Docking, RCS and Camera (PS4)

[Elroy Jetson]

Guys,

 

I'm playing again after a lengthy break from the game.  I am have terrible problems using RCS and docking.  I'm playing on PS4.

 

my trouble is with the camera view and finding a constant and repeatable view so that I can learn the controls.  I think this is a pain and different than those who play on PC.  can anyone suggest a camera view that doesn't glitch around during RCS maneuvers?  Is it possible to get the craft rotated so that up/down and left/right feel natural and are repeatable?  I have spent hours with the docking training mission but I'm ready to give up.  i get the rot/Lin difference.  I think it is just finding a camera mode that works for me.

 

do most players fly from behind the craft?  What are the free, locked, orbit and whatever else modes intended for?  Which one works for docking?  Do you turn OFF the SAS  while maneuvering with RCS?

 

thanks for sharing your secrets...

Edited September 5, 2019 by Elroy Jetson
Typo

[vossiewulf]

1. When you arrive a few hundred meters away, use regular staging mode controls to point yourself at a spot that's say 50m out on a line from the docking port you intend to dock with.

2. Switch to docking mode and set it to Linear mode. Accelerate toward the starting spot you're aiming for. Do NOT give yourself any acceleration other than purely in the direction you're pointing.

3. When you get close to your intended starting point, accelerate in the reverse/retrograde direction and bring yourself to 0.0m/s relative velocity.

4. Switch to docking/rotational mode, and use RCS to line your craft up as close as possible to the axis of the docking port.

5. Right click on your docking port and select "control from here".

6. Pick which direction is "up", and rotate your craft to be at a zero degree alignment to that up direction, which should be aligned with your intended docking port as well. That way, from this point the up and down RCS controls will move you up and down relative to the docking port, and side to side works the same. Makes it very easy to know which direction key you need to hit at any given time.

7. Right click on the target docking port and select "Set as Target".

8. If you lined yourself up correctly, on the navball your nose should be pointed very close to the target direction as shown on the navball.

9. From here, it doesn't matter what camera view you're using, as you don't really need to see. All you need to know is the relative speed you're moving, that you're pointed at the docking target, and the distance to the docking port.

10. Use the LINEAR up/down left/right RCS controls to get your nose pointed right at the docking port target.

11. Once aligned, accelerate toward the docking port. Doesn't matter how fast you go, just that you're only moving .2m/s -.3m/s when you get there.

12. Once you get close to the docking port, use the linear RCS controls to once again bring yourself to a dead stop. Use the same steps described above to refine your axis alignment and rotation until it's really really close to the same axis as the docking port. This will usually make your nose move away from the docking port target again, so once again use the linear RCS controls to move you back until your nose is pointed dead at the target.

13. Now accelerate toward the docking port again. Continue to use the linear RCS controls to keep your nose pointed at the center of the docking port. You can switch to fine control mode (capslock on the PC) which can make small adjustments easier.

14. Hit the docking port at .2m/s, if you're lined up right it will instantly dock.

Below, docking a 2000 ton station resource arm and a 77-kerbal orbital bus, complete manual control, no docking mods used.

 

Edited September 5, 2019 by vossiewulf

[Elroy Jetson]

I just tried again and rage quit.  I was lined up, accelerated directly toward the port and it just bounced off and sent me spinning.  I can't stand it anymore, I give up.  Thanks for trying.

[vossiewulf]

33 minutes ago, Elroy Jetson said:

I just tried again and rage quit.  I was lined up, accelerated directly toward the port and it just bounced off and sent me spinning.  I can't stand it anymore, I give up.  Thanks for trying.

If you un-rage quit, bouncing off means you were probably moving too fast at the docking port, if you move slowly they have a magnetic effect and will pull themselves together even if you weren't aligned perfectly. So like I said, try to be moving no more than 0.2m/s.

[bewing]

Well, there are several reasons for bouncing off.

1) When the magnetic field kicks on, SAS will generally fight it. The closer the two vessels get, the more fighting happens. Then one suddenly wins with great violence, and your ship goes flying away. Answer: turn off SAS just before contact -- or turn it off, then on, then off, then on .... Doing that will reduce the violence of the magnetic attraction, because SAS will fight the attraction more gently.

2) Too much speed when the magnet kicks on (as vossiewulf said). Depending on the vessel mass, the magnet can add a lot of speed -- but the magnet may not get the docking port pulled around into perfect alignment before you bounce off. Answer: use your RCS retro thrusters to slow you down by half once you are within a couple meters of docking.

3) Your vessel is too heavy to turn with RCS. To get a docking, the ports must be lined up exactly. There's a reason why docking is considered one of the hardest tasks, both in the game and IRL. You need to control both the linear motion of your vessel, and the rotation, and have everything lined up right at the moment you touch. It's hard! Answer: more RCS thrusters, more reaction wheels, and take the docking process even slower.

4) Mismatched docking ports. If one of the two docking ports was turned around backwards when you built the vessel, or if they are different sizes, then you won't be docking today. Answer: do a really really close visual inspection of the docking ports on the two vessels in the VAB, and check their action menus, and make sure you can see two identical ports facing each other.

 

One tip is to put a pair of something small on the top and bottom of your rocket. Especially if they are tall and skinny such as antennas. They help you aim for your docking, and they let you orient yourself to the camera.

Another tip is to turn off the "roll/pitch/yaw" axes for your RCS thrusters. This makes it so that SAS only controls rotation, and RCS only controls translation. This can greatly simplify maneuvering during the final stages of docking -- because all you have to do is control the RCS.

Edited September 6, 2019 by bewing