An unusually populist comedy for a director of such normally refined tastes, this geriatric space adventure from Clint Eastwood spoofs the aging of the Baby Boomer generation with broad appeal, but flags in its poorly structured third act. While Space Cowboys gets off to an interesting start in a flashback sequence that casts lookalike actors with their voices dubbed by the film's stars, the story's central conceit (four aging would-be astronauts getting one last chance to blast off) is exhaustively rehashed, making for a tiring set-up. Once the quartet of creaking seniors is in training for their mission, however, the film finds its legs and purpose, sending up the idea of vitamin-popping oldsters rediscovering their right stuff with zeal and relish. When its characters finally achieve orbit, the film loses its way again, stumbling with a subplot involving an egotistical young colleague who botches a job and the unexpected illness of a central figure. Nevertheless, Space Cowboys is about two-thirds of a fine and enjoyably risible comedy that is a bounce back for Eastwood after stumbling badly with his last directorial effort, True Crime (1999).