According to the US DOE the next step is to equip the plane with lithium ion batteries so it can continue to fly at night. Of course the plane cannot fly continuously without batteries as the sun will set. This is because the earth spins far faster than the plane flies. The earth spins at about 1,000 miles per hour and the plane only races to the spectacular speed of 45 miles per hour. The plane could fly continuously above the Arctic Circle in the summer. Perhaps the best use for this plane should be for the Hollywood remake of “Stop the world I want to get off”.
Here are the specifications of the plane:
Wingspan 63.40 meters
Length 21.85 meters
Height 6.40 meters
Motor power 4 x 10 HP electric engines
Solar cells 11,628 (10,748 on the wing,
880 on the horizontal stabilizer)
Average flying speed 70 km/hour
Maximum altitude 8,500 m (27,900 ft)
Weight 1,600 kg
Take-off speed 35 km/hour
Here is the news provided by the US DOE
“A solar-powered aircraft took its maiden flight on April 7 in Switzerland, achieving the latest milestone in a project that aims to launch a zero-emission flight around the world in 2012. Solar Impulse HB-SIA, a lightweight prototype with the 208-foot wingspan of a Boeing 747-400, climbed to just under 4,000 feet during its 87-minute flight. The aircraft has nearly 12,000 silicon mono-crystalline solar cells on its wings and on its horizontal stabilizer, and those solar cells provide power to the craft's four electric engines. A test pilot put the craft through a series of maneuvers before safely landing the Solar Impulse at an airstrip. Solar Impulse chairman and co-founder Bertrand Piccard noted that the project had taken an important step with the recent achievement, although the team still has far to go before it is able to fly a craft all night in preparation for the around-the-world flight.
Piccard, who was the first to pilot a balloon non-stop around the globe, initiated the Solar Impulse Project in 2003. The co-founder has since been joined by a team that includes multi-disciplinary scientists and advisers from a number of countries. In December 2009, the Solar Impulse completed a short inaugural takeoff-and-landing at an airport in preparation for this initial extended flight. Solar Impulse backers plan further testing of this model, which relies on minimal instrumentation and an unpressurized cabin. The next major goal is to make a 36-hour flight, which would require the addition of lithium-polymer batteries for night flight. Following that, a second aircraft, Solar Impulse HB-SIB, will be developed to attempt several consecutive 24-hour flight cycles. Success in those trials would enable the Solar Impulse to attempt its first trans-Atlantic crossing, currently scheduled for 2012. Meeting that benchmark would clear the Solar Impulse for an around-the-world solar journey.”