STS-124: Discovery arrives in VAB – Vacuum Chamber incident

by Chris Bergin

Veteran orbiter Discovery departed her Orbiter Processing Facility (OPF-3) early on Saturday, for the short trip to the Vehicle Assembly Building (VAB). First motion was at 07:17 local, arriving in the VAB at 08:05.

Meanwhile, a spacesuit test inside Johnson Space Center’s Building 7 was terminated, following a vacuum chamber leak, this week. The crewmember was in no danger, though tests on the facility will be carried out before the next scheduled runs take place next week.

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 **LIVE updates: Endeavour Dual LON and STS-126 Processing**

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

**LIVE updates on Discovery STS-124 Processing – to Rollover**

Discovery Rollover:

Two days ahead of the required timeline to make the May 31 launch date target, Discovery will be mated with the awaiting External Tank (ET-128) and twin Solid Rocket Boosters (SRBs) in High Bay 3.

Timelines show that Discovery and her stack will arrive at Launch Pad 39A on May 3 – should mating operations proceed as planned – which allows for at least two days of contingency in the flow.

‘Vehicle on OTS (Orbiter Transporter System); gears are retracted. Ready to rollover at 7:00 a.m. EDT on Saturday morning,’ noted Integrated Flow Status. ‘In VAB, begun pulling platforms.

‘Have work to carry over after orbiter mate, but this was planned in order to get ahead. Still plan to roll to the pad on May 3. Constraints are in good shape.’

Orbiter/External Tank Mate prerequisite operations continued through Friday ahead of Discovery’s arrival in the transfer aisle, with no issues reported with either ET-125, or Booster Integration (BI-134) and the Reusable Solid Rocket Motors (RSRM-102).

Upcoming – after Discovery rolls out to the pad – are the Flight Readiness Reviews (FRRs). The Space Shuttle Program (SSP) FRR is scheduled for May 13 and 14, which will be conducted via video conference beginning at 8:00 am. CDT both mornings.

The final Agency-level FRR will be face-to-face meeting held at KSC on May 19.

As Discovery closes in on the launch date – with a refined lift-off time of 5:02:07 PM EDT, following the recent reboost of the International Space Station via the ATV – a level of attention will be placed on the final payload bay door closure for Discovery, due to the recent issues with the radiator retract hoses.

If this occurs again pre-launch, plans – and experience from Atlantis’ bent hose ahead of STS-122 – are in place, following meetings this week, which will continue to be refined.

STS-122: Hose related news content (all exclusives): *Issue found/fleet to be checked (December)* – *Atlantis found to have problem* – *Managers discuss forward plan* – *Use of pole to aid retract* – *Successful Retraction*

‘Held a couple meetings over last couple days on radiator retract hose. Appears have an increased probability of having a bent hose either on return or prior to launch when close payload bay doors,’ noted JSC Engineering.

While a special pole solved the issue for Atlantis, the hose in question was in her aft area of the payload bay. Forward hoses would be much harder to gain access to at the pad.

‘Flight rationale for launch depends on getting hose back in box. Forward hoses are difficult to access. Believe it’s worth having KSC determine now how to access this via scaffolding, etc.’

External Tank Latest:

Atlantis’ tank for STS-125 (ET-127) is continuing to undergo production at the Michoud Assembly Facility (MAF) in New Orleans, as its Ice Frost Ramps (IFRs) are trimmed and pressurization lines are installed.

A number of workers on the tank have been moved to ET-129, which is indirectly required for STS-125, due to its role with Endeavour when she is sat on Pad 39B – at the time Atlantis launches from Pad 39A – as the Launch On Need (LON-400) rescue shuttle.

“ET-127: Ice/frost ramps at stations 1374, 1399 and 1787 have been poured and are in process of being trimmed. Press lines have been installed on the tank, and they are in process of pouring station 1593,” noted processing information from Lockheed Martin/MAF.

“Two straight sections of LO2 feedline are on the tank. Are now installing press lines on aft cross beam assembly. Longeron trims are in process. As of Thursday, will continue to work critical path on ET-127, but will shift most of crew to ET-129 to keep progress on both tanks in balance.

“ET-129: Routing on inside of intertank. LO2 tank Barry mount trims are in work. Aft interface hardware has been installed.”

Vacuum Chamber Incident:

The incident with the vacuum chamber has no relation to the last aborted run of a spacesuit test, which occurred at the end of last year when the crewmember noted a smell of smoke from his EMU (Extravehicular Mobility Unit).

The incident on Wednesday related to the chamber itself, though it is not deemed to be risk to the test schedule at JSC. The crewmember was in no danger.

“Had a crewmember go through suited vacuum chamber run in Building 7. He experienced a facility issue where chamber leaked. Got back to 2.5/2.7 psi, did a nominal repress, and terminated run early.

“Crewmember was checked out, and he was fine. There were no issues with the crewmember or with the hardware. Will do additional processing to dry unit out before additional planned tests next week. No major impacts. Chamber is still under investigation but this won’t hold up anything.”

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