Processing Atlantis – engineers move into STS-122 preparations

by Chris Bergin

As it should be, all three NASA shuttle orbiters are in the midst of their various stages of processing, with Atlantis hitting the milestone of completing SSME (Space Shuttle Main Engine) removal this week.

Post flight processing is proceeding on schedule, with TPS (Thermal Protection System) inspections, the removal of Atlantis’ windows and the OBSS (Orbiter Boom Sensor System) marking a busy week for the orbiter’s move from post flight STS-117 processing, into preparations for STS-122.

**The most comprehensive collection of Shuttle, Ares, Orion and ISS related presentions and mission documentation, plus expansive daily processing documentation and updates are available to download on L2 **

L2 Members: All documentation used in this article is available to download on the L2 section.

Special STS-118 L2 Section now live, with all the MOD Flight Readiness Review presentations (x16), a newly updated Flight Plan and handbooks, along with a large amount of mission documentation. STS-122 documentation build-up already begun.

**LIVE news updates on Endeavour STS-118 PAD FLOW**

**LIVE news updates on Atlantis STS-122 Processing**

**LIVE news updates on Discovery STS-120 (LON-320) Processing**


STS-122 is set to be the final mission of 2007, currently targeted for December 6. Atlantis will be carrying the European module ‘Columbus’ to the International Space Station (ISS), in what was supposed to be her penultimate mission prior to retirement. However, the decision to retire her after the STS-125 Hubble Servicing Mission was reversed.

The mission will also conduct an Expedition 16 crew rotation on the ISS, with ESA (European Space Agency) astronaut Leopold Eyharts – a French Colonel – swapping places with NASA astronaut Daniel Michio Tani, who arrives onboard the ISS on STS-120 in October.

As part of Atlantis’ post flight processing – following June’s STS-117 mission – the final SSME was removed from her aft late Wednesday, just a few days after sister ship Discovery received two SSMEs ahead of STS-120 – the third will be installed next week.

TPS inspections are also nearing completion, as Atlantis starts to turn the corner into preparations for her 11 day mission at the end of the year.

‘FRCS (Forward Reaction Control System) functional completed last week with no issues. Thermography completed and data given to engineering. SSME removals Wednesday,’ noted processing information.

‘OBSS removal this week. Starting to remove windows 1 through 6 this week. TPS inspections ongoing this week; are 88 percent complete and up to 86 cavities.’

**UPDATED: Ride home through the fire, sparks and plasma of re-entry with Atlantis, Discovery and Endeavour. FOUR Stunning high quality 2hr, 355-400mb Camcorder and HUD videos – from payload bay closure to post landing – several more videos showing landing from 90,000 ft also available**

Following Atlantis’ arrival back from the Dryden Flight Research Center (DFRC) – piggybacking cross country on top of the SCA (Shuttle Carrier Aircraft) – Atlantis received a soaking from a Florida rain shower whilst awaiting demate on the SLF (Shuttle Landing Facility) . However, processing information this week noted Atlantis managed to avoid any detrimental effects from the rain.

‘Were rained on coming off SCA; IR (Infra Red) scans completed this weekend indicated wet area very minimal, so should be able to dry for waterproofing.’

Rarely mentioned in the media is the vast amount of work that goes on behind the scenes during the processing flow, as teams of United Space Alliance teams work off continually modified baselines for each mission, with STS-122 being no exception.

Among the hundreds of pages of baseline and processing flow documentation are elements of modification work, sometimes laid out many months in advance by shuttle managers at the Johnson Space Center (JSC).

One example is the installation of an ET Umbilical Camera Flash (Sync Cable and Flash), which is an improvement for the ability to collect imagery of the expended External Tank (ET) after separation on orbit, in order to evaluate any foam liberation from the tank.

‘Installs flash unit in the LH (Left Hand) ET umbilical well with data cable routed to the digital camera in the RH (Right Hand) umbilical well,’ noted the 100 page integrated ‘freeze point’ presentation, created for the all-powerful PRCB (Program Requirements Control Board).

‘Flash unit replaces one of two LH 16mm cameras to provide supplemental light to illuminate the external tank (ET) for imagery during separation. Flash will fill in shadow areas during daylight and provide illumination for night launch.’

Another processing modification during the flow is the replacement of inserts in the OMS Pod, which is one of many risk reduction processes – one that may seem minor, but is a sign of the on-going effort to eliminate potential problems before they occur.

‘OMS Pod Ceramic Inserts Replacement With Bonded FRSI Plugs. Eliminates ceramic inserts in the forward areas of the OMS pods in order to reduce the risk of the inserts becoming a debris source during flight,’ added the presentation, one of four large STS-122 baseline/flow presentations, available to download on L2.

‘Replaces inserts with bonded FRSI plugs in 20 tiles on each side of the vehicle at the forward edge interface and the forward/outboard corner of each OMS pod. Tiles are installed on carrier panels that are rarely removed as part of normal OPF (Orbiter Processing Facility) flow operations.’

Other modifications include ECO (Engine Cut Off) Point Sensor System Wire Separation, as part of the ongoing effort to fully understand the issues relating to the ECO sensors on early Return To Flight missions.

The sensors were also the basis of a major pre-flight topic for STS-118 – including healthy dissenting opinions – which discussed the LCC (Launch Commit Criteria) relating to data from additional voltage measurements on th sensors, which will be implemented in Endeavour’s countdown – details on L2.

STS-122’s modifications include the implementation of hardware changes to mitigate critical wire redundancy separation violation, relating to the ECO sensors which check the level of LH2 and LOX in the tanks, as they fill pre-launch, and empty on the ride uphill to orbit.

‘Installs in-line resistors to the return lines for each of the LH2 and LO2 ECO sensor circuits (8 total) to completely isolate the instrumentation circuit from the sensor circuit.

‘Physically separates the ECO 1 sensor wiring from the ECO 2 wiring and the ECO 3 sensor wiring from the ECO 4 wiring (both LO2 and LH2 circuits). Installs arc-track protection barrier material where physical separation is not possible.’

Pre-launch milestones for Atlantis include the building up of the boosters inside the VAB around September 17, ET mate with the boosters three weeks later, with rollover of Atlantis targeted for October 30.

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


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