Atlantis launch date pushed back

Nasa is pushing back a space shuttle Atlantis mission to the international space station by four days to November 16 so that it can test an experimental rocket, the US space agency said.

The date will be officially confirmed by mission administrators on Tuesday during a meeting to evaluate preparations for the Atlantis mission.

The decision to push back the launch is intended to "optimise the agency's ability to launch both Ares I-X and Atlantis before the end of the year," Nasa said in a statement.

The Ares I-X is the first test flight for Nasa Ares I, an experimental rocket. Nasa said it has scheduled launch opportunities for Ares I-X for next week.

A team at the Kennedy Space Centre in Cape Canaveral, Florida is in charge of preparations for both the Atlantis and Ares I-X launches.

The development is part of the Constellation programme proposed by former President George W. Bush, with the goal of returning men to the moon by 2020 and eventually undertaking manned missions to Mars. The future of the Constellation, at least as originally envisioned, has been thrown into doubt by the findings of a commission of independent experts appointed by President Barack Obama to examine the programme.

Their summary report released in September suggest five possible options for the programme, but warned that continuing as planned would require $3 billion more a year in funding.

The full report is set to be released today, and the White House has yet to make any official announcement on the programme's future, but the Ares programme is proceeding despite the uncertainty.

The Atlantis is set to carry six astronauts to the ISS on an 11-day mission. The launch will be the fifth and last shuttle mission for this year.

There are just five more shuttle launches scheduled before the planned September 2010 retirement of the fleet.

But the White House could yet decide to extend the programme to 2011 to reduce US reliance on Russia's Soyuz craft for astro-naut transport to the ISS while the Orion capsules are being constructed.