Opinion: I’m an astronaut. Here’s what I can tell you about what you’ll experience in the Mars simulator for a year

NASA has put out a call for applicants to apply to be test subjects for an upcoming human space exploration Mars study that will last for a full Earth year. Is this something you would like to do?

It’s a compensated position, but what’s a year of your life worth? That should be your first question. And there are lots of other details to work out before you disappear for a year.

Leroy Chiao - CNN
Leroy Chiao - CNN

I know something about being deployed on a NASA vessel for months at a time. For my longest mission on the International Space Station (ISS), I was gone for 193 days, from October 2004 to April 2005. That doesn’t count the two months I spent in Russia to finish my training before the launch, and two weeks after my return to Earth before I was finally able to get back home to the US.

This upcoming Mars simulator mission won’t require that you be astronaut-ready. In fact, the requirements are fairly broad: You need to be a healthy, non-smoking US citizen or permanent resident between the ages of 30 and 55 and proficient in English. You’ll also need to meet certain STEM requirements or have the requisite military experience or have 1,000-plus pilot flight hours.

One thing to consider before you take part in simulating being on the Red Planet is what happens to your possessions back home as an Earthling. Who is going to take care of your stuff? Who’s going to help pay your bills? NASA doesn’t really help sort out those sorts of life issues.

During my monthslong space mission, I was able to put everything on autopay on my credit cards or through my credit union. The grass at my home was cut by a lawn service — I paid them an average amount monthly and squared up with them after my return. It was all manageable.

Another thing is what you are — and aren’t — going to be allowed to take with you.

In space, we were allowed to bring a few personal items like photographs. On the ISS, I wore my own personal wristwatch that has been with me on every mission. You can’t bring your own phone, however, or even your own camera. And when you’re on the ISS, NASA wants every photo that you take!

The four test subjects who will be part of the year-long Mars simulator experiment will live and work inside a 1,700 square-foot 3-D printed habitat at NASA’s Johnson Space Center for this Crew Health and Performance Exploration Analog (CHAPEA) study.

This won’t be the first such effort, however. In fact, one study currently underway is scheduled to end in June after 378 days. The individuals taking part simulated many aspects of a real Mars mission, including nominal operations, malfunction and failure cases, ventures outside of the habitat for simulated space walks.

One of the main goals of these missions is to study individual and crew dynamics, and to see how they perform under stress. Space may seem like a quiet and placid environment, but performing a busy schedule of experiments in close confines can indeed be stressful. And understanding how a crew reacts to the challenges of a deep space mission is the point of this exercise, to a large degree.

What if you get part way through the experience and can’t take it anymore? This is another question you’d want answers to before signing up. The answer would be easy if you were really going to Mars, or even to the space station. Once you’re onboard, there’s no going back.

One thing that kept us going on the ISS during long missions was that we were in frequent contact with friends and family on the ground. When I was there, even before live internet access was available on board, we would still get email synchronizations about three times during a 24-hour period.

There was and still is a VoIP phone (Voice over Internet Protocol), a technology that allows you to make voice calls via broadband internet instead of over an analog phone line onboard the ISS, so astronauts can make short phone calls to people on the ground when the antenna is pointed at one of the satellites.

With a Mars simulation (or on a future Mars mission, for that matter), there would be a communication delay of between three to 20 or so minutes because of distance, so real-time communications would not be practical.

Also, I doubt there will be internet connectivity during the year, so don’t count on doing any web surfing. The ground crew can still send things to you, and you can send things back, but it won’t be like being at home on your laptop.

One more thing: Onboard the ISS, our favorite thing to do when we had any free time was to look out of the windows and take photographs of our beautiful home planet. While there will be windows on a Mars spacecraft, pretty quickly the Earth will turn into a star and you won’t be able to see much because the sunlight — which you will always be in — washes out the starlight and all you see around you is black.

On the simulator, there likely are no windows at all, to make it more isolating. Are you the type that can be in a windowless enclosure for long periods of time? I suppose that you would at least have movies and photos on your laptop. That would help, but it obviously wouldn’t be the same.

How did I manage being in close confines with a handful of other people over an extended period of time? Well, the ISS is bigger that the Mars simulator. But once you set your expectations about the limited space you’ll have and the protracted period of time you’ll be gone, you’ll probably be fine. And as far as getting homesick, you might not find the time to be. After all, most days you will be very, very busy — and that’s a good thing. In fact, it would be awful to have too much free time!

How would this experience change you? Spaceflight — especially long-duration spaceflight — has an effect on all astronauts, and it is generally a positive change. Many of us go through a recalibration of perspective, taking a “bigger picture” outlook on life. But some astronauts do have “reentry” problems that they have to work through.

For example, some astronauts need time to adjust to being In crowds again or even being around their own small children. These are generally short-term issues, but it is still something to think about.

Finally, in your year on board the Mars simulator, you will very likely miss some of the things that I missed most. Other than family and friends, with whom I had pretty good contact, mostly through email, I missed nature. I missed feeling the wind on my face, watching birds flying, squirrels running around.

As soon as the spacecraft hatch was opened after landing from my ISS mission, I smelled grass. It was a wonderful smell and it brought back a flood of memories . I knew I was back on Earth. I knew I was home.

If you still decide to apply and get selected, you may feel the same way after your long mission, even though you’ll never leave the ground. And if you do get chosen and decide to take part in this simulation, good luck!

For more CNN news and newsletters create an account at CNN.com