In a first for the Space Shuttle programme NASA made a surprise decision at 1840GMT to roll the shuttle Atlantis back to launch pad 39B following a weather forecast at 1500GMT that predicted winds at Kennedy Space Center from the tropical storm Ernesto of only 55-60kt, allowing the shuttle stack to be protected by the launch pad's rotating service structure (RSS).
Earlier in the day NASA shuttle programme manager Wayne Hale had been down beat on the expected launch date, suggesting September could be abandoned completely.Speaking at the 2040GMT status briefing NASA launch director Michael Leinbach said, "this is the first time we've reversed a roll back," adding that the Shuttle would be at the pad again by 2400GMT and be ready for launch by 6 September with a normal three-day countdown process.
Although Atlantis' window for its 11-day International Space Station construction mission STS-115 is from the 27 August to the 13 September a launch after the seventh would present a logistical problem, with insufficient time between Shuttle and Soyuz dockings and departures. A 7 September launch window deadline exists because Russia's Federal Space Agency (FSA) was preparing for a 14 September launch of its Soyuz rocket that is carrying the ISS expedition 14 crew, which will now have to be on the 18th.
The FSA was prepared to move the flight to 18 September if Atlantis' ascent was delayed from the 27 August to the seventh, which it has, and is now in discussions with the US agency about what to do for a possible 8 September shuttle lift off; but the FSA would accept no later launch.
This is because an Atlantis flight after the 8 September, for its 11-day STS-115 mission to the ISS, would mean a 20 September launch for the Soyuz and the Soyuz that is already attached to the ISS, and would return to Earth with two of the members of the current ISS expedition 13, would land on the 29 September in darkness. It is the landing in darkness that is unacceptable for safety reasons to the ISS international partners' rules.
The RSS would protect the shuttle as it encases the cargo bay and therefore much of the Orbiter. The RSS allows the vehicle's cargo bay doors to be opened to load payloads. It is retracted before launch.
Source: FlightGlobal.com
