Johnson Space Centre staff in Houston marked the 35th anniversary of the first manned lunar landing with a vintage car parade and proud reflections of a deed that dazzled the world.

Confined to their orbiting capsule at least until April in the wake of the Columbia accident, the three men aboard the international space station are putting a brave face on their predicament.

A Russian space official today said US manned space flights could be grounded indefinitely following the loss of the shuttle Columbia and suggested that Russian Soyuz rockets should be used to ferry crews back and forth to the International Space Station, a news agency reported.