In the coming decades, NASA is planning to send humans to Mars, but as psychology researchers are looking into what type of personalities will work well together, it seems like extroverts may cause some problems.

A round trip to Mars could take as long as three years, and a new study finds being an extrovert on long-term space missions could have disadvantages. Extroverts tend to be talkative, lively, easily bored, assertive, opinionated, and outspoken. If one person on a crew always wants to talk, while others are less social, “it could actually get pretty annoying,” study researcher Suzanne Bell, an associate professor of psychology at DePaul University in Chicago, told LiveScience.

The vehicles designed to travel to Mars are very tiny, and each person has little to no privacy. For the NASA-funded study, Bell and her colleagues reviewed previous research on teams who lived in environments similar to that of the Mars mission, including simulated spacecraft missions of more than 100 days and missions in Antarctica.

One virtual 520-day Mars mission isolated six volunteer astronauts for nearly a year and a half to simulate a mission to Mars and back to Earth. During this mission, an extroverted team member did not get along well with two of the other, introverted members. “They thought he was too brash, and would speak his mind too much, and talk too much,” Bell said.

If all goes as planned, and the extroverts aren’t too annoying on the way to Mars, what will they do once they arrive on the red planet? According to the Mars One website, the astronauts will be doing research, construction, and maintenance on the new settlement, and will have time to relax and enjoy activities down on Earth, like reading, playing games, watching TV, using the Internet, and contacting friends and family at home.

However, the astronauts will be surrounded by the same people and things that they may get bored. “People who are extroverted might have a hard time coping because they want to be doing a lot; they want to be engaged in a lot of things,” said study researched Shanique Brown, a graduate student in industrial and organizational psychology at DePaul. “And [on these missions], there won’t be that much to do — things become monotonous after a while, and you’re seeing the same people.”

Despite this new study, this does not mean extroverts can’t go to Mars. More research and space-simulation environment experiments need to be done to find the perfect balance of extroverts and introverts.

Whether you’re an introvert or extrovert, do you want to head to Mars? As long as you’re 18 or older, psychologically stable, physically healthy, and OK with possibly never returning to Earth, you can apply. Check out the rest of the qualifications for Mars One here.