Astronaut Jessica Meir will answer your questions on Tumblr

She'll begin at 4:30PM (Eastern time) today, March 11th.

James Blair/NASA

If you've got dreams of donning a spacesuit and going on trips outside the planet, don't miss Tumblr's Answer Time session today, March 11th. NASA's Jessica Meir will answer your questions starting at 4:30PM Eastern time, and it's a great chance to ask a real astronaut, especially if you missed Scott Kelly's Q&A session last year. Meir was part of the 21st NASA astronaut class in 2013 -- the first one that was 50 percent female -- and was cleared for actual missions in 2015, so you can ask her about what it's like to train for the job.

You can also ask Meir, a biologist who studied the physiology of animals in extreme environments, what it's like to be an aquanaut for NEEMO. The NASA Extreme Environment Mission Operations serve as testing ground for new equipment astronauts will use in space. She lived in an underwater habitat back in 2002 for the fourth NEEMO expedition and in a cave for a week last year for the ESA's Cooperative Adventure for Valuing and Exercising mission.

Meir wants to become one of the first astronauts to set foot on Mars and is now training for her first expedition. While you won't be hearing back from her until 4:30, you can send in your queries right now through NASA's Tumblr account (UPDATE: the submission page is now closed).