Canadian Space Agency astronaut Steve MacLean seen here in 2006 before the launch of space shuttle Atlantis, is calling on all qualfied candidates to apply for two positions in the astronaut corps. ((Terry Renna/Associated Press))

Canadians and residents of Canada with science and engineering degrees or a licence to practice medicine might want to start checking the want ads Thursday, because the Canadian Space Agency is now accepting applications for the lofty position of astronaut.

It's only the third time since the creation of the Canadian Astronaut Corps in 1983 the agency has sought applicants, and comes after Dave Williams retired in the spring and Bjarni Tryggvason announced he would retire in June.

Astronaut Steve MacLean told CBC News the agency is encouraging people who are in good shape with at least an undergraduate degree in science or engineering and either work experience or a Master's degree or a licence to practice medicine to apply.

"If you have a minimum requirements, I really encourage you to apply and let us decide whether or not you are trainable," he said.

He said if previous recruitment calls are any guideline, the agency expects to receive between 5,000 and 10,000 applications and will whittle those down to 40 candidates who will go through aptitude and skill tests.

The minimum requirements also impose some physical restrictions as well, as applicants must have 20/20 vision with or without correction, good hearing, healthy blood pressure and fall within an average height range (from four feet, 11 inches tall to six feet, three inches tall).

Do you have the right stuff?

A look at the minimum requirements the Canadian Space Agency is seeking for two astronaut positions:

  • applicant must be a Canadian citizen or resident of Canada.
  • must hold a Bachelor's degree in Engineering, Applied Sciences or Science with two years professional experience, OR
  • a Bachelor's degree along with a Master's degree or a Doctorate in Engineering, Applied Sciences or Science, OR
  • Be licensed to practise medicine in a province or a territory of Canada.
  • Must be between 149.5 cm (four feet, 11 inches) to 190.5 cm (six feet, three inches) tall.
  • Must have visual acuity of 20/20 or better, with or without correction.
  • Blood pressure must not exceed 140/90 mm Hg (millimetres of mercury).
  • Must meet a standard of pure tone audiometry hearing thresholds.

MacLean said while many Canadians will meet the minimum requirements, the full list of assets an astronaut should have will make the final process a selective one.

"We need someone who is technically competent, someone who is operational under stress. We need an individual who is well-balanced and an individual who can be a leader sometimes and be a follower at other times. So it's almost magic that we're looking for," he said.

The agency is looking to fill two positions to bring the astronaut corps to six. After Tryggvason retires, the current corps of astronauts will be composed of MacLean, Julie Payette, Robert Thirsk and Chris Hadfield.

Once the candidates are selected next May, basic training will begin at NASA in August 2009, followed by training for missions of about six months.

MacLean also said the agency will likely keep 20 names on their list as other space programs develop and more opportunities arise.

Next year, Canadian astronauts Thirsk and Payette will be visiting the International Space Station, with Thirsk staying for a six-month period. But the agency has more in mind than sending astronauts to the station, as manned space programs around the world have begun planning towards new endeavours to the Moon and Mars.

The candiates who win the positions will likely be among the first astronauts to train aboard the U.S.'s new Orion spacecrafts, which will replace the aging shuttle fleet set to be retired in 2010, MacLean said.