a standard established in the 1951 case Dennis v. U.S. whereby the government could suppress speech to avoid grave danger, even if the probability of the dangerous result was relatively remote; replaced by the imminent Lawless action (incitement) test in 1969.
Laika became the first living being to orbit the Earth on Sputnik 2, Nov. 3, 1957. She died several hours into the flight from stress and heat. On May 28, 1959, rhesus monkey Able and squirrel monkey Baker became the first to successfully return to Earth after space flight.
Enos - The First Chimp in Earth Orbit. After the first successful flight of the chimpanzee Ham in Jan. 31, 1961 US Air Force wanted to further more investigate long-term impact of being in space. They did not want to endanger the life of human astronaut so they prepared another mission with a chimpanzee.