Atlantis’ STS-125 mission to Hubble delayed to October – update

by Chris Bergin

The Michoud Assembly Facility (MAF) has completed a re-evaluation of the delivery dates for ET-127 and ET-129. The two tanks directly relate to the launch date target for STS-125 – the final servicing mission to the Hubble Space Telescope – and the LON-400 rescue mission contingency.

Monday Update: As a result of the evaluations, STS-125 has been delayed to October 8, STS-126 to November 10 and STS-119 to February 12, 2009 – dates that will be firmed up in the coming weeks.

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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**

New Launch Targets:

The realignment of STS-124 to May 31, and subsequent CSCS (Crew Shuttle Contingency Support) ability, means ET-127’s realigned delivery date will be within the margins for LON support of Discovery’s mission.

However, STS-125 cannot launch with CSCS margins, as Atlantis will be without the ‘safe haven’ of the International Space Station (ISS). Instead, Endeavour – sat on Pad 39B – will be ready to launch within a week of an emergency being called.

While ET-127 will launch with STS-125, ET-129 is Endeavour’s tank – for both LON-400 and her primary STS-126 mission. Ultimately, ET-129’s delivery date is driving the delay to the Hubble mission.

The overall delay is only around five or so weeks, which means MAF has managed to carry out a superb turnaround over the past few weeks, before which the concern related to delays as bad as several months downstream.

This is in part thanks to an internal TIM (Technical Interchange Meeting) conducted at MAF and MSFC (Marshall Space Flight Center).

‘MSFC is still aggressively working the feasibility enhancement. There was a Chief Engineer’s Review Board where they heard and approved many of the technical aspects,’ noted the latest Shuttle Stand-up/Integration report.

‘It has to be a combined effort with the technical team and the production team to get everyone working to make it happen. (Shuttle manager) Mr. (John) Shannon thanked the MSFC ET team for their effort over the last two weeks.’

Praise from Shannon was also noted directly on the stand-up report, which pre-empted Friday’s manifest meeting – with specific NET (No Earlier Than) dates now revealed on Monday.

‘Mr. Shannon thanked the MAF team on the work they’ve done on schedules and the flow in the last two weeks. The team will hear the new ET deliveries schedules at the Schedules Telecon (Friday). We will (then) start to look at dates at the Manifest Tag-up.’

Due to the requirement for both one of the High Bays in the Vehicle Assembly Building (VAB) and Pad 39B to be handed over to the Constellation after the Hubble mission, the delay to October for STS-125 will also have an affect on preparations for the Ares I-X test flight.

‘CxP will start attending because any date changes to the Hubble mission change the hardware that would be used for their Ares I-X test,’ confirmed the Stand-up.

ET Processing Status:

Accelerated work on both ET-127 and ET-129 now appears to have hit a steady pace, according to the latest status update from Lockheed Martin/MAF, with no further delays expected to the new launch date targets.

‘ET-127 (STS-125): The LO2 cable readiness installations are complete for last cover installation. Completed the LO2 harness routing and vent actuation tubing. The bearing mount closings are complete. All the rubber dam installations and cable trays are complete. Completed the ogive electrical harness and GO2 press line installations and leak checks are 95 percent complete. Have gotten into bipod harness routing and bonding of those harnesses.

‘All of the LH2 lower ice/frost ramps have been poured. Have gotten into press line installations on this and are setting up to get the cable tray installations going down the LH2 tank. At about 75 percent on the trim of the LH2 feedline base spray. Have sprayed the B pockets on the longeron on the plus and minus Y side, next will be the B&E pockets. Looking to do a combination of those pockets.’

‘ET-129 (LON-400/STS-126): For final assembly, have sprayed three LO2 ice/frost ramp bases. Poured another of the ice/frost ramps on the LO2 tank. Did all the window cutouts and the LH2 ice/frost ramps. Have now sprayed four of those LH2 ice/frost ramp bases. Have some of the new tooling in to help do a better job of protecting the foam as they trim out. Have completed the aft dome protective spray in anticipation of the aft interface installation.’


Meanwhile, the orbiter fleet are enjoying smooth processing flows inside their respective Orbiter Processing Facilities (OPFs).

Discovery is easily within her processing timelines, on track for rollover to the VAB at the end of the month. This flow is still dependant on ET-128 processing, which remains a threat to the May 31 launch target, though any slip would only be a matter of days.

“Wrapping up processing in the OPF. Did complete positive pressure testing. Working aft close-out and will be done in the next couple of days. There are a couple of cavities remaining that will be bonded this week. Plan to do final powerdown April 7,” added processing information.

