For NASA's 2017 astronaut class, 18,300 people have applied
to join which is thrice the number that had applied for admission to its class
in 2012.
Earlier such a record was set up in 1978, where 8000 people applied, most probably inspired by the release of 'Star Wars' in 1977.
From December 14, 2015, the American Space agency had invited applications for its astronaut classes which ended on February 18, 2016.
There is no specific time as NASA opens applications on an as-required basis and this time it used social media to promote the opening.
It is a long procedure to select 8-14 candidates who will face NASA's Astronaut Selection Board; generally it takes around 18 months.
The candidate's initial selection will be around mid 2017 and those clearing the board will have to go through two years of rigorous astronaut training on space craft systems, space walking skills and teamwork, along with other requisite skills.
After this, they will be assigned to one of the four different space crafts, including the International Space Station, NASA's Orion spacecraft, or one of two commercial spacecrafts currently in development: Boeing's CST-100 Starliner or the SpaceX Crew Dragon.