Discovery launches after clean countdown

by Chris Bergin

STS-124’s mission has begun, following a smooth launch at 5:02pm EDT. This followed an issue-free countdown, aided by all ECO (Engine Cut Off) sensors performing without fault during tanking.

A small foam liberation event at around T+3 minutes is not being classed as a concern at this time, as foam liberation after around 2 minutes 20 seconds usually do not have the ability to cause any damage, should they impact the orbiter. Also, a Left OMS Secondary Gimbal Failure has no mission impact.

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**STS-124 Sub Section (over 1700mb already) – Includes Flight Plans, S0007 Documents. Mission Overview CGI Videos. Plus 25 Flight Readiness Review (FRR) Presentations, a multitude of mission presentations and extensive, live, processing flashes, updates. MMT level Live Flight Day Coverage has begun.

**STS-125/LON-400 Sub Section Special already over 1500mb in size – special section Now Live, with over 40 superb mission presentations.

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

**STS-124 News Articles**

STS-124 Flashes:

Tanking begins.
LH2 ECO sensors showed ‘WET’ as planned. Both LH2 and LOX tanks in slowfill. Awaiting SIM test and transition to fastfill.
LH2 now in fastfill, awaiting SIM test.
SIM ‘DRY’ Command applied to all four LH2 ECOs and all 4 LOX ECOs – Results: Excellent.
LH2 98 percent sensors ‘WET’, now in Topping. LOX still in Fastfill.
LH2 in stable replenish. T-3 hours and holding.
LH2 ECO checkout went well. LOX now in replenish. Tanking operations completed, with the tank in stable replenish.
Ice Team now at the pad.

Out of the T-3 hour hold, the STS-124 crew are now being ingressed into the vehicle.
No issues – bar one small Ground Support Equipment (GSE) valve (no constraint) – are being worked by the Mission Management Team (MMT).
Successful launch.

Debris event noted, but after ascent time that can cause damage.
LOMS Secondary Gimbal Failure – no mission impact.

STS-124 Countdown Overview Latest: 

Discovery 35th flight will be conducting a 14+1+2 duration mission – which involves nine docked days at the International Space Station (ISS). Her primary payload is the JEM PM/RMS (Japanese Experiment Module Pressurized Module/Remote Manipulator System.)

The timeline was recently changed from a 13+2+2 mission in order to accommodate the ISS BCM (Battery Charger Module) R&R. Should the mission change to a Flight Day 4 rendezvous, the BCM R&R would be deleted if margins do not support additional day. An additional day is reserved for post undocking unscheduled events.

‘Late addition of a mission objective drove mission duration change,’ noted documentation. ‘Addition of ISS Airlock Battery Charger Module change out to the joint mission timeline resulted in a new nominal flight day (new FD11) being inserted into the timeline.

‘BCM R&R was originally planned for the 1J stage, but accelerated for earlier return of Tox 4 batteries. BCM R&R will be performed on FD10, one day after EVA-3 and following final Airlock cleanup and EMU transfer.

‘Final transfers and hatch closure move to new FD11. New flight day effectively uses what was previously book-kept as a docked +1 day; FD4 rendezvous could result in this day being deleted. Also drove additional crew training and ISS procedures development.’

Interestingly, a problem with the two BCM’s riding on STS-124 was identified recently, which led to engineers spending the past few days identifying a solution. Sources note that a procedure will be in place for the crew to modify the BCMs on orbit in a few days.

Discovery will also be facilitating an Expedition 17 crew exchange – returning Garrett Reisman back to Earth, after leaving STS-124’s Greg Chamitoff on Station.

New Operations for STS-124 – Flight Readiness Review (FRR) Part 2:

New operations for this mission includes a LH2 ECO (Engine Cut Off) Sensor Bypass strategy, should failure occurs in OPS-9 and no significant impact to pre-launch timeline. MCC and KSC procedures are in place to support software bypass in both PASS and BFS Flight Software if required.

STS-124 will be the fourth flight of Primary Avionics Software System (PASS) and Backup Flight System (BFS) Operational Increment 32 (OI-32) – with the addition of one new PASS data patch for STS-124 (Raise Reaction Control System forward tank temperature upper limit to avoid nuisance alarms).

Discovery’s mission will also be the fourth flight of Multifunction Electronic Display Subsystem (MEDS) Integrated Display Processor (IDP) / Multifunction Display Unit Function (MDUF) combination, and the eighth flight of Miniature Airborne Global Positioning System (GPS) Receiver Shuttle – 3 String set-up.

STS-124 will be the tenth Space Shuttle flight of the IBM ThinkPad A31p PGSC and associated 28V DC Power Supply, the fourth flight of the A31p Docking Station, and the second flight of new Netgear Wireless Access Point.

This will also be the first mission which will involve the use of Mission Control’s ISS Flight Control Room (FCR-1) transitioned to the Linux workstations, which has been long in the planning.

‘The final flight specific integrated simulation was performed utilizing the new workstations and no significant issues were noted. ISS Increment operations will have operated utilizing the new workstations for around 6 weeks prior to the STS-124/1J mission.

‘The ISS MPSR workstations were transitioned after FCR-1 but will have run time on them prior to the joint mission. Facilities and Network are ready to support.’

Flight Day 2 will involve refined objectives, compared to recent missions, due to the unavailability of an OBSS (Orbiter Boom Sensor System) for Discovery, prior to her arrival at the ISS.

The usual FD2 Orbiter Inspection tasks – or pre-dock inspections – are not possible, due to the OBSS currently being stowed on ISS since STS-123, related to clearance issues with Discovery’s huge Japanese payload and SRMS (Shuttle Remote Manipulator System) elbow camera – which is restrained to prevent contact during ascent.

