Whether you're an astronaut or a small business owner, our bodies all react to fear and pressure in similar ways.

Consider this story, from 1962: Flying 81,000 miles in just under five hours, astronaut John Glenn was the first American to orbit the Earth. But fear quickly spread among ground control as a signal indicated the spacecraft's heat shield had become detached, which would have killed Glenn instantly upon re-entry.

Thankfully, it was a false alarm. But what's even more impressive? Even in the face of a dangerous, life-threatening event, when Glenn landed, his blood pressure was just barely higher than it was before he left the ground.

While most people will never be faced with a challenge like Glenn was, the way he and every other astronaut since 1962 has trained for dangerous missions is a strategy anyone can copy to calm their nerves before a more common stressor-- a critical presentation or job interview.

Ozan Varol is a former scientist on NASA's Mars Rover program and author of the bestselling book, Think Like a Rocket Scientist. During a recent conversation about his book, Varol told me that astronaut-training strategies can improve a person's confidence as a public speaker while minimizing the chance that something could go wrong. 

Here are his best tips on how to stay calm and put your best foot forward.

Simulate the Event in Real-World Conditions

Varol explains that by the time astronauts fly on their mission, they have flown the same route countless times on simulators. These simulators are designed to look and feel exactly like the control panels astronauts will see on the actual spacecraft. 

Astronauts like to say, "test as you fly." Similarly, Varol's recommendation is to simulate your next pitch, presentation or job interview. Mimic real-world conditions so you know what it'll feel like the day of.

For example, if you have an upcoming virtual presentation, dress up and deliver your presentation in the same room and with the same computer equipment that you will use on the day of the event. Record it and play it back. How do you come across? Are you fidgeting excessively or looking away from the webcam? You can even invite a peer or family member to watch it live to increase the stress of the real event.

Build in Redundancy

In aerospace, redundancy refers to backups. Spacecraft are designed to operate even when things go wrong. "To fail without failing," says Varol.

Just as a car comes with a spare tire, your presentation should have a back-up in case something happens to the system.

For example, when I'm asked to deliver a keynote, especially in a virtual setting where platforms and WiFi connections are unreliable, I always send the same deck to the host of the event. If I can't share my desktop or my video is unstable, I can ask the host to advance the slides.

I take it one step further. Although I design presentations in Apple Keynote, I convert the deck to a PowerPoint that anyone can play on a PC or a Mac. It's another redundancy in case the host only has one system that is not compatible with my presentation. 

Even if you never use your backup, simply having it available will help you focus on your message and not on worst-case scenarios.  

Leveraging rocket-science preparation for any pitch, presentation or public-speaking opportunity will calm your nerves and boost your confidence.