STS-125 launch target moves to February 17 – crucial week for Hubble
STS-125 has been given a new “work-to” launch date of February 17, pending a November 5 meeting that will likely result in a Change Request (CR) to officially re-align the near-term launch manifest.
Hubble troubleshooting is proceeding well, with NASA engineers preparing to switch over from the Side A control system, to the back-up Side B.
Those preparations are on track, with the Science Data Formatter (SDF) on Side A of the Science Instrument Command and Data Handler (SIC&DH) “recovered” to the point that the hardware has been confirmed as a hard failure.
Last week’s recovery is, however, providing additional insight into the SIC&DH condition, as well as providing additional monitoring of the science payload.
Atlantis’ mission to service Hubble has now moved to the right by five days on the projected launch date, which continues to track February.
This latest refinement was confirmed by STS-125 Mission Director Chuck Shaw, with the current target also continuing to point towards Discovery acting as the LON (Launch On Need) vehicle STS-401.
“At the SSP/ISS (Space Shuttle Program/International Space Station) scheduling meeting, it was agreed to by the SSP Manager to aim STS-125 at 2/17 for a ‘work to’ date, rather than simply stating ‘Mid-Feb’,” noted the memo.
“Earlier, the scheduling community had asked for 2/12 to be looked at, but that is somewhat OBE (Overtaken By Events) now. That will also then aim STS-401 at 2/24 (HST+7).”
A scheduling meeting will take place on November 5 to confirm the refined launch date targets, which are now focusing on two opportunities, the latter an alternative launch date – in May – based on the potential of problematic scheduling issues with the February target.
“Evidently, the senior managers within SOMD (Space Operations Mission Directorate) and SMD (Science Mission Directorate) have agreed that a decision will be made on Nov 5th for pressing on towards the Feb opportunity or a later one (May).
“Not sure when a manifest CR will be put into coordination, since it appears that everyone is able to keep moving forward based on the ‘work to’ date while the HST troops come to grips with getting the telescope switched over to the B side and also assess the status of the replacement avionics.”
The removal of the HST payload from Atlantis has been proceeding throughout the weekend, with the canister set to depart from Pad 39A on Monday. Work will then take place to prepare Atlantis for her rollback to the Vehicle Assembly Building (VAB).
“Are on target to move vehicle from Pad A to VAB High Bay 3 on October 20,” noted United Space Alliance Ground Operations on L2. “Payload Canister hoisting and Payload Ground Handling Mechanism positioning to Wings and Ladders in support of HST Payload transition into the canister on Monday.”
Atlantis departure will be followed by the transition of Endeavour from Pad 39B to 39A, follow her stand-down from STS-400 requirements.
Now tracking a November 14 launch for her primary STS-126 mission, an October 25 arrival at 39A will have built-in flexibility for that launch date.
“On Pad B, are continuing preparations for moving OV-105 to Pad A on October 25, 2008,” added Ground Operations. “When get to Pad A, will have four contingency days for launch on November 14, 2008.”
STS-126 is currently undergoing a series of Flight Readiness Review (FRR) departmental runs, following last week’s milestone MOD FRR (17 presentations on L2). No major issues are currently being reported in the run up to the SSP FRR.
“The STS-126 Payload Readiness Review was held at KSC,” noted one example on L2. “Have open paper, mainly concerning ECLSS (Environmental Control and Life Support System) issues for the six man crew. Most of this paper will still be open when the vehicle rolls to Pad 39A.”
This payload review has been aided by the latest analysis on the “Leonardo” Multi-Purpose Logistics Module (MPLM), via a Verification Loads Assessment (VLA) – which was initiated by an ability to add additional payload to the module.
“MPLM weight for the racks showed that five racks are out of tolerance for weight/C.G (Center of Gravity),” added Flight Operations and Integration. “This issue is being worked, but we have plenty of margin. Additionally, are now expecting racks to return lighter than expected compared to original VLA studies.”
Discovery/Dual LON/STS-119 Latest:
Overall, Discovery is the main factor via what is now a dual LON requirement, which opens with supporting Endeavour’s mission by being ready to launch on a rescue early next year.
The two main issues relate to the timely delivery of External Tank ET-130 from the Michoud Assembly Facility (MAF), and the delivery of a new RCC (Reinforced Carbon Carbon) panel (10R).
“ET-130: Processing is nominal. ET-130 is in final assembly position 3. Are working TPS (Thermal Protection System) preparations for nose cone installation,” noted Lockheed Martin/MAF on L2.
“The tank will be moved to Bldg 420 on about October 15. Trying to allow moving tank completion date in from November 21,” which would be within the required schedule.
Lockheed Martin are also pushing forward their delivery date of 10R, although engineers at the Kennedy Space Center (KSC) are looking into the back-up plan of a donated panel, one that has previously flown with Atlantis and Endeavour.
Due to the unique ‘fit’ of these panels, which are mainly orbiter specific, fit checks have been carried out on these ‘spare’ panels all last week, with the results expected in the next few days, as normal processing continues.
“RCC fit checks on the OV-104 and OV-105 panels are complete,” added processing information. “SSME (Space Shuttle Main Engines) electrical connector mates were rescheduled for Monday. The team continues to work preps associated with ET Door Functional; scheduled for Monday.”
L2 members: All documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, updated live.