In one year, the 52-year-old man grew two inches. In two days, he shrunk back down to his original height. Nope, he's not a freak of nature. He's the astronaut who just got back from 340 freaking days in space.

On March 1, NASA astronaut Scott Kelly returned safely home after a year-long mission on the International Space Station. He has seen 5,400 earth orbits, nearly 11,000 sunsets and completed two spacewalks.

The main purpose of his mission? To offer himself as a specimen for NASA scientists to analyze the effects a year in space has on the human body and mind. They will also observe how Kelly re-adapts to Earth over the next year. These findings will be crucial to understanding how to prepare humans for space travel to Mars -- or to determine if our bodies can even handle going.

With so much focus on Kelly's mission and all that he's accomplished in the past year, here are a few takeaways from his experience that you can apply to making it as an entrepreneur. 

1. Accept the weight of enormous unknown risk

Though many of the risks of hanging out in space for extended periods of time are known -- exposure to radiation, vision loss and a whole host of other adverse effects on the body -- many are not. No American astronaut has ever logged this many consecutive days in space.

"Such an undertaking requires equal parts optimism and resignation," wrote Chris Jones in his epic Esquire Classics piece on Scott Kelly titled Away. To accept the mission to live a year of your life in space, you must accept that to a certain extent, you don't know what's gonna happen. And that you will have to take those challenges as they come.

Again, from Chris Jones' piece:

"Scott is highly adaptable and highly resilient," says Al Holland, a NASA psychologist who has tested him extensively. He is some rare combination of grit and give.

You can certainly anticipate challenges of running your business beforehand. Yet there's still heaps of unknown risk. Until you get in there and start doing the dirty work of entrepreneur-ing, you won't know what your real challenges might be or how you might overcome them. There's only one way to find out. Get to it.

2. Remember: Small steps before giant leaps

Incremental steps are crucial to accomplishing any huge feat, be it in sending humans to Mars or being the first to market with disruptive technology.

Everyone's itching to get to Mars ASAP, which is exactly why NASA launched this one-year mission. Previously, long-term missions to the International Space Station were limited to six months, which isn't long enough to understand the long-term effects that space travel has on the body. (Mars missions are projected to last two and a half years.)

Even to be qualified for this 340-day mission, the chosen NASA astronaut needed to have already logged a significant amount of time in space. A veteran of three previous missions to the International Space Station, Kelly proved he had the chops, stamina and skills to survive a year holding down the fort at the International Space Station.

Though you've got huge game-changing ideas, keep in mind all the necessary stages to get there. Learn from your beta launch. Start with test markets before a massive rollout. Get feedback from early users before pushing your product to the entire world.

3. Take your exercise regimen very seriously

It's no surprise that  exercise makes you smarter, happier and less stressed -- all positive benefits for entrepreneurs. For cosmonauts, exercise is far more serious business. Over the last year, Scott Kelly has biked, run and strength trained for about two hours a day. Nearly every day. For 340 days.

When the body isn't working against gravity, your bones and muscles get weaker. Astronauts lose on average 1.5 percent of their bone mass per month in space. Their  aerobic capacity drops by almost 20 percent. Missing those workouts would have been detrimental to Kelly's health and ability to perform his spaceman duties, especially in the event of an emergency.

Take a page out of Kelly's book and prioritize exercise not only for your own health, but also the health of whichever entrepreneurial mission lays ahead of you.

4. Be prepared for lots of unglamorous work

Think your day-to-day as a startup CEO is hectic? Try being one of two guys responsible for conducting almost 400 experiments in the span of a year -- oh, and without gravity. Kelly and his Russian counterpart Mikhail Kornienko were insanely busy during their 340-day trip away from Earth.

They had to tend to not just important investigations and experiments in the name of science. With only two full-time on-site staff, there's no outsourcing the un-fun International Space Station maintenance work to your virtual assistant. Whether the ammonia cooling system needs reconfiguring or the space toilet has sprung an unfortunate leak, it's on you to fix it.

Sure, as job in space travel or a running fast-growing startup seems glamorous. But the astronauts and the entrepreneurs behind the scenes know the nitty gritty work required.

5. Build an all-star team

All eyes are on Kelly because he just spent 12 whole months in space. But he was only one of many NASA scientists, engineers, astronauts and crew members who contributed to making the one-year mission a success.

"Teamwork makes the dream work," Kelly said during a press conference in Texas yesterday. "This is the biggest team sport there is. Space flight It's about all of us, not just one person."

Likewise, any entrepreneur who thinks she can build and launch a successful product on her own is in for a rude awakening. Even if you have the vision, you can't execute every single detail. Whether you're launching a rocket ship to space or a new startup, you need a gangbusters team of brilliant minds to make it happen.

6. Enjoy the ride and share the wealth

Millions of people dream about going to space one day. Millions more wish they could ditch the 9-to-5 and become entrepreneurs. The percentage who actually make it in either career is small.

If you're lucky enough to have landed either gig, take a minute to appreciate how lucky you are. Express your gratitude (which has  scientifically proven beneficial effects.) And enjoy the amazing moments this lifestyle offers you.

Over the past year, Scott Kelly has been documenting his journey on Instagram and Twitter.


Despite being insanely far from his friends and family and missing out on an entire year of Earth life, he found numerous opportunities to appreciate the gloriousness of space and share it with millions of people down below who will never be able to blast off into the stars.