Washington: Yuri Gagarin and Neil Armstrong are names printed in bold in the history books. But two smaller, unknown space pioneers who helped make their advances possible had their first flight 50 years ago.
Two monkeys were shot into space by the US space agency NASA on May 28, 1959 -- paving the way for humans, like the Russian who became the first man to orbit the Earth and the US astronaut who was the first to set foot on the moon.
Rhesus monkey Able and squirrel monkey Miss Baker were the first animals to be launched into space and return home alive, giving US scientists valuable clues about the effects of weightlessness.
On their big day, the animals, each about the size of a cat, were strapped into a Jupiter AM-18 rocket and shot 500 km into space from Cape Canaveral, Florida. The monkeys successfully completed their flight two years before Gagarin circled the globe.
The space race between the United States and the Soviet Union saw the Russians rely most on dogs for their non-human space tests. The dog Laika aboard Sputnik 2 was the first animal to orbit the Earth in 1957 but perished during the flight.
Able and Miss Baker's rocket flew 2,500 km and landed about 15 minutes after takeoff on the Caribbean island of Antigua.
Jim David, a curator at the Smithsonian Air and Space Museum in Washington, called the moment an important step in the US space programme. At that time, information about the effects of weightlessness was in short supply, he said.
The animal astronauts were able to appear at the subsequent press conference, but Able would soon pay a steep price for her trip to space. An electrode that had been implanted under her skin got infected and had to be operated on. She died on the operating table.
The monkey was stuffed and now reminds visitors of the achievement at the Air and Space Museum, strapped into the capsule in which she travelled to space. In 1985, the US animal space flight programme was discontinued. Though NASA no longer sends monkeys aloft, it still conducts some experiments with small animals.
Today, animal-rights activists find the scientific efforts of the early space age unacceptable.
The way monkeys were strapped into a capsule was "unbelievably brutal", said Kathy Guillermo, vice president of animal rights organisation PETA.
In contrast to Able, Miss Baker was able to enjoy her fame, even visiting the White House and receiving buckets of fan mail. She died in 1984 at the age of 27 and was buried at the NASA Marshall Space Flight Centre in Huntsville, Alabama.