May 5 (UPI) --President Donald Trump on Monday celebrated National Astronaut Day on the 64th anniversary of Alan Shepard becoming the first American to go into space. On May 5, 1961, Shepard's Freedom ...
Developed together, the twin Mariner 1 and 2 spacecraft were based on the Ranger lunar probe and planned for a joint mission to our closest neighboring planet. The probes featured seven instruments ...