NASA evaluates options for Atlantis’ STS-129 Launch Window in November

by Chris Gebhardt

After nearly two years, orbiter Atlantis is set to make her return to the International Space Station (ISS) in November following her extremely successful flagship mission (STS-125) to repair the Hubble Space Telescope in May 2009. However, meetings have been taking place on Wednesday to discuss the target launch date due to a number of constraints.

STS-129 Evaluations:

As part of this return to ISS construction/maintenance duty, Atlantis has been undergoing pre-mission processing for STS-129 in Orbiter Processing Facility Bay 1 (OPF-1) at the Kennedy Space Center ever since her return to the Florida spaceport on June 2 following STS-125’s landing in California in late-May.

As of this week, engineers and technicians in OPF-1 – under the direction of veteran orbiter flow director Angie Brewer – are nearing the completion of their processing efforts on Atlantis.

Final Orbiter Docking System (ODS) external closeouts are scheduled to begin on Thursday, September 17 following a final retest of the ODS this week.

Over in the Space Station Processing Facility, Atlantis’ payload, the Express Logistics Carriers 1 & 2 (ELC 1 & 2), are nearing the end of their pre-launch processing phase.

According to Tuesday’s STS-129 Flight Director’s memo – available for download on L2 – “All Integrated Verification Testing (IVT) has successfully been completed on ELC2; IVT on ELC1 is scheduled to begin tomorrow.”

Additionally, closeout work on Atlantis’ Solid Rocket Boosters (SRBs) is underway in High Bay 1 of the Vehicle Assembly Building (VAB) following the completion of stacking operations last week on MLP-3 (Mobile Launch Platform 3).

On Wednesday, program managers officially approved the mating of External Tank 133 (ET-133) to the SRB stack.  SRB/ET mate is scheduled to take place on Monday, September 21 – beginning two weeks of mating and closeout operations on the tank before the arrival of Atlantis in the VAB on October 6 and her mating to the tank on October 7.

A2If all goes as planned, STS-129’s payload will be transported to Launch Pad 39A in the early morning hours of October 11 – followed two days later by Atlantis.

In all, Atlantis is now expected to undergo a 30-day processing flow at the launch pad before the opening of her launch window on November 12.

As of this past Monday, Shuttle and Space Station Program managers had hoped to target November 9 as the opening of Atlantis’ launch window.  However, that no longer appears to be a possibility.

According to processing information via a STS-129 Flight Director’s memo, “ISS Program did not have any luck getting the Russians to accelerate the launch of 5R/MRM-2; it will remain launching on 11/10 and docking on 11/12.”

The acceleration of Atlantis’ launch to November 9 was contingent upon the advancement of the MRM-2 launch to earlier in November.

“Accelerating the STS-129/ULF3 launch date was contingent on 5R also accelerating to avoid both 5R/MRM-2 and Atlantis docking within ~ 5 hours of each other on the same day.”

As such, the Change Request to officially accelerate Atlantis’ launch date to November 9, which was submitted to the all-powerful Program Requirements Control Board (PRCB) earlier this month, will be withdrawn and all teams will proceed toward a No Earlier Than November 12, 2009 launch of Atlantis and STS-129.

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However, as of Monday, September 14, the KSC STS-129 LCWG presentation – available for download on L2 – listed the available launch window for Atlantis as November 9-12.  

Given that Nov. 9, 10, and 11 have been eliminated as possible launch opportunities, the KSC launch team only have one day to get Atlantis off the pad before standing down until at least mid-December because of Dual Docked Operational (DDO) constraints on the ISS from the departing Soyuz TMA-15 spacecraft, a potential Atlas V rocket launch from Cape Canaveral on November 14, a scheduled Delta-IV launch from Cape Canaveral on November 18, and a Solar Beta Angle Cutout that begins on November 20 and lasts until December 5.

Nevertheless, some get wells in the window may be possible from both the international and domestic side.

A3“ISS Program/Russian negotiations on the Soyuz TMA-15 undocking topic appear more positive; there may be some small movement possible, possibly even a move out of the STS-129/ULF3 operational window,” notes the Flight Director’s memo.

If a delay to the Soyuz TMA-15 undocking can be achieved, the DDO concern could be trimmed or possibly even eliminated.  As such, a Joint Operations Panel is reviewing the possibility of clearing all or some of the DDO concerns for “a Soyuz undocking with an Orbiter docked at ISS.”

As of now, it appears that some of these concerns are classed as “major concerns” for certain launch dates and “minor concerns” for others.

All of these concerns were discussed at an IPT (Integrated Product Team) meeting on Wednesday, with follow up discussions taking place during the Joint Operations Panel meeting immediately following the IPT.

Nevertheless, it appears that the Russian Space Agency is seriously looking at the possibility of delaying the Soyuz TMA-15 undocking and subsequent Soyuz TMA-17 launch.

Currently, the TMA-15 undocking is scheduled for November 23 with the TMA-17 launch slated for December 7.

However, it appears the Russians are looking at delaying the TMA-15 undocking to December 7 – which would go a long way toward eliminating the DDO concerns for Atlantis – and the TMA-17 launch to December 21.

As such, if the DDO concerns can be cleared or eliminated, November 13, 14, 15, and 16 would then be available as possible launch days for Atlantis from an ISS perspective.   However, the Atlas V rocket family is looking to launch the Intelsat 14 satellite around November 14.

According to the STS-129 LCWG on Monday, “Atlas V has range after we do. Range requires approximately 48 hours to reconfigure between launches. We have opportunities on November 9-12 and then would stand down for Atlas launch.”

In this case, assuming the Atlas V team continues to target November 14, does not relinquish their launch opportunity to Shuttle, and launches on time, Atlantis’ next opportunity to launch would be November 16, before once again standing down for the scheduled Delta IV launch of a WGS satellite around November 18.

“A Delta IV rocket currently has the Eastern Test Range reserved on Nov. 17-20,” notes the STS-129 Flight Director’s memo.

NASA and KSC Test Director Office are currently looking at the possibility of negotiating a slip of the Delta IV launch to allow Atlantis additional launch opportunities at the end of the window.

Nevertheless, the hard constraint of a Beta Angle Cutout begins on November 20.

“The beta cutout begins on November 20 and extends through December 5; Russian vehicle traffic on the other side of the beta cutout could impact launch opportunities then,” notes the Flight Director’s memo.

However, a launch attempt on November 21 may also be possible, but only if the +1 day of the 11+1+2 day mission was eliminated pre-launch.

L2 members: Documentation – from which the above article has quoted snippets – is available in full in the related L2 sections, now over 4000 gbs in size.

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