SWITZERLAND. On June 2 the Solar Impulse 2 plane — the first to fly around the world on just solar power — successfully completed its maiden flight with test pilot Markus Scherdel. In April 2014, as I witnessed the plane’s unveiling, I realized that “being in the presence of greatness” was the simplest and most perfect way to describe my emotions. There in the hangar in Payerne, Switzerland, the view of SI2 was overwhelming: a monument of history in the making. The plane itself is a marvel of technology and engineering — a wondrous sight — that through the human touch really reveals its grandeur.

Bertrand Piccard and André Borschberg, the two luminaries behind this achievement, are working to complete this mission with a multidisciplinary team of 80 specialists, 90 partners and about 100 advisors.

The initiator and pilot of Solar Impulse, Bertrand Piccard, is also a psychiatrist and a member of the Swiss Medical Hypnosis Society. With Brian Jones, he completed the first non-stop balloon flight round-the world in 1999. In 2003 Piccard teamed up with pilot, engineer and MIT graduate in management science, André Borschberg, in co-funding the Solar Impulse project.

In 2010, André Borschberg accomplished a feat. For the first time ever, he completed a 26-hour flight in a solar plane. It was the first night flight for the Solar Impulse. Later, in 2013 the plane flew a multi-staged journey across the United States.

The SI2 carbon fiber plane has 17,000 solar cells that power up four electric motors and recharge lithium batteries during the day that allow the airplane to fly at night. It has the weight of a car and it can reach a cruising altitude of 8,500 meters. With a wingspan of 72 meters — 9 meters longer than the first solar impulse plane — Bertrand Piccard often compares it with Disney’s character Dumbo the flying elephant. It’s a comparison that refers beyond the plane’s appearance to the ridicule and opposition the project faced early on.

Flying SI2 is not like flying a regular aircraft. Previously, the pilots used self-hypnosis and meditation techniques that allowed them to maintain their concentration on long flights, in an unpressurized, unheated cockpit with extreme temperatures of -40 to +40 Celsius degrees. This time, the SI2 has a “virtual” co-pilot monitoring their alertness.

Here, André Borschberg and Bertrand Piccard answer a few questions regarding their ambitious project and its challenges.

What’s the plan for the round-the-world trip? How many days in total, how many legs?

Solar Impulse: The round the world will last 20 flying days, over four months. The attempt to make the first round-the-world solar-powered flight is scheduled to start in March 2015 from the Gulf area. Solar Impulse will fly, in order, over the Arabian Sea, India, Burma, China, the Pacific Ocean, the United States, the Atlantic Ocean and Southern Europe or North Africa before closing the loop by returning to the departure point. Landings will be made every few days to change pilots and organize public events for governments, schools and universities.

As pilots, how do you prepare for more than a five days non-stop flight, how do you prepare for something that has never been done before?

André Borschberg: We both took up the challenge of staying at the controls of the flight simulator for an uninterrupted period of 72 hours needed for a virtual crossing of the Atlantic. To draw all the lessons from this experiment and measure our mental and physical states in real time, a whole battery of tests was performed by the Solar Impulse team in cooperation with experts in every field. Fatigue, cockpit ergonomics, nutrition, use of the toilets, exercises to prevent thrombosis, vigilance and the ability to pilot the aircraft in a state of sleep deprivation were all assessed.

Then the preparation will be followed by a program of test flights and training in Payerne airfield (Switzerland) in order to learn how to fly the new airplane. Due to its immense size and its extreme lightness, Solar Impulse 2 is very sensitive to turbulence and wind during take-off and landing. This spring, we will also realize a virtual round-the-world flight through simulation, in order to know if we will be able to maintain the aircraft in good weather conditions.

Tell us something about the “virtual” pilot; what’s the exact role? When and how will you use it?

Solar Impulse: Without the Stabilization Augmentation System, the round-the-world airplane wouldn’t be able to fly several days in a row. Comparable to a classic autopilot, a new function is embedded in this system, the Monitoring and Alerting System, which is designed to monitor the airplane, the pilot and the auto-pilot while detecting anything abnormal or beyond the safety limits.

In terms of communication, what is the upgrade from a normal aircraft?

SI: The communication device transmits over 100 values of data to the mission room, from temperature of the motors to the position of the aircraft and tension in the accumulators. Weighing less than 5 kg (11 lbs) with an energy consumption not exceeding 50 watts, this solution is the pilot’s lifeline to the ground and a great tool for fans to feel part of the adventure.

Let’s fast-forward in time: after SI2 completes the task of flying around the world, what’s the next step? Will it be a non-stop SI flight, will it be a passenger SI? Or will it be something else?

SI: We will surely see small solar seater planes soon. However, we do not foresee solar-powered commercial aircraft in the near future, but we must remember the past anyway. In 1903, when the Wright brothers succeeded in flying their airplane over a distance of 200 m, could you imagine that 24 years later Lindbergh would cross the Atlantic Ocean? He was alone on board and 30 years later airliners would carry 200 passengers, completing the same journey in eight hours while two men walked on the moon!

Our primary purpose is not to revolutionize aviation, but the way in which people think about energy and clean technologies. If Solar Impulse technologies were used on a massive scale, the world would be able to save up to 50% of the current consumption of fossil energy and produce half of the rest with renewable energies. As for the aviation industry, it is well aware of its need to change. However, this cannot be done quite as drastically as with Solar Impulse. Our project involves zero fuel. Conventional aviation cannot switch straight to zero fuel. Intermediate steps are needed, such as using lighter materials, more direct routes or approaching airports through constant descent rather than performing level landings. Aviation will be the final area of transport able to stop using fuel.

Bertrand, obviously you used some of your previously gained knowledge, as a psychiatrist for example, on these flights. You also used the metaphor of dropping off the ballast in order to gain altitude. How do you keep the knowledge and drop off the prejudice that comes from it, or as we in academia so proudly call it, the skepticism?

Bertrand Piccard: Solar Impulse has brought about technological innovation and captured the attention of millions of people around the world. We are doing something many thought was impossible with solar energy. This is only the start of something bigger. If nobody put into question your project, it clearly means that it is not ambitious enough.

This ambitious project is one step closer to its goal with the two-hour-and-seventeen-minute first flight and many ground tests. A number of flights will be performed this summer before the round-the-world trip. To find out more about the story and to stay tuned to the solar impulse adventure, visit the solar impulse website and their Twitter.