‘Flight-specific Starboard and Port wing RCC survey auto-sequences were developed from existing generic surveys,’ noted FRR documentation. ‘Starboard survey expanded to include more coverage of wing glove and wing tip; limited by SRMS reach and clearance to payload bay cargo, thus only the upper surface can be scanned

‘Port survey covers more area on wing tip, but at increased range compared to generic survey due to limited clearance viewing (under PLBD without elbow camera); zoom settings were adjusted to provide optimal resolution.

‘No special attitude maneuvers are required for lighting; nominal attitude and daylight/Earthshine are sufficient

‘RPM photography (during rendezvous) and imagery from ISS cameras (while docked) will be used to supplement the FD2 inspection data.’

An expansion on FD2 will follow during the mission via information in several new presentations acquired by this site.

Now on L2: A stunning 50 minute (1.9gb) high quality camcorder video of a special All Access tour of the VAB, Pad and OPF-3. Get up close with two orbiters, next to the engineers, ride the VAB elevator to the top of the building, walk around the pad and enter OPF-3 to within touching distance of Atlantis. FREE TRAILER NOW AVAILABLE – CLICK IMAGE.

The crew will also be tasked with gaining more data on the orbiter’s freon radiator hoses, which have been suffering from C-bend/Omega-bend issues over a number of previous flights.

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*

‘Crew procedure incorporated into Deorbit Prep checklist to capture imagery of all 4 Freon radiator hoses during payload bay door closure,’ noted another FRR presentation. ‘Per Shuttle Program, this is a highly desired requirement.’

Should Discovery require the alternative landing site of the Edwards Air Force Base (EDW), use of the new, shorter runway will come into effect – as previously reported by this site.

‘STS-124/1J is first flight to utilize EDW Temporary runway while permanent runway undergoes refurbishment,’ summarized an overview FRR presentation – with specific documentation acquired prior to the FRR. ‘EDW Temporary runway is a 12,000 ft long by 200 ft wide asphalt/concrete runway.

‘Additional 1,000 ft over/under runs are shuttle load bearing. Permanent runway is 15,000 ft by 300 ft wide concrete. Flight Rules and procedures in place to accommodate EDW Temp runway operations.

‘Brake Energy now managed to 52 Mft-lb. Protects against dispersions from tire fire limit of 70 Mft-lb, Drag Chute protects against tire fuse plug post landing limit of 42 Mft-lb.’

Several other new operation elements are also presented for STS-124, ranging from the modified EVA glove – as previously reported by this site – to new CO2 and Airflow management, Joint Emergency Egress procedures, and JAXA command and control function responsibilities.

Modified External Tank ET-128:

Always planned for the mission prior to STS-125’s servicing of the Hubble Space Telescope, ET-128 will debut additional debris mitigation modifications that have been developed as part of Return To Flight efforts.

ET-128 – which will ride with Discovery – will sport the modified LH2 IFRs (Ice Frost Ramps), welcomed after 32 divots and three related LH2 acreage foam losses have been registered since RTF.

The change to the ramps will result in a ‘reduction in cracks and delaminations which could lead to cryopumping foam loss,’ according to an overview presentation on L2, outlining the changes to the tank that have been approved, and a ‘reduction in voids which could lead to void/delta P foam loss.’

ET-128 will also debut the LO2 Feedline Titanium Yoke and TPS (Thermal Protection System) Redesign, following a flight history of 23 occurrences of yoke losses.

The design, currently authorized under contract direction (Task Authorization), replaces Aluminum with Titanium on the LO2 Feedline Yoke, leading to a ‘reduced ice formation, and a secondary benefit of ‘reducing the amount of TPS and reduces possible mechanical interference during articulation due to ice between the yoke/strut and Feedline.’

‘Significant debris mitigation redesigns implemented: LH2 Ice Frost Ramps (IFR) and LO2 Feedline Support Brackets,’ noted associated information. ‘ET-128 is first tank with single processing flow and more robust work access mats to protect acreage TPS (Thermal Protection System).’

The ‘robust mats’ holds an element of relation to STS-114, when a large piece of the Protuberance Air Loads (PAL) ramp liberated during Discovery’s ascent. This led to the fleet being grounded while the ramps were removed from all future tanks.

Though never confirmed, it is understood that the PAL ramp liberation was a one-off event, caused by original damage to the ramp at the Michoud Assembly Facility (MAF) being repaired with a patch – as seen in tank processing images – that was of similar size and location to that which liberated via cryopumping from the tank on STS-114.

The damage was, according to sources, was caused by crushed foam underneath the mats used by workers at MAF. With the new mats now in place, that risk has been removed.

Less reported is another change on the tank, implemented to mitigate recurring weld repair-related issues associated with the Al 2195 alloy on the SLWT (Super Light Weight Tank) tank.

This plan included the return to Al 2219 for complex curvature hardware and structural optimization to mitigate weight impact.

This is the second of three phases with the implementation process, first started with STS-116 (ET-123) and due to be finalized on ET-134.

While changes to the tank are all designed to improve safety, engineers have been required to carry out such modifications in tandem with ensuring the overall requirement of the tank is protected.

In certification notes, the recent changes are deemed to have no impacts identified for propellant quality or ice/frost prevention.

Thermal analysis – used to demonstrate break up altitude and launch probability requirement – showed the recent changes to the tank maintains 249,000 ft nominal rupture altitude and 89 percent launch probability. Critical margin of safety is unaffected (derived environments unchanged).

A clean flight will add more confidence to the tanks performance during STS-125, which will be without the safe haven of the Station, should serious damage occur with Atlantis.

The performance of sister ship Discovery, and ET-128, will go a long way to provide that increased confidence.

L2 members: All documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, updated live.

Click here for a range of superb STS mission specific music videos created by Max Q videos 

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