Walter Cunningham, the last surviving astronaut from the first successful crewed space mission in NASA's Apollo program, died Tuesday in Houston. He was 90. NASA confirmed Cunningham's death in a statement but did not include its cause. Spokespersons for the agency and Cunningham's wife, Dot Cunningham, did not immediately respond to questions. Cunningham was one of three astronauts aboard the 1968 Apollo 7 mission, an 11-day spaceflight that beamed live television broadcasts as they orbited Earth, paving the way for the moon landing less than a year later. Cunningham, then a civilian, crewed the mission with Navy Capt. Walter M. Schirra and Donn F. Eisele, an Air Force major. Cunningham was the lunar module pilot on the space flight, which launched from Cape Kennedy Air Force Station, Florida, on October…