“Vent doors were configured for OPF rollout yesterday (Thursday). Aft compartment closeouts continue through Friday. SSMEs (Space Shuttle Main Engines) are configured for rollout.

“Are continuing to process ET-128 in HB4 (High Bay 4). Got the 7 inch QD (Quick Disconnect) on, and are leak checking it. Concluded the spray of the aft hard point. Still on track to mate that tank by April 13, which supports orbiter mate on April 28.

“Weekend Work: Orbiter – None. ET-128: ET Camera closed Loop functional test and LH2/LO2 17 inch Disconnect measurements/adjustments are scheduled.”


Atlantis’ flow – one which is seeing her undergo a number of modifications for the flight to Hubble – now has some increased flexibility via the change to an October launch date.

The main focus of processing at present relates to a changeout of a Reaction Control System (RSC) thruster and work on several RCC (Reinforced Carbon Carbon) tiles.

“Continuing the FES (Flash Evaporator System) functional. (Picked up) ammonia servicing. Doing the reductions for R5D thruster removal, which is scheduled for Saturday. Continuing with payload upload activities.

“For the RCCs, completed 16 and 17 on LH (Left Hand) side; continuing to work 17 RH (Right Hand). On Tuesday, completed the air data probe torque test; it was good, so will apply dry film lube to wrap that up. Continuing TPS (Thermal Protection System) processing.

“Weekend Work: R5D thruster replacement. SCAPE operations are scheduled for Saturday 3rd shift. Requires Orbiter power to be up through Saturday 2nd shift.”

One item of interest with Atlantis over the past week has been an issue with the left hand Air Data Probe’s (ADP) breaking torque on a mechanical actuator (clutch system) – as noted above. Special fixtures were installed in the OPF for an April 1 test, which proved to be successful in clearing the problem.

The ADPs are critical systems that are deployed ahead of landing, providing data on altitude, velocity, angle of attack, and other required data for the orbiter to fly herself towards the handover to the commander and pilot.

The potential issue was noted during normal processing, where engineers put the ADP through three complete cycles and two single motor cycles on each motor individually and then a dual motor cycle during each flow.

The results of the tests on the system – that is located at the lower edge of the FRCS (Forward Reaction Control System) – have now been summarized.

“Earlier this week, the mechanical team was down looking at the air data probe on OV-104 (Atlantis) that was getting hung up,” rounded up a report from the Orbiter Project. “They were worried that the actuator might be loosing torque, as seen in other mechanical actuators.

“Had a test and found out that the actuator is nice and strong and hasn’t lost any torque. It appears that the probe was getting hung up against some resistance stops.

“These stops are to keep it tight when fully deployed all the way out so that it doesn’t move around during entry vibration. It appears that some of the dry-foam lube off the stops has gotten worn off during the years.

“There was evidence of galling. Will clean it up, and think it will improve the situation. The actuator was not loosing any torque at all.”

Had the system failed the tests, it would have required a significant amount of work, due to the requirement of the removal and replacement of about a dozen tiles, and significant retesting of the ADP and avionics.

While ET-127 is not due at KSC for some time. Booster build-up is continuing to take place for the October flight.

“SRB/RSRM: BI-135/RSRM-103 (RPSF) Right Aft Booster build up: Instafoam Application to Stiffener Rings. Forward and Center Rings are in cure. Dew point readings were out of limits. Instafoam application to the Aft Skirt trailing edge is scheduled Friday. ETA Ring Cover Installation. Cover installation is in work.”


Endeavour is continuing her post flight STS-123 processing, as she presses ahead towards her LON support requirements for STS-124 and STS-125.

At least two windows will be replaced, following her recording breaking mission to the ISS, with three others being evaluated, while her engines are being prepared for removal next week.

She is also undergoing post flight Thermal Protection System (TPS) checks, while her Spacelab Pallet – which contained the Dextre robot – has been removed.

“The Spacehab pallet will be coming out this week (now out). Continuing with RCC thermography on the WLE (Wing Leading Edge). Have completed inspection on the windows. Windows 1 and 6 will be R&R’d. Have 3 PRs for Windows 4, 5 and 8 that are still being evaluated.

“Post-flight TPS inspection is 75 percent complete. Will be removing the TSA (Tool Stowage Assembly) Friday. Working engine removal preps, and the engines will come out early next week.”

Endeavour’s STS-126 mission is documented as the heaviest logistics flight on the manifest, as the Station builds up towards a six crew compliment. However, one item – a treadmill – has been removed from her payload. No reason was given for the change.

“STS-126/ULF2 mission, ISS decided that they will not fly the treadmill on the MPLM,” noted Flight Operations & Integration. “It will be delayed until the subsequent MPLM flight.”

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