CAPE CANAVERAL, Fla. (AP) — Apollo 15 astronaut Al Worden, who circled the moon alone while his two crewmates drove around in the first lunar rover, has died at age 88. Family and friends said he died in his sleep at a Houston rehab center on Wednesday after treatment for an infection. Worden flew to the moon in 1971 along with David Scott and Jim Irwin. As command module pilot, Worden remained in lunar orbit while Scott and Irwin descended to the surface with the Apollo program’s first moon buggy. That was his only spaceflight. He was in NASA’s fifth astronaut class, chosen in 1966. Scott is one of four moonwalkers still alive. Irwin died in 1991.