Station keeping below ISS

[ElPelado]

This is my first post in this forum.
And I have a question: When you have two satellites, if one is lower than the other one, then the first will move faster, wich means that if we start when one is right above the other one, the lower one will "escape" the higher one and the distance between both will grow....

So how does the shuttle stay below the ISS during the RPM without moving forward? Do they use a special manouver?
Please explain me this because I am working on something related to rendezvous and docking and I just can't understand this.
Thanks

EDIT: one more requst. DO you know those diagrams where you see the approach of the Shuttle (for example) where you see the atltitude of the shuttle and the range to the ISS, from the ISS frame??
Looks something like this:

Does anybody know where I can find one like that, but real (I mean, for a real shuttle to iss approach)??

 

[Urwumpe]

So how does the shuttle stay below the ISS during the RPM without moving forward? Do they use a special manouver?
Please explain me this because I am working on something related to rendezvous and docking and I just can't understand this.
Thanks

First they stop relative movement by the optical sight, then they do the RPM. While the RPM, they do in fact, slowly gain speed.

 

[ElPelado]

First they stop relative movement by the optical sight, then they do the RPM. While the RPM, they do in fact, slowly gain speed.

So they are not REALY station keeping? There is a little relative movment?

 

[Urwumpe]

So they are not REALY station keeping? There is a little relative movment?

The stop all relative movement by the RCS before the RPM AKA station keeping, but during the RPM, they of course are in a different orbit as the ISS.

EDIT: Also, the relative navigation plots are found inside the Rendezvous checklist.

http://www.nasa.gov/centers/johnson/pdf/229565main_RNDZ_124_F_1.pdf

 

[ElPelado]

THANK YOU THANK OU THANK YOU!!!!!!!