STS-133: Discovery enjoying early pad flow – Agency FRR may slip
Discovery is behaving well during the early part of what is her final pad flow, with only one issue reported as the stack continues Launch Pad Validation tasks (S0009). Away from Pad 39A, managers are beginning their departmental Flight Readiness Review (FRR) meetings, leading up to the key Agency FRR – which is likely to slip to just days prior to the launch date.
STS-133 Pad Flow Latest:
Thanks to an on-schedule rollout to the pad, Discovery has a good amount of contingency time in her flow, in the event of an challenging issue interrupting the complex ballet of pre-launch operations.
“Shuttle Transfer and mate to Pad-A (A5214). Call-to Stations was completed on time (1600 EDT) with 1st motion at 1923 EDT. The stack was ‘hard-down’ at Pad-A at 0149 EDT,” was listed as the official times for Discovery’s rollout.
Discovery’s Interim Problem Report (IPR) count was only up to 41 at the time of rollout – the last of which – relating only to a loose strap – being charged prior to the departure from the Vehicle Assembly Building (VAB) on Monday evening.
“IPR 0041 to ET (External Tank) Mechanical: A loose protective cover strap was identified and required repair before rollout to Pad-A to avoid potential damage to the ET Foam,” noted the NASA Test Director (NTD) in processing information this week (L2).
“The team moved the D-South platform back into the mate position to support access, replaced the protective cover, re-inspected the D-south platform and moved back to the stow position, and re-inspected the MLP (Mobile Launch Platform) Zero-Level as a result of the D-South Platform movement. No damage was noted as a result of the loose strap.”
Once at the pad, Discovery – as the STS-133 stack – underwent the initial S0009 operations, involving the extension of arms and connections between the shuttle and the MLP.
“Launch Pad Validation (S0009) Call-to-Stations was complete at 0139 EDT (Tuesday),” added the NTD report. “Orbiter Access Arm has been extended. Crew Module hatch has been opened. ET Intertank Access Arm extension is complete. ET GOX Vent Arm extended and the hood has been lowered. Fixed Service Structure to MLP Freon lines have been connected.”
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With the Rotating Service Structure (RSS) rotated to the mate position, the orbiter was powered up for the first time at the pad on Wednesday for checkouts. Engineers also worked on mating the Ground Umbilical Carrier Plate (GUCP) to the External Tank, prior to carrying out leak checks.
“OV-103 powered up at 0855 EDT and powered down at 2018 EDT (Tuesday). RSS was rotated to the mate position at 2038 EDT Tuesday. ET GUCP electrical mates are complete,” added the NTD report in midweek.
“Hazardous Gas Detection flex hose connections to the GUCP is complete. GUCP vent line leak checks could not be performed due to orbiter powering down (moved to Wednesday first shift – resulting in:) GUCP leak checks are complete and good.”
The importance of a good leak check on the GUCP relates to the issue which caused scrubs during both STS-119 and STS-127′s tankings. Part of the solution involved a new two-piece flight seal being installed into the hardware.
Since the redesign to a two-part seal – and the correction of misalignments on the External Tank Carrier Assembly (ETCA) mounts, or feet – no leaks have been detected during topping operations since STS-127.
Checkouts have also been completed on the Power Reactant Storage and Distributation (PRSD) systems, aligning the flow for hypergolic propellant servicing operations. Work also took place on the Space Shuttle Main Engine (SSME) Flight Readiness Test in the second half of this week.
“Prerequisite operations supporting hypergolic propellant servicing are in work. PRSD GO2/GH2 and LO2/LH2 system checkouts are complete,” added the NTD report. “The SSME Flight Readiness Test, Helium Signature Test, and Ball Valve Leak checks began on Wednesday (V1046, V1292, V1308).
“SSME FRT and Final SSME positioning for flight are complete. Helium Signature test and SSME Ball Valve leak checks to be performed.”
“Rolled from the VAB to Pad A on Monday evening. Have completed pad validation and SSME hydraulic operation,” added KSC Ground Operations. “Working preps for the helium signature test.”
