General Question Real world STS operations

[chevelle505]

So setting up another STS mission and it got me wondering, in real life..would nasa ALWAYS close the rss around the orbiter before a launch regardless of payload needs to protect the orbiter from weather etc or was this only don’t to load payloads? What about occasions where there was no payload, just going to the ISS for example?From what I remember it seems like they’d roll out the shuttle roughly two weeks before launch. When did they close/open the rss? Was it kept around the orbiter until right before the launch?

 

[Urwumpe]

So setting up another STS mission and it got me wondering, in real life..would nasa ALWAYS close the rss around the orbiter before a launch regardless of payload needs to protect the orbiter from weather etc or was this only don’t to load payloads?

Yes, always, because the RSS has to be closed for tanking the OMS/RCS with propellant.

When did they close/open the rss? Was it kept around the orbiter until right before the launch?

I would need to check the countdown specs again, but maybe @DaveS will be faster than me to answer that question, he is quite the expert regarding the Shuttle ground operations.

 

[DaveS]

Yes, always, because the RSS has to be closed for tanking the OMS/RCS with propellant.



I would need to check the countdown specs again, but maybe @DaveS will be faster than me to answer that question, he is quite the expert regarding the Shuttle ground operations.

After the first few launches and as they made the system operational, the RSS MOVE TO PARK operation was done during the lengthy hold at T-11 hours, somewhere around Launch-(L-)18 hours. There was a sizeable margin(around 5 hours IIRC) built into the schedule to allow the operation to be delayed without impacting downstream operations and this frequently happened.

And, yes the RSS was needed not only for servicing the orbiter OMS/RCS propellants through the Hypergolic propellant Umbilical System (HUS) but also the loading/draining of the fuel cell reactants through the Orbiter Mid-Body Umbilical Unit (OMBUU, "ohmbuh"). The RSS was usually rotated to the MATE position around the orbiter about 6-12 hours after the vehicle was harddown on the mounts at the pad and the Crawler had reached the nominal park position just outside the pad gates.

This coincided with other post-arrival operations such as extending the Orbiter Access Arm, the GOX Vent Arm and the Intertank Access Arm and connecting the MLP electrical, data and fluid lines to the pad. All part of Operational Maintenance Instruction (OMI) S0009 Launch Pad Validation. The rollout itself was OMI A5214 SSV XFR TO PAD.

 

[DaveS]

This is an archived copy CBS's Bill Harwood Launch Countdown Summary for the second STS-114 Launch Countdown: https://web.archive.org/web/2006042...w.com/shuttle/sts114/fdf/sts114countdown.html
It was created from the official OMI S0007.200 LAUNCH COUNTDOWN BARCHART.

 

[chevelle505]

Awsome guys thanks! I always wondered this, so am I correct with rollout to the pad being roughly two weeks before scheduled launch day?

 

[DaveS]

Awsome guys thanks! I always wondered this, so am I correct with rollout to the pad being roughly two weeks before scheduled launch day?

Around that time, yes but could be longer if more operations had been added on such as on STS-114 where they added a Integrated Tanking Test (ITT, S0019) to verify that the design modifications done to the External Tank in the wake of the Columbia accident worked properly. For that rollout was on April 6 2005, with the tanking test occurring on April 14 2005 with launch scheduled for May 15 2005: https://web.archive.org/web/20060221120111/http://spaceflightnow.com/shuttle/sts114/050414tanking/

 

[chevelle505]

Gotchya Thanks for the info guys, y’all are a wealth of knowledge…much appreciated!!