NASA and its International Space Station (ISS) partners have agreed plans to reduce the number of Space Shuttle flights from the US agency's previously proposed 19 to 16, to ensure there is a realistic mission schedule in the years leading up to the Shuttle fleet's retirement in 2010.

Yesterday the heads of national space agencies also endorsed the latest ISS configuration and the assembly sequence of Space Shuttle missions needed to complete the station by 2010.  Not including two contingency flights, 16 Shuttle missions are now planned, with several science projects abandoned in favour of the delivery of essential components to the ISS.

The ISS configuration changed because most of the station's modules were designed to be launched on Shuttles in a 28-flight and assembly sequence. Due to the few remaining shuttle flights left, following Space Shuttle Columbia's loss in 2003, the Russian science power module and centrifuge module have been dropped.

The dropping of Russia’s power module was among the changes announced yesterday and the proposed Hubble space telescope servicing mission is also not listed on the flight schedule. “There have been obvious decisions that are painful to implement,” said NASA administrator Michael Griffin. However, the challenge for NASA is to restore the shuttle fleet to regular flight service to meet the target.

At yesterday's meeting at the Kennedy Space Center in Florida, the agency chiefs also committed themselves to an earlier-than-planned launch of several laboratories, including the European Space Agency's (ESA) Columbus module in 2007 and the Japanese Kibo laboratory module in 2008.

Present at the meeting were Canadian Space Agency vice president Virendra Jha, Russian Federal Space Agency chief Anatoly Perminov, ESA director general Jean-Jacques Dordain, NASA administrator Michael Griffin and Japan Aerospace Exploration Agency president Keiji Tachikawa.

Griffin said there were plans to preposition ISS spares in orbit via Shuttle ISS visits and hinted that that could also be done via commercially procured delivery services obtained as a result of NASA's Commercial Orbital Transportation Services (COTS) programme.

The deadline for COTS bids was 3 March. SpaceX submitted a solo bid, while Spacehab has teamed with two major US aerospace companies and foreign subcontractors. This could mean using Boeing Delta IV launches of Energia’s Progress M2 ISS cargo vehicle. Both SpaceX and Spacehab have bid for all four COTS categories: pressurised and unpressurised cargo, down mass and crew transportation. The winning bidders have to demonstrate cargo transportation systems by 2010 in order to win NASA supply contracts.


Read Rob Coppinger's view on the re-evaluation of the International Space Station's future 

Source: Flight International