External Tank (ET-131) is being safely housed in the Vehicle Assembly Building (High Bay 2E), following its arrival from New Orleans this weekend. Manufactured by the Michoud Assembly Facility (MAF), the team earned praise from managers and astronauts alike, following their successful fight back from schedule issues, and the phenomenal performance of ET-129.
ET-131 will ride with Endeavour, currently tasked with both the STS-400 LON (Launch On Need) support for Atlantis’ STS-125 mission to the Hubble Space Telescope – currently scheduled for May – and Endeavour’s primary STS-127 mission.
STS-127, currently tracking a June 13 launch date, will complete the assembly of the Kibo Laboratory complex, with Endeavour carrying an array of payloads that will require a 15 day mission with five baselined EVAs.
Aside from installing the Japanese Experiment Module – Exposed Facility (JEM-EF), Endeavour’s crew will be tasked with replacing six batteries on the P6 truss.
The tank’s arrival was ahead of the required timeline by a couple of weeks, which earned thanks from shuttle manager John Shannon, who “congratulated the team at MAF for all of their hard work on getting this tank ready ahead of schedule.”
With four other tanks undergoing major production at the Lockheed Martin run facility, MAF find themselves in a much more comfortable position – compared to previous years since Return To Flight – despite the heavy schedule of downstream flights in 2009 and 2010.
However, ET program manager Mark Bryant noted his insistence that the engineering workforce should continue to ensure the tanks leaving the facility are of the best possible quality, regardless of the high flow of tanks required to complete the current shuttle manifest.
“It’s an ambitious schedule that will require continued high levels of performance from the team,” said Bryant, “performance that we are demonstrating every day in producing safe, high quality tanks.”
All four tanks used in the 2008 shuttle missions lacked any major foam losses, with STS-126’s year-closing flight with Endeavour enjoying a ride uphill with what is widely regarded as the cleanest tank to have ever flown during the eight and a half minute ascent into orbit.
The performance of the tank, ET-129, earned thanks for the MAF workforce from Endeavour’s crew, during their post flight visit to New Orleans.
“I got to space because of the hard work of each of you. It’s a team effort,” said STS-126 mission specialist Heidemarie Stefanyshyn-Piper. “I was just the lucky one to take the ride up.
“Every job here at Michoud contributes to the success of a mission, not just the folks physically working on the tanks. From the person who prepares meals through the purchasing department, I thank you for your work and contributions to mission success.”
ET-129 proved to be a major effort ahead of its trip to Florida, with the tank eventually shipped ahead of its previous planned schedule in support of the Space Shuttle Program (SSP) options to accelerate STS-125, to be used for adding earlier launch opportunities for STS-126’s short launch window in November.
Due to the on orbit issues with the Hubble Space Telescope (HST), STS-126 jumped a launch slot. However, the initial push to ship ET-129 to KSC in a timely fashion involved a three shift, round-the-clock, drive at MAF – which was also recognized by their NASA paymasters.
“Looking out across the crowd, there are a lot of folks here who put in a lot of dedicated hours and a lot of hard work to get ET-129 together and prepared for its launch,” said Chip Jones, NASA Michoud chief operating officer during a general assembly at the plant.
“On behalf of NASA, I would like to personally thank you for your dedication.”
Despite the successful turnaround into a smooth schedule for the upcoming tanks, challenges remain, not least via a potential extension of the shuttle manifest, and the requirement to create space for new tooling that will be used to build the Ares vehicles for the Constellation program.
ET-138 was set to be the last shuttle tank to be produced by MAF. However, with STS-134 close to being officially added to the manifest, managers have been working a plan to refurbish ET-122 – which was damaged during Hurricane Katrina, when it was hit by falling roof panels in the facility’s Cell A.
NASA has authorized Michoud Operations to perform a limited scope of work on ET-122 through April, with engineers inspecting the tank for damage to its pressure vessels and metal substrate.
“Transportation and Handling moved the tank to Bldg 420 just before Christmas, and technicians will perform shearography to inspect for possible concrete chips in foam,” noted MAF information.
“Technicians will also remove and replace Liquid Oxygen and Liquid Hydrogen umbilicals; perform borescope inspections; strip foam from damaged areas of the Intertank; and clean its internal surfaces.”
Currently, the plan is to make this tank available for LON requirements associated with STS-134’s mission to carry the Alpha Magnetic Spectrometer (AMS) to the International Space Station (ISS) – pending funding.
Also, in pre-emption of a possible extension being approved this summer, MAF have completed initial work on two additional tanks, ET-140 and ET-141, alongside a tooling plan that would allow utilization of new Ares machinery on additional shuttle tanks, as and when required.
The next tank due out of MAF is ET-132, which will fly with Discovery on STS-128’s logistics mission to the ISS. The tank is currently in final assembly, with “everything is proceeding nominally.”
L2 members: All documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.