Tim Furniss/LONDON

Completion of the International Space Station (ISS) is likely to be delayed until 2004 - ten years later than planned when the project was first announced in 1984 and about one year later than the date announced by NASA in 1996.

Earlier this month, NASA and the Russian space agency (RSA) confidently named the first four crews to inhabit the ISS and agreed with international partners the 45-flight on-orbit assembly flight sequence due to begin in June 1998.

The launch of the US Habitation Module astronaut living quarters, however, completing the full ISS assembly, has been delayed to December 2003 at the earliest. Although NASA has not stated it publicly, this ambitious schedule provides no leeway for unforeseen launch delays, or even accidents.

Two Russian and two US Shuttle flights are on schedule for 1998. The Russian Functional Cargo Block, called the FGB, will begin the ISS launch programme in June; the STS88/Endeavour will follow in July; the Russian Service module in December and another possible Shuttle flight the same month.

The flight schedule outlined so far consists of:

1999 - eight missions, including a Russian Soyuz TM launch of the first crew to operate aboard the initial ISS configuration, and the Canadian robotic arm Mobile Servicing Center;

2000 - nine missions, including the US Laboratory Module; five flights will follow in 2001, including the Japanese Experiment Module;

2002 -11 missions, including the European Columbus Orbital Facility;

2003 - eight missions, ending with the US Habitation Module.

The ISS will also be supported by a series of unmanned Russian Progress M tanker supply craft.

NASA and the RSA have agreed that the ISS will have alternate national commanders. The first three-man crew, led by the USA's commander William Shepherd, will be launched in a Soyuz TM in March 1999.

The second crew will be led by Russia's Yuri Usachev on the STS98/Atlantis in June1999. The third will be under Ken Bowersox on a Soyuz TM in late 1999, while the fourth, under Yuri Onufrienko, will fly the Shuttle in 2000.

Source: Flight International