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.
By December 1958, the Americans had sent a living creature into space and in May 1959 monkeys Able and Baker became the first animals to survive the trip. Yet these early American achievements were eclipsed on April 12, 1961 when the Soviet Union put the first human, Yuri Gagarin, into space.