Canadian astronaut job postings don't come up very often. So if you were thinking of applying for this year's rare opportunity, don't miss today's deadline.

The Canadian Space Agency is accepting applications until 23:59 PT tonight — that means most Canadians will have until the wee hours of tomorrow morning to finishing submitting their applications online.

Be a Canadian astronaut - this is the last weekend to apply. Don't miss your rare chance! <a href="https://t.co/Gnz8w9Sizu">https://t.co/Gnz8w9Sizu</a> <a href="https://t.co/Jem59QnHbB">pic.twitter.com/Jem59QnHbB</a> —@Cmdr_Hadfield

If you're looking for some last-minute advice about how to polish up your application, check out these tips from Chris Hadfield, who served as the first Canadian commander of the International Space Station during a 21-career as an astronaut.

The competition this year will be tough. The astronaut recruiting campaign was first announced on June 17. Within a month, 3,372 Canadians had already applied for just two positions.

Want to know who you're up against? CBC News has profiled some impressive candidates from across the country, many of whom have been working for more than a decade to gain the qualifications and experience to give them a good shot at being chosen, from degrees at the International Space University to private pilot and dive training.

Over the course of the next year, the pool of applicants will be whittled down to a short list of 200, then 40 finalists, following a series of written, physical and mental tests, along with interviews and security clearances, before the two successful candidates are announced.

The last time Canada recruited astronauts was in 2008-09. The successful candidates, David Saint-Jacques and Jeremy Hansen, have completed their training. Saint-Jacques is scheduled to blast off into space for the first time in November 2018. Hansen is expected to fly by 2024.