Endeavour’s engines removed ahead of Discovery’s ET-128 mating

by Chris Bergin

As Discovery’s External Tank (ET-128) prepares for mating with the twin Solid Rocket Boosters (SRBs) on Saturday, Endeavour’s SSMEs (Space Shuttle Main Engines) have been removed.

With Atlantis in the midst of processing towards the flagship STS-125 mission to the Hubble Space Telescope, the intricate ballet of flight processing on the fleet is continuing on track, with only the External Tanks proving to be the critical paths.

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 **LIVE news on Endeavour STS-126 Processing**

**LIVE updates on Atlantis STS-125 Processing Flow**

**LIVE updates on Discovery STS-124 Processing**

STS-124 Latest:

Discovery is well ahead of the timeline to make the rollover date of April 28, following the delay of STS-124 to May 31 – caused by the late delivery of ET-128.

‘Completed weight on wheels test, which went well. Completing a few tile repairs. Plan to do weight and C.G. (Center of Gravity) next Friday. Will be ready to mate with Orbiter on April 28,’ noted the latest Shuttle Stand-up report.

‘OPO (Orbiter Project Office) Rollout review will be held on Monday. They are currently not carrying any special topics.’

Expanding on the activities that saw Discovery placed on her wheels – which is used to check the landing gear functionality along other required leak tests – Friday processing information confirmed Discovery has no issues being worked inside her Orbiter Processing Facility (OPF).

‘The vehicle was powered up and good Landing Gear uplock indications were observed. The RH (Right Hand) main gear was lowered. The LH (Left Hand) main gear and the NLG (Nose Landing Gear) were re-pinned and separation harnesses installed. The side hatch has been closed.

‘The 50-1 door gouge repair was completed yesterday and the door is scheduled to be installed today (Friday). The T-0 disconnects are now scheduled for April 17, with rollover operations following on April 18. Weekend work: None planned.

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The chances the launch could slip a few more days is currently being successfully mitigated by United Space Alliance (USA) workers in the VAB, who are pushing through pre-mate activities without issue. Mating with the Solid Rocket Boosters (SRBs) has been advanced one day to Saturday.

‘External Tank: ET-128 (VAB HB-4E): ET checkout cell preps for lift are complete,’ added Friday processing information. ‘Preps for ET Mate continue with mate scheduled for tomorrow. SRB/RSRM: BI-134/RSRM-102 (VAB HB-3) SRB alignment is complete. Platform ops is scheduled for today in preps for ET mate tomorrow.

‘In VAB, preps for tank mate are in work. Making last repairs on ET. Planned to mate tank on Sunday, but will accelerate this to Saturday.’

STS-125 Latest:

Engineers are continuing on track with the preparations for Atlantis’ trip to Hubble. Flow timelines have been aided by what is now classed as a ‘best case’ scenario of an October 8 launch date for STS-125 on the latest Integrated Milestone Chart – which also documents Atlantis’ two additional flights of STS-128 and STS-131 that will follow.

No major processing milestones are being worked on Atlantis at this time, as she undergoes a series of functionality tests on specific elements of hardware.

‘Completed the push test on the ET doors. In process of working MPM (Manipulator Positioning Mechanisms) functional (UPDATE: Complete with no anomalies). Completed test on starboard side; working port side,’ added the Stand-up report.

‘Installed R2C on 17R (Reinforced Carbon Carbon (RCC) Panels). Working to configure the left side. Put chin panels up and will be torquing them in place.’

Processing information on Friday did point to continued troubleshooting on Atlantis’ Fuel Cell 3, which is undergoing evaluations on its flow meter. So far, the device appears to be in good working order, though engineers will – as always – double check the results.

“FC-3 flow meter, picked back up with troubleshooting. The Flow meter was powered up using the external power supply and Nicolet recorder. No over-current was observed. Data review is underway. This process will be repeated today for all of 1st shift to allow the circuit to “cook”.”

Atlantis will also have to wait a little longer for the replacement of her aft radiator retract hose – which ‘famously’ kinked during payload bay door closure pre-launch (STS-122) before being guided back into place via a long pole.

The replacement hose was accidentally contaminated before being shipped from the vendor, though they spotted the mistake and will now ensure the hose is cleaned before heading to KSC for installation.

“Freon coolant loop 2 de-servicing completed to support R&R of the aft radiator retract hose assembly,” added processing information on Friday. “Aft radiator retract hose assembly is planned to start (pending arrival of the assembly) and continue on Saturday. The installation will pick back up next Monday.

“Yesterday, during final inspection for shipping it was determined that the flex hose cleanliness was compromised and will require cleaning at (the manufacturer) prior to shipment. Updates to follow.”


Endeavour is – for the most part – still in post flight processing, following her very successful STS-123 mission. As part of her processing milestones, Endeavour’s SSMEs have now been removed from her aft, ahead of being refurbished for a future mission.

