Supporting Endeavour – engine installation milestone for Discovery

by Chris Bergin

As Endeavour continues her pad flow in preparation for STS-118, her older sister Discovery is heading through a number of key processing milestones, with the start of engine installation this weekend.

Discovery is being prepared for LON (Launch On Need) rescue mission support (LON-320) – in case Endeavour suffers a major problem on orbit next month. Discovery’s primary mission, STS-120, is due to launch October 20.

**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, already including a large amount of STS-120 presentations. 

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

**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**


Endeavour is enjoying a reasonably smooth pad flow at launch complex 39A, as preparations proceed towards her payload being installed into the cargo bay on Sunday. An APU (Auxiliary Power Unit) hot fire test has also successfully taken place.

‘Fuel Isolation Valve A is open, should be closed Troubleshooting shows no valve movement. Either no power or bad valve. APU hot fire complete. Picked up IPR (In Process Review) on an isolation valve failure. Not a constraint to completing confidence run.

**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**

‘Need to perform more troubleshooting on valve to determine whether to change out or not,’ noted processing information, which added that a ‘lightning strike 0.45 miles outside of Pad-A midweek,’ wasn’t close enough to cause a problem.

The dreaded words of ‘hail damage’ were also noted late in the week, although it’s not certain when this occurred. ‘Will give presentation on hail damage to tank and hits to orbiter; these were all very small,’ added the NASA integration report at the end of the week.

A full MOD FRR (Flight Readiness Review) was conducted this week (16 presentations – over 500 pages – on L2), which found “no significant issues,” although STS-118’s EVA 4 remains in the balance based on consumables. 

Pre-empting the milestones for Discovery, NASA information spoke of a ‘big week for Discovery,’ which opened with Monday’s installation of the OBSS (Orbiter Boom Sensor System) in her cargo bay. Payload pre-mate tests have also been conducted, although ET (External Tank) door functionality tests have been moved to next week.

Due to lengthy CSCS (Crew Shuttle Contingency Support) capacity on the International Space Station (ISS), Discovery’s launch date – in the event of a rescue mission – is targeted for October 5, only 15 days before her primary mission launch date.

Engine installation begins Saturday, with SSME (Space Shuttle Main Engine) 1 and 2 being installed into Discovery’s aft. Ongoing work to her TPS (Thermal Protection System) is proceeding well, with 12 more tiles being replaced on her belly.

‘V5005 Preps for installation of SSME #1 & #2 pick up today; installation picks up Saturday,’ added processing information on Friday. ‘Weekend work: Payload Premate Test, MRL rigging, SSME #1 & #2 installation, ET door work, TPS ops, dome heat shield work.’

Meanwhile, MAF (Michoud Assembly Facility) in New Orleans appear to have won their latest ET (External Tank) battle, with Discovery’s tank (ET-120) likely to ship next week – behind schedule, but within requirements for LON support.

‘All ramps for ET-120 are on except 2028 and 2013 stations. Preparing to put these on next day or so. Able to put all cable trays on, are routing harnesses and performing electrical tests and checkouts,’ added Lockheed Martin/MAF information. ‘Moving forward to meeting July 20 completion date.’

STS-120, commanded by US Air Force Colonel Pam Melroy, will deliver launch package 10A, which consists of the US Node 2 (with four DC-to-DC Converter Unit (DDCU) racks and three Zero-g Stowage Racks (ZSR) installed), a Power and Data Grapple Fixture (PDGF) for the station’s robot arm, and a Shuttle Power Distribution Unit (SPDU).

Node 2 – which will also provide a docking port for future shuttle missions – will be the first pressurized habitable module delivered to the station since the Quest Airlock was installed in June, 2001. Also on this flight, the P6 solar arrays will be moved from the Z1 truss on top of the Unity module to its final position at the port end of the truss.

The mission will have new elements to deal with, which were handled by the PRCB (Program Requirements Control Board) re-baselining in June 2006.

‘STS-120 was originally baselined in the FDRD on January 23, 2003 with a February 19, 2004 launch date. Following the Columbia accident, the mission was removed from the FDRD. Recently the ISSP has decided to accelerate the ISS International Partner (IP) Module missions by one flight. This includes the STS-120/ISS-10A (Node 2) mission,’ noted the presentation.

‘The STS-120 mission requirements have been updated to include not only the Node 2 installation but also the definite transfer of the OBSS Integrated Boom Assembly and the P6 relocation task (previously planned for the STS-119 (ISS-15A) mission). The STS-119 mission has been deferred until after the delivery of the IP Modules.

Mission objectives include: Unberthing Node 2 from PLB and install on ISS Node 1 Port ACBM. A Crew Rotation, involving Expedition 15 Flight Engineer Clayton Anderson, who will return on STS-120, which also carries his replacement, Daniel Tani, to the station. Tani will return on shuttle mission STS-122.

Other mission elements for the six docked days on the ISS include the Transfer Water and Critical Items. Transfer OBSS IBA to ISS. Relocation of P6 from Z1 to P5 and re-activate P6, which requires back-to-back EVAs. Protect P6 52 Hr Deact-to Reactivation thermal constraint. Get Ahead Tasks – and ISS Reboost and Flyaround Imagery – Prop Margin Dependent.

Following the re-baseline, the mission may be extended past its initial 11 day mission, with the post-Columbia mission elements coming into play. This includes Late Inspection, which is required after undocking to check for any damage on orbit from space debris.

‘Late inspection cannot be accommodated with current mission content; mission duration increase to 13+1+2 would be required to support pre-undocked late inspection but not possible on non-SSPTS OV-104 vehicle; moving the OBSS IBA transfer task to STS-118/ISS-13A.1 would allow pre/post-undock late inspection,’ added the presentation.

At present, the OBSS (Orbiter Boom Sensor System) role in future missions includes stowing the arm on the ISS due to clearance issues with some future payloads. Recently, NASA cancelled the option of building a mini-boom to mitigate this issue.

Other changes included the ‘as expected’ switch to LC-39A, from pad 39B, due to Pad B’s role now restricted for a LON (Launch On Need) requirement to support STS-125, before heading to modifications to support the Ares program.

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


(Video section is FREE, but you need to sign up as a member of the forum to enter the video section of the site. We only use your e-mail to send you your password. It will not be used for spam etc.)

** Job Opportunities** 

Related Articles