Only one issue has been noted during the pad flow to date, relating to an issue being noted during the Solid Rocket Booster (SRB) Enhanced Data Acquisition System (EDAS) checkouts.
“SRB EDAS checkout was successfully completed on the right hand side, however, during checkout on the left hand side IPR 0042 was taken,” noted the NTD. New IPR 0042 to SRB Electrical: During EDAS checkout the left-hand EDAS box, channel 1 indicated reverse phase. A wiring issue is suspected in the box.
“Following discussion with SRB element, a trouble shooting plan is being developed. This constrains Ordnance operations (S5009). Paper is in work for troubleshooting planned for Monday.”
Discovery is safely housed inside the protection of the RSS, which also provides access to areas of the stack for her engineers during number functional tests which are scheduled during this early stage of the pad flow.
“Orbiter Weather Protection (OWP) will be extended. SRB aft skirt purge checkout was successfully completed. ET LOX/LH2 auto component functional and hardwire checks are complete. 1st motion checks and ET camera functional checkout will be performed (late in the week). 50-1 and 50-2 triple flips have been lowered.”
However, the NTD reports that the RSS will be reopened over the weekend, noting “Weekend Work: OWP, Triple flips and RSS retract/extend for KSC Family Day,” with Ground Operations added: “Having a Family Day at KSC this weekend for the families to look at the facilities. Will be retracting the RSS Saturday morning for that event. Will re-extend the RSS Saturday afternoon.”
Over at the NASA centers, managers are beginning their departmental FRR meetings for the mission, with the large MOD FRR conducted on Friday (presentations on L2 – several articles in work).
Numerous meetings will take place, leading up to the SSP (Space Shuttle Program) FRR and Agency-level FRR – which will ultimately set the launch date for STS-133, still tracking November 1.
“RSRB (Reusable Solid Rocket Motor) (NASA/MSFC): The STS-133/BI-144 Level 3 pre-FRR is on Monday, September 27. ET-137: The Lockheed Martin Senior Manager Review team will meet Friday evening. Propulsion Systems Engineering & Integration (NASA/MSFC) Project FRR is noon on Monday, September 27,” were listed by the Shuttle Standup/Integration report (L2).
“Orbiter (USA/JSC): OPO (Orbiter Project Office) FRR is Wednesday, September 29. Chief Engineer (NASA/JSC) JSC Engineering pre-FRR is Tuesday, September 28. Flight Operations (USA/JSC) FO FRR was held Thursday. There are no issues.”
The STS-133 L-30 day Bench Review will take place on September 30 and October 1, ahead of the SSP FRR, now expected to be conducted over just the one day (October 7), as opposed to the usual two days. This is due to scheduling conflicts, which will also interrupt the schedule for the Agency FRR – which may slip a week to October 25 – less than a week ahead of the expected launch date.
“The following is the tentative schedule for STS-133/ULF5 readiness reviews. Note the conflict between the SORR (Stage Operations Readiness Review) and SSP FRR is being worked and may result in the SSP FRR being scheduled for only one day on 10/7,” added the Standup report. “The Agency FRR will also likely move. So stay tuned as the dates evolve.
“Agency FRR 10/19 (Expected to move to resolve HQ scheduling conflict. New date may become 10/25).”
With the relatively long gap between STS-132 and STS-133, work is picking up at a pace. Mission Management Team (MMT) chair LeRoy Cain noted everything remains on track heading into the run of FRR meetings.
“There is a lot of stuff going on this week and next. Several activities, several of us are traveling to FL early in the week for some of the activities going on there. Everyone is gearing up for that as well with all the pre-FRR meetings being scheduled,” noted Mr Cain via notes transcribed in the Standup report.
“Mr. Cain feels that we are where we need to be, and folks are really focused. He appreciates all the hard work.”
(Lead Photograph: Larry Sullivan, NASASpaceflight.com and MaxQ Entertainment)