“In process of removing engines today. Will begin engine removal from OV-105 this afternoon and continue this work until midnight. Will complete this work until all three engines are back in the engine shop by end of shift on Friday. (Engines 2 and 3 removed first, Engine 1 last).

“FRCS (Forward Reaction Control System) checkout, which was completed Thursday. Will begin OMS (Orbital Manuvering System) pod checkout next week. Continuing with post-flight TPS (Thermal Protection System) inspection (90 percent complete).”

Now a fleet-wide issue, the radiator retract hoses on Endeavour are also being checked, after she joined her two sisters in the kinked hose club post STS-123. However, opening checks – involving the use of x-rays – are showing no damage to the hose in question.

“Performed x-rays earlier in the week on the forward starboard flex hose. There were no issues with the x-ray. Will be doing payload bay door cycles next week to determine if hose retracts into the box.

“Radiator retract container for Endeavour (forward starboard contingency item) can be delivered to Huntington Beach for (testing) around May 9. Targeting first week of June for delivery back.”

Another post STS-123 element involves work on the FES (Flash Evaporator System) primary A controller, which failed shortly into Endeavour’s launch last month. Testing has shown it was the hardware that failed, as opposed to associated Ground Support Equipment (GSE).

“FES primary A controller troubleshooting is complete to date. The FES GSE was mated to the Primary B controller and successfully tested, validating the GSE. As a result, it is suspected that the FES Primary A controller has failed,” added processing information.

“For FES primary controller, looking at April 28 delivery date to support R&R on OV-105. Weekend work: SSME removal post ops, side hatch limit switch rigging, and ET umbilical door inspections.”

External Tank Status:

Workers at the Michoud Assembly Facility (MAF) in New Orleans are continuing their efforts to protect the realigned delivery dates for ET-127 and ET-129 – both required for the launch of Atlantis on STS-125 and Endeavour’s supporting role as the LON-400 rescue mission requirement.

The new delivery dates are fluid, as production on the tanks continues, with a clearer idea of how the new shipping dates will relate to the downstream manifest expected in around a month.

Classed as “streamlined processes” on specific areas of the tanks – the status of the ETs were threatening to cause several months of delays. However, a mixture of a Technical Interchange Meeting (TIM) and a resulting engineering mitigation effort – which involves the aforementioned streamlining of production requirements – is proceeding well.

“ET-127 (STS-125): Tank is in final assembly position 3. LO2 nose cone fit check activity on front end of tank is in work. On intertank externally, continuing with panel venting and internally, continuing with harness routing,” noted processing information from Lockheed Martin/MAF.

“Close to finalizing bipod, temp sensor, and heater harness wire bonding, which will get them going into bipod closeout sprays in near future. LH2 internal mast installation is complete. LH2 lower ice/frost ramp pour trims continue. Six of upper pours are in trim.

“Progressing through longeron activities. Implementing productivity initiatives on these such as elimination of plug pulls and associated mock-ups. Ready for next-to-last sprays on longeron. Will continue to streamline this process on ET-129 and up. Installed aft double bellows LO2 feedline section on tank.

“ET-129 (LON-400/STS-126): Poured a fourth LO2 ice/frost ramp on front of the tank during intertank fitting. Doing preps inside intertank for harnesses. Had all LO2 ice/frost ramp base sprays done, and they are in trim. Six more are in final trim stages.

“LOX elbow has been delivered and should be installed at end of week. Then, will deliver aft interface hardware to the tank for installation.”

Interestingly, the following tanks – starting with ET-130 – are not showing any issues with their production flows, which has been aided further by the recent delays in the near term manifest.

Manifest Latest:

Shuttle managers conducted a SSP (Space Shuttle Program) Council meeting this week, which discussed the current manifest situation, the requirements of the Constellation program (CxP) during the final couple of years of shuttle operations, and the subsequent transition.

Headed by shuttle manager John Shannon, notes from that meeting point to an ability to still complete the remaining manifest by 2010 – though there are “challenges”.

“Had a SSP Council meeting, which focused on three topics: 1) Manifest supportability – team members discussed how their element supports the manifest. Have challenges, but are in good shape to complete the Program in 2010,” noted the outline of the meeting.

“2) Near term activities – What SSP can do to help CxP. They focused mainly on Ares I technology to help them accelerate their program. 3) Long-term future – How to transition from a SSP team to a SSP/CxP team. This is in the initial stages. Will begin to roll out plans over the rest of the year.”

Under discussion next week will be the status of the required transition of Pad 39B and one of the VAB’s High Bays, ahead of the test flight of Ares I-X – currently scheduled for April 2009.

Pad 39B is already undergoing a level of Constellation related modifications ahead of the test flight, whilst still being able to host Endeavour as the LON-400 stack during the launch of Atlantis on STS-125. The VAB High Bay in question will be required to stack Ares I-X ahead of its test launch.

Mr Shannon will head to the Ares I-X “Minus One Year” review meeting on Monday as part of those ongoing discussions.

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