Shuttle managers decide to advance STS-125 launch target to May 11
Following a meeting of the Noon Board at the Johnson Space Center (JSC), managers have decided to issue a Change Request (CR) and advance the STS-125 launch date by one day to May 11. The Agency Flight Readiness Review (FRR) will set the official launch date next Thursday.
STS-125 Flow Latest:
Processing is proceeding to plan, with only two issues under evaluation – relating to the ET Umbilical Well Camera/Flash system – which is currently undergoing troubleshooting – and final checks into the slight damage to the left radiator panel.
“S0600 vertical payload operations: Payload electrical and mechanical mates continue,” noted Friday processing information on L2. “Payload battery connections are complete and battery conditioning is in work. Currently, not tracking any payload issues.”
It is unlikely a repair will be required on the small area that was impacted by a torque wrench socket, though engineers are ensuring the radiator has no underlying cracks on the face sheet.
“Dinged radiator panel update: Ultrasound testing found that there are de-bonds (between the face sheet and the honeycomb) in the dented areas. Inspections will continue tomorrow to see if there are any cracks in the face sheet,” added Friday processing information.
“This will probably require the tape to be removed from the area for a visual inspection. Analysis is continuing to determine what, if any, repair is necessary.”
Meanwhile, Orbiter Mid-body Umbilical Unit (OMBUU) mate operations are complete, as the flow moves into closeouts.
“Orbiter aft closeouts (S1287) will begin this morning. Flight and mid-deck cable stow is planned to start today. Two waves of tankers are expected today for LH2 tank replenishment. Weekend Work: Flight and mid-deck cable stow continues. Payload ops.”
Launch Date Advancement:
In order to allow for three launch opportunities prior to the range becoming unavailable, managers began assessments into advancing STS-125’s launch date target by one day earlier this week – as reported by this site on Tuesday.
Several studies, with a number of options, were presented to the daily Program Requirements Control Board (PRCB) meetings over the past couple of days.
“A launch date change for STS-125/HST-SM4, accelerating by one day to May 11, was presented at the Noon Board on Wednesday,” noted Mission Management Team (MMT) manager Mike Moses, in a series of memos acquired by L2.
“All Shuttle elements reported “GO” for this option. The schedules for the HST team would remain nearly identical to the current plan. An official decision will be made at Friday’s Noon Board.”
During the evaluations, options were built to allow for the HST team to support the acceleration, after they initially noted they would not be able to support the move to May 11.
“As you all know, we talked the last two days at FRR about the possibility of moving the STS-125 launch date from 5/12 to 5/11. We are going to have a Daily PRCB discussion on Wednesday 4/22 to assess the supportability of a 5/11 launch date,” added Mr Moses.
“It’s time to make it official to make sure there no other issues with an earlier date (for example, flow control valve delivery, mission timelines, cryo supportability, flight design products, flight crew schedules, etc.).
“As stated in the SSP (Space Shuttle Program) FRR, the position of the HST team here at KSC is that an acceleration of the schedule cannot be supported. That said, we are going to go ahead and ensure that the rest of the Shuttle team could support 5/11 if it became a feasible option.
“I do not plan to ask the HST team for a Go/No-Go at this meeting – we will continue to assess their schedules and status throughout the week.”
Noted as Option 2, a slight realignment to the shuttle’s processing flow over the coming days out at Pad 39A has proved to be acceptable to the HST team.
“All signs are looking good to support a 5/11 launch date using Option 2. For those of you who weren’t at the Wednesday meeting, this option allows the HST processing to follow very closely to the previous schedule and shuffles the shuttle processing around to accommodate.
“The schedule is very near to zero margin, but it allows us to be ready to try a 5/11 launch.”
Meeting at the Noon Board on Friday, and working via a 10 page plan that allows the Hubble team to complete electrical testing within the May 11 timeline, Mr Moses announced the Change Request (CR) to re-target for the advanced launch date.
“Today’s meeting has concluded with a GO to make Option 2 the baseline and to step up to a launch date of 5/11,” wrote Mr Moses. “A CR will be submitted for signature outside-of-board.
“I would like to thank the Shuttle processing team and the Hubble payload processing team for all their efforts and collaboration to make this change happen. It’s really great to see the teamwork and I know this is just a precursor of the successes we’ll have as a joint team in orbit.
“A great deal of good work was done by the team in wrapping up the STS-125/HST-SM4 FRR this week. We appear to be in great shape as we approach the launch of this mission – stay focused.”
L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.