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Why Is Solar Impulse Waiting For The Epic Adventure Of A Lifetime?

Originally published on 1Sun4All.

You may have seen one of my recent articles about the impending solar flight across the Pacific Ocean: The Moment Of Truth for Solar Impulse: Epic Pacific Crossing or Solar Impulse Prepares for 5 Days & Nights Pacific Crossing, and you may be wondering why Solar Impulse 2 (Si2) has been waiting to make this first-ever journey. Si2 recently provided an outline of the conditions the team is waiting for. Enjoy!

Why We Are Waiting

The Mission Engineers in Monaco Mission Control Center are working hard to find the good-weather window for a 5-day and 5-night crossing from Nanjing to Hawaii. Different routes are being analyzed. 4 main conditions have to be fulfilled in order to have a green light for takeoff:

1. Maximizing energy management

  • During the day: clouds can limit the amount of energy we receive and must be avoided
  • At night: to avoid flying in clouds, #Si2 might have to fly higher and therefore use more energy (air is less dense)
  • When the sun comes up: in the morning we need perfect sunny conditions as the batterystate of charge will be dangerously low after the night.

Solar Impulse

2. Maximizing flight duration

  • Crosswinds: they can extend the duration of the flight by slowing the plane, adding another night challenge for the plane and pilot
  • Tail winds: the jet stream can shorten the duration of the flight by carrying #Si2 faster through the air

Solar Impulse

3. Allowing the pilot to rest

  • Turbulence caused by bad weather conditions won’t allow the pilot to rest
  • An active night, fighting for energy by constantly changing flight levels and directions, won’t allow the pilot to rest

4. Finding the right takeoff and landing conditions

  • Takeoff: even if the overall window is good, bad weather at departure point can make the window unsuitable
  • Landing: forecasting the touch-down condition 5 days in advance is a challenge, adding more suspense to the crossing…

Join the Movement: #FutureIsClean

solar impulse cartoon

Would you like to meet the Si2 team? Check out the new website team page!

Illustration Credit: Solar Impulse | Cartoon Credit: Martin Saive via Solar Impulse 

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Written By

-- I am an artist, painter, writer, interior designer, graphic designer, and constant student of many studies. Living with respect for the environment close at hand, the food chain, natural remedies for healing the earth, people and animals is a life-long expression and commitment. As half of a home-building team, I helped design and build harmonious, sustainable and net-zero homes that incorporate clean air systems, passive and active solar energy as well as rainwater collection systems. Private aviation stirs a special appeal, I would love to fly in the solar airplane and install a wind turbine in my yard. I am a peace-loving, courageous soul, and I am passionate about contributing to the clean energy revolution. I formerly designed and managed a clean energy website,


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