If Space Shuttle Atlantis does not lift off this week, its next daylight launch date would be 26 October, but NASA has been considering a late September attempt, despite lighting conditions not being ideal. The US space agency requires daylight launches to monitor external tank foam loss during ascent, to verify design changes. But in the wake of the tropical storm delays to Atlantis's launch, pushing it back from 27 August to 6 September at the earliest, mission managers are studying a late September launch. "We have kicked off a study to review our requirement for lighting," says NASA Space Shuttle programme manager Wayne Hale.

Although Atlantis's window for its 11-day International Space Station (ISS) construction mission STS 115 extends to 13 September, a launch after 7 September would present a problem, with insufficient time between Atlantis arriving and a scheduled Soyuz docking.

Russia's Federal Space Agency (FSA) is preparing for an 18 September launch of the ISS expedition 14 crew on its Soyuz rocket. The Soyuz currently docked would undock after crew 14's arrival and land with two of the expedition 13 astronauts on 29 September.

To avoid logistical problems with this ISS crew exchange, Atlantis would have to be launched after 20 September.

Source: Flight International