Rendezvous ops and OMS burns

[flaihai]

Hi there,

I was wondering if anyone could tell me in short or guide me to a link that explains how the shuttle is navigated into the initial vicinity of the ISS. While SSM07 simulates the docking I wonder how the two trajectories are initially matched... 

Another thing that came to my mind: SSM07 simulates OMS burns. But the actions that are required to initiate the burns are always the same while the outcome varies in burn time (at least). From reading the STS-113 Rendezvous Flight Data File I got the impression that in reality several variables have to be entered like variables to determine the target perigee (ITEM 19-21) and burn time. I just wonder if anybody has tried if these entries are possible in SSM07 or if there is a link that goes further into detail about this topic. 

Cheers,
Jan

[Becker07]

in short

The shuttle is launched at such a time so that its initial orbit almost matches that of the ISS.

Initial OMS burn after meco circularises the orbit. So the shuttle doesnt return to Earth.

Shuttle at this point is travelling at a lower orbit than the ISS and so is travelling faster than the ISS, so at this point the Shuttle is chasing the ISS ... Catching up.

Gradually the shuttle slows its approach to the ISS by increasing its orbital altitude, matching the altitude of the ISS by performing the burns you are talking about. The shuttle also fine tunes it's orbital alignment with the ISS.

Thats how it gets in the vicinity.

MCC uplinks burn targets to the GPC'S with the PADS / numbers given to the astronauts as a reference. I'm not sure if the astronauts input these themselves or it is simply a reference for what MCC has sent up. If I find a decent link will post back mate.

Hope that helps.

[flaihai]

Thanks a lot.
Very detailed and interesting information indeed! Exactly what I wanted to know! ;-)

Thanks again,
cheers,
Jan