The European Space Agency says it it "thrilled" by the number of people who have applied to join its astronaut corps.
A total of 22,589 individuals filled out the online form - two-and-a-half times the interest level when Esa last ran a competitive process in 2008.
There was also a sizeable jump in women wanting to go into orbit - 5,419 applications this time compared with only 1,287 last time.
Appointments should be made in 2022.
"Having more than 22,000 applicants is quite a number," said Josef Aschbacher, Esa's director general.
"We have all been astonished. For me, it is a very strong expression of interest and enthusiasm that people have across Europe in space, and in becoming an astronaut.
"I'm extremely thrilled by these numbers; it's just amazing."
Esa says it will give contracts to between four and six individuals to join its astronaut corps on a full-time basis. But it plans also to recruit a reserve of up to 20 persons who will be held on standby in case other opportunities emerge.
One such opportunity might include a member state of Esa wishing to fly a "national mission" outside of the usual arrangements the agency has with its partners on the International Space Station (ISS).
This would see that member state purchase a seat to fly its citizen on one of the new commercial capsules now available, with Esa then managing all of the training.
David Parker, Esa's director of human and robotic exploration, said he was particularly pleased to see the numbers applying to join a feasibility study that would look at how to fly an astronaut with a physical disability.
"We didn't really know what the response would be to this particular call. Would we get applications for this position to work with us on preparing the road for a person with a physical disability to fly to space? That question has been answered now with an impressive 257 applications, and 60 of them are women. That's really exciting," he told reporters.
The largest number of applications came from France - 7,137. That's perhaps not surprising given that French national Thomas Pesquet is currently aboard the ISS. There is huge media coverage in France about his mission.
The next largest group of applications came from Germany (3,700), the UK (1,979), Italy (1,860), Spain (1,344) and Belgium (1,019).
"The next phases of the selection process foresee the psychological tests, followed by practical and psychometric tests. Then there will be the medical selection, followed by two rounds of interviews. So it is quite a lengthy process," explained Antonella Costa, who works in human resources at Esa.
Screening of the application forms will probably permit at least 1,500 candidates to begin this process.
Esa currently has seven active fliers on its books: Luca Parmitano and Samantha Cristoforetti (Italy), Alexander Gerst and Matthias Maurer (Germany), Andreas Mogensen (Denmark) and Timothy Peake (UK).
Six have been to orbit at least once (Maurer will get his first chance in October). Mogensen and Peake are awaiting the announcement of their second flight opportunity - likely to be in either 2024 or 2025.
Cristoforetti will become the first European woman to command the space station when she returns to the orbiting outpost next year.
The vast majority of those who applied for the next class will inevitably be disappointed but Esa urged everyone to think about taking other roles within the agency.
There is a retirement wave coming that will see Esa having to recruit something like 500 new staff members over the next five years.
"I would encourage people to think about Esa beyond just astronauts. Astronauts is a very visible programme, it's a dream job - but we are about a lot more than astronauts. And there will be a lot of very, very interesting opportunities to join Esa in other capacities in the coming years," said Lucy van der Tas, the head of talent acquisition at Esa.