Atlantis main engine removal delayed – ET repairs going well

by Chris Bergin

The planned removal of Atlantis’ engine removal – to check for possible RepliSet contamination – has been delayed, due to clearance issues surrounding the on-going ET-124 repair effort. The process will include an engine swap between Atlantis and Endeavour.

Meanwhile, repairs have been proceeding at a pace on ET-124, with over a third of the damaged areas now classed as repaired. Currently, workers are about six days away from fully repairing the tank that will fly on STS-117.

**The most comprehensive collection of STS-117 onwards related presentions and mission documentation are available to download on L2 **

**LIVE news updates on Atlantis STS-117 VAB Flow**

**LIVE news updates on Endeavour STS-118 (LON-318) Processing**

**LIVE news updates on Discovery STS-122 (LON-322) Processing**

Related documentation on L2: Major STS Flight Schedule Changes (New FAWGs) – March 27 – NASA White Paper on Manifest Changes – March 27 – Shuttle Flight Preparation Status Charts to STS-124. ET Repair Documentation – from start of March to April – plus more (vast).

**Previous articles related to the ET damage events: Article 1Article 2 – Article 3 – Article 4 – Article 5 – Article 6 – Article 7 – Article 8 – Article 9 – Article 10Article 11 – Article 12 – Article 13 – Article 14 – Article 15 – Article 16** Click for more screenshots of the damage.

Following NASA’s careful assessment of ET-124 hail damage, which led to the approval to continue with repairs – as opposed to swapping with ET-117, technicians have completed 938 out of the 2,741 areas of damage.

With the repair effort showing that around 300 areas of repair are being completed each day, it is possible that the tank will be repaired within a week. As far as the estimated repair schedule, work on the tank is only down by a day or two – well within the NET June 8 launch possibility.

However, those tank repairs have gotten in the way of the requirement to remove Atlantis’ SSMEs (Space Shuttle Main Engines), due to scaffolding – which was erected for the ET-124 repairs – providing lower than required clearance for the removal of the engines.

‘During a walkdown in preparation for engine removal, several scaffolding issues were noted. To ensure ET-124 repair efforts were not impacted, engine removal will be rescheduled to begin on April 24,’ noted processing information acquired by this site at the start of this week.

‘This change in the schedule is not expected to impact the rollout date of May 6 nor the NET launch date of June 8.’

**Ride home through the fire and plasma of re-entry with Atlantis on STS-115 – And now also with Discovery on STS-116 – TWO Stunning high quality 2hr, 355mb videos – from deorbit burn to post landing**

This was explained further by information produced a few days later, which noted clearances of only 1.5 inches, which isn’t enough, given the stack is capable of moving around three inches while inside the VAB (Vehicle Assembly Building).

‘Reviewed engine removal timeline and procedure: A question was posed to the Loads Panel on the clearances to the scaffolding and how much the vehicle would move once the engines are removed. Checked the clearances on the scaffolding, and in some areas have scaffolding clearance of only one inch or 1.5 inches. The estimate is the vehicle could move as much as three inches.

‘Postponed engine removal until remove scaffolding. This currently fits in the schedule, but makes the schedule a bit tighter. There was another question of how much the vehicle would move with only one engine removed, but that would still be too close.’

As stated, this does not alter the targeted May 8 rollout of Atlantis back to Pad 39B, although she’ll be rolling out with one of Endeavour’s SSMEs, as noted in a processing report: ‘SSME #2 will be swapped with OV-105 (Endeavour).’

The reason for the swap is believed to be because engine 2 on Atlantis needs to have its LPOTP (low pressure oxidizer turbo pump) replaced, when they remove it for the RepliSet contamination inspection. 

Endeavour has already had her SSMEs removed to check for contamination, which proceeded well, despite some level of contamination found, although no notes of concern were raised. Re-installation of engine hardware on Endeavour began Wednesday.

(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