Solar Race Around The World

Story he
http://www.businessweek.com/innovate...508_074303.htm

Aircraft information:

http://www.solar-impulse.com/scripts/page7203.html

Objectives and main stages
The challenge consists in conceiving an airplane capable of taking off
autonomously, then climbing to an altitude of 12,000 metres, and
maintaining its flight for several days with no fuel, propelling
itself by means only of the solar cells mounted on its wings. In
addition, it will have to use the energy accumulated during the day,
not only to maintain its flight, but also to recharge its batteries
and to ensure its flight at night. The pilot must ensure that each
evening his batteries are full and that he maximises the available
energy to stay aloft until the following dawn.
The construction uses today’s most advanced technologies and acts as a
catalyst for scientific research in the field of composite structures,
lightweight, so-called intelligent materials, and in ways of producing
and storing energy. These results will be utilised as much in the
construction of the plane, as later in various other applications
useful to society.

It is a long-term project, but each of its phases offers a number of
opportunities for communication:

feasibility study carried out in 2003 at the Swiss Federal Institute
of Technology, Lausanne
announcement of the challenge on 28th November 2003
first main sponsor signed in October 2004
conceptual design in 2004-2005
detailed design and assembly of the plane in 2006-2007
first test flights and full night flight in 2008
solar flights of several days’ duration from 2009:
crossing of a continent,
crossing the Atlantic,
round the world flight with one stop in each continent.

Scientific solutions
The technical teams have to manage the interaction and optimisation of
the different links in the propulsion chain, from the solar captors to
the propellers, by integrating the outside environment, which is
hostile to the materials, components and pilot, all the while
respecting the demands of weight and resistance. This is a high-flying
exercise.

In the same way that at the beginning of the past century, the
technology of the time enabled the development of motorised aviation,
today’s technologies are going to make possible the realisation of
solar-propelled airplanes. Although some of these machines have
already flown during the sunniest moments of the day, the present
challenge is to push back the boundaries much further, to enable
flying at night as easily as during the day. The crucial factor is the
harnessing of the sun during the day, so as to remain in the air as
well as storing enough energy for the night. In other words, to be
able to store the maximum of energy, while ensuring a very high
aerodynamic efficiency with a minimum of weight.

How can we achieve these sometimes conflicting objectives?
Energy:
First of all, we have to optimise all the different factors of
interaction, from the aerodynamic profile of the plane, the weight of
its structure and the elements in the chain of propulsion, through to
the pilot’s cockpit. The energy is stored during the day in lithium
batteries housed in the wings, and whose energy density must be close
to 200 Wh/kg, despite extreme external temperature conditions as low
as –60°C. The average power available from the sun is practically the
same as that available to the Wright brothers in 1903, when they
achieved their first flight for mankind (12 PS)! Success is dependant
upon the optimisation of efficiency and the reduction in weight.

The structu
The wingspan of the airplane must be about 80 metres, in order to
minimise the induced drag (aerodynamic losses) and maximise the
surface available for the solar cells. Dimensions of this scale imply
a higher weight and a greater susceptibility to turbulence. Therefore
we have to develop a concept of an ultra-light structure and
manufacture the wings using specifically adapted materials to contend
with the drastic weight demands. This concept is well beyond anything
achieved thus far.
Ultra thin and flexible solar cells will be integrated in the plane’s
wings, needing to survive the deformations and vibrations they will
encounter, encapsulated to guarantee a maximum efficiency in all
conditions, remembering that a typical range of temperature would vary
between -60 C and + 80 C, and including a good resistance to
ultra-violet rays.

The cockpit:
The cockpit will have a single seat, due to the still excessive weight
of the batteries. The pilot must be able to operate up to an altitude
of 12,000 metres, under hostile conditions of pressure and
temperature. The cockpit is therefore equipped with a pressurisation
system, oxygen circulation, CO2 elimination, as well as the
elimination of humidity generated by the human body which has the
tendency to transform itself into ice on the windows and cold
surfaces. These systems will also have to be extremely simple in terms
of their weight and energy consumption, in order not to compromise the
propulsion needs.


"NOTHING OF MAJOR SIGNIFICANCE EVER HAPPENED IN THE WORLD WITHOUT
EXAGGERATED HOPE." (Jules Verne)

("Larry Dighera" wrote)
Story he
http://www.businessweek.com/innovate/content/may2006/id20060508_074303.htm

Aircraft information:

http://www.solar-impulse.com/scripts/page7203.html

Objectives and main stages
The challenge consists in conceiving an airplane capable of taking off
autonomously, then climbing to an altitude of 12,000 metres, and
maintaining its flight for several days with no fuel, propelling itself by
means only of the solar cells mounted on its wings.


This should be setup like those x-country solar car races.

Like the National ["Reliability"] Air Tours (1925 - 1931) this isn't about
speed, but it should be about going someplace - even if it's just a three
day (three state) circular course at 40,000 ft.

I know, Around The World Flight is the eventual goal - and the real race.
That will be accomplished by an individual, whenever. Meanwhile we gather
....and race in smaller circles

I disagree with the self launch (autonomous) requirement for right now.
Let's cut 'em all some slack this first time out of the box! :-)

A White Knight/SpaceShipOne approach would be fine with me ...or balloons
....or whaterver works to get out teams up there. Once there the race begins.

"And they're off..."
"How can you tell?"

"Beer will be served for three days, with sales ending one hour before the
planned landing times. Enjoy the race."


Montblack
http://www.nationalairtour.org/
(1925-1931) + 2003 National Air Tour