, they will seperate at one inch per second for all eternity(or until they crash into each other after a couple thousand years when the dragonfly hits the ISS in the butt). Therefore, anytime you undock, you must take manuevers to correct the reletive speed of the spacecraft; as Gary said, the attitude MFD has a mode that allows you to cancel relative velocity; alternatively, you could just use the dock MFD to display the relative the velocity. Happy space travel! Last edited by palebluevoice; 07-19-2012 at 02:40 AM. Reason: italic corrections

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07-19-2012, 01:19 AM	#3
icedown Donator	When I'm doing this, I usually deploy the first piece from the cargo hold and dock the XR5 to it, then I've got a solid base to start putting it together from. I've found the URMS very hand also, and it fits nicely in the XR5's bay.

07-19-2012, 11:12 AM	#5
C3PO Donator	Quote: Originally Posted by palebluevoice Therefore, anytime you undock, you must take manuevers to correct the reletive speed of the spacecraft; as Gary said, the attitude MFD has a mode that allows you to cancel relative velocity; alternatively, you could just use the dock MFD to display the relative the velocity. The problem is that when you release a module from DF, the module "inherits" an "undocking velocity" relative to the XR5. Even if you null the relative speed between the module and the XR5, they will begin to drift as soon you jump back to the DF. Singleplayer formation flying with 3 vessels is not easy. IMHO icedown's solution is the way to go. It's sort of the same way the ISS was built, but the RMS is replaced with a Dragonfly. Transfer the first module to the XR5 docking port, and the problem is solved.

07-20-2012, 12:34 AM	#6
KuatYards Ejection Seat Tester	Thanks for the help, i tried to stabilize maually from the DF... that failed... thanks icedown, when i read that i went should have thought of that... thanks

07-20-2012, 01:44 AM	#7
Cairan Donator	Hmm, which brings us to the idea of having a station keeping module or script so that unfocused vessels in the vicinity of a given target can autonomously do station keeping (ie. null out relative velocities by RCS)...

07-20-2012, 02:07 AM	#8
Zatnikitelman Wandering lonely as a cloud	Quote: Originally Posted by Cairan Hmm, which brings us to the idea of having a station keeping module or script so that unfocused vessels in the vicinity of a given target can autonomously do station keeping (ie. null out relative velocities by RCS)... There was an addon that did that, I want to say the name was Intermod2, but it could maintain a relative position.

07-20-2012, 02:23 AM	#9
icedown Donator	DG lifeboat with remote control killrot is what I use to stabilize it before I dock back up. It's much easier to hit a spinning station with the DG than my XR5.