Solar plane pioneer prepares for US takeoff

The age of aviation adventures is back. Solar Impulse pilot André Borschberg hopes to join the ranks of Charles Lindbergh and Amelia Earhardt as his company seeks to make new flying records for its solar-powered airplanes. Their next adventure will be an intercontinental flight across the US, from San Francisco to Phoenix, Dallas, Atlanta, or St Louis, before landing in Washington DC, then taking off for their final destination, New York City.

Solar Impulse has already completed several record-breaking solar flights, including the first night flight and one across the Mediterranean Sea. The next big goal of the company is to fly around the world in 2015.

In this gallery, we'll take a look at the Solar Impulse planes, records, flight history, and how they fly.

The first night flight of a solar powered aircraft was flown by André Borschberg and lasted 26 hours, 10 minutes, and 19 seconds. Three world records were set, including one for altitude — 8,744 meters.

In 2010, the HB-H1B also flew from Geneva to Zurich, Switzerland.

As in the days of Charles Lindbergh and Amelia Erhardt, there's only room for one pilot in a solar plane. But who knows what the future will bring? Imagine what an airplane ticket would cost if airlines didn't have to pay for fuel? And just think of the environmental impact — plus the conservation of oil reserves — and less noise.

In 2012, the HB-S1A flew across the Mediterranean Sea. You can see it as it floats over the desert. 

A view from the top, where you can see the black solar panels.

 Solar Impulse's solar plane sits on the runway after its historic first flight in 2009.

Here's the nose.

The control panel in the cockpit can interpret data from the plane's flight and its condition, and communicate with the ground crew. It can control the power sent to the motors and monitor the battery status. 

The HB-S1A HB-S1B is powered by 10,748 solar cells on its wings and 880 on the horizontal stabilizer; the next model, HB-S1B, will have about 15,000 cells on top. Every cell is handmade before being sent to Solar Impulse,  where each is tested three times for voltage.

Cells are 135 microns and produce an efficiency of approximately 22.7 percent. Panels are made up of 300 cells that are cooked at 95 degrees for seven hours, then molded into the proper shape. The HB-S1B will be powered by 48 panels.

The types of energy produced to power the solar plane include photic, electrical, the batteries, and the motors, chemical, potential (when the plane gains altitude), mechanical, and kinetic. Energy losses through friction and heating are minimized as much as possible.

This shows the wing span, 63.4 meters (208 feet) compared to a Airbus 340. Its length is 21.85 meters (71 feet), and height is 6.4 meters (20 feet). It runs on four brushless motors with 10hp per motor. The HB-S1B is powered by 10,748 solar cells on its wings and 880 on the horizontal stabilizer. It takes off at 44k/h (27mph), flies at 70k/h (44mph), and has a maximum cruising altitude of 8,500 meters (27,000 feet).

The first significant solar-powered flight was in 1981, when Paul MacCready's US team developed the Gossamer Penguin, and then the Solar Challenger. They flew across the English Channel with a maximum power of 2.5kw. At the same time in Europe, Günter Rochelt developed the Solair 1, which was powered by 2,500 photovoltaic cells and produced up to 2.2kW.

Couldn't resist adding this photo. The Solar Impulse and solar flight is very popular.