With a green light from Congress, NASA is moving swiftly to carry out President Bush’s ambitious plan to return robots and humans to the moon and eventually to Mars. The United States is also seeking foreign partners for the hugely expensive project, hoping to save money and avoid wasteful duplication. Space officials from 17 countries, including China, Russia, Japan and much of Europe, participated in a planning workshop in Washington last week. Representatives from each nation said they intend to participate in at least the planning phase.