A handful of Texas lawmakers want NASA to return to the moon and build an outpost on Mars even though the nation’s civilian space agency is struggling to complete the $60 billion International Space Station. The agency is adrift and needs to set far-reaching goals, said Rep. Nick Lampson, D-Texas, who is a senior member of the House Science Committee that has jurisdiction of National Aeronautics and Space Administration policy. Lampson’s legislation, which faces an uncertain future, would put the agency on a trajectory to build a reusable space vehicle capable of transporting astronauts to the moon and back within eight years and to Mars within 20 years.