President Bush has not decided on his vision for the future of human spaceflight, the White House said Thursday, shooting down reports that an announcement was imminent on plans to return to the moon and send explorers to Mars. “It would be premature to get into any speculation about our space policy,” White House spokesman Scott McClellan said at his daily briefing. “It has been, and continues to be, under review. There are no plans for any policy announcements in the immediate future, and that would include any upcoming speeches.”