Just like the eternal to and fro between civil engineers and architects to find the best balance between design and a physically viable structure, a constant discourse goes on between the Design and Structural Analysis teams at Solar Impulse. The difference is that they’re all engineers, so no need to fix wacky structures that can only exist in cartoons.

Everything that’s designed has a purpose but every part needs to fit in the greater scheme of things while also abiding to the strict lightweight guidelines. Led by Geri Piller, the Structural Analysis team consists of 4 engineers. The Design team has the concept, but it’s up to Geri’s team to decide which and how many materials to use for a given part in relation to the load that it must carry.

Geri once gave me a 101 Structural Analysis course (I would have certainly done better at reading a Chinese newspaper though), but I did manage to retain something: every material reacts differently to loads (for example, steel reacts to stress differently than carbon) and this is crucial when building a part.

For reasons of weight, the majority of HB-SIB’s structure is made out of carbon, a very peculiar material. Carbon is extremely resistant in the direction of its fibers, but extremely frail in the other. The Structural Analysis team has to decide in which direction the fibers must be placed, how thick each layer has to be and how many plies are needed. This results in complex manipulations with a specialized software (FEA finite element analysis) where the structural engineers manually input the characteristics they want and subsequently observe how the part reacts to the expected loads applied to it.

It’s not a linear process (it takes two to tango). It’s a constant back and forth between structural and design engineers, an ongoing discussion to reach perfection because, once the design and structure make the perfect match, the part is finally sent to the producer; a joint effort that gives birth to a new part. Because of the unique nature of this aircraft, every part is literally handmade. Consequently, some information can be lost in translation when transforming the software design into a manufactured part. That’s why every part needs to be tested thereafter; a crucial process Geri and his team actively engage in. Stay tuned for information about the Testing team coming soon on our blog!

In the photos: from left to right: Björn Müller, Stefan Pfammatter, Geri Piller and Dominik Dusek (adjacent), Geri Piller (bottom), FEA (top).

Follow the series here: "THE MAKING OF A SOLAR AIRPLANE"

Fighting the glacial wind, known as the bise in this part of Switzerland, Solar Impulse’s team, Swissport and Cargolux employees together were able to load HB-SIA’s disassembled parts into Cargolux’s mastodon Boeing-747. The aircraft is already on its way for the United States and is expected to land sometime around 12:30PM local San Francisco time on Thursday 21 February.

Never have I seen such a large aircraft up close and the relatively small size of the Payerne runway made the Jumbo Jet look even more disproportionate. Several curious onlookers were present last night to watch the beast gently touch the tarmac and maneuver into its loading position.

We had a chance to visit the 747’s insides, including the top deck with the cockpit and passenger seating. I was reassured, our engineers and technicians are in good hands: the seats looked comfortable and passengers even have access to a miniscule room with a bed. I couldn’t stop thinking about how pleasant it must be to do a transatlantic flight devoid of crying babies, irritatingly narrow seating areas (making you feel more like a sardine when the person in front of you gets too comfortable), and annoying lines to use the restroom after lunch. One small detail that might be missing is a smiley young flight attendant to serve them a hot meal. But then again, we don’t want our trio getting too distracted now, do we?

Farewell, Au Revoir and best of luck on your new adventure HB-SIA!

Tomorrow, 20 February 2013, Cargolux's impressive Boeing 747 (a.k.a. Jumbo Jet) will be landing at Payerne’s small military airfield. Scheduled to land between 4:45PM and 5PM, the loading will take place immediately thereafter with a departure the following day for Moffett Airfield at the Ames Research Center of NASA in San Francisco. Located at the heart of Silicon Valley, it’s the perfect place to start this year’s Across America mission.

Imagine, with the same wingspan as HB-SIA (64m) this aeronautical beast is 257 times the weight of Solar Impulse’s solar-powered airplane (1’600 kg vs. 412’770 kg)! The internal main deck will be stuffed with the dismantled HB-SIA and all the material needed to complete this spring/summer’s Across America mission, including the tools necessary for reassembly. This will leave enough room to squeeze in a few of our engineers and technicians somewhere between the fuselage and the tail boom for one, between the gondola crates and wing parts for the second and in front of the cockpit for the third…

Jokes aside; as much as we care about HB-SIA’s wellbeing, the three Solar Impulse team members have skillfully negotiated some fine business-style seating in the anterior part of the aircraft, avoiding an uncomfortable and frigid transatlantic flight to the faraway coast of California. They will be our watchdogs, ensuring the safety and handling requirements are followed during the unloading of this unique aircraft. 

Today, in the quaint city of Bern, which also happens to be Switzerland’s capital, the Swiss Federal Council reinforced its support of the Solar Impulse project.  

Thanks to this, Solar Impulse will continue to benefit from the hangars in Dübendorf (where HB-SIB is being built) and Payerne (where HB-SIA is currently housed and where the test flights of HB-SIB will occur). In the meantime, Switzerland’s affiliation to the project provides the ideal platform to showcase the Helvetian innovative and entrepreneurial spirit.

It’s not by chance that Solar Impulse took flight in this miniscule country at the heart of the Alps. Switzerland has always heavily invested in education and research and is currently home to some of the best laboratories, Universities and technologically innovative SMEs in the world. In fact, the project started thanks to a feasibility study done by the Swiss Polytechnic University in Lausanne (EPFL) while the aircraft was built using a number of materials researched, tested and manufactured within the Confederation’s borders.

The celebrated little white cross superimposed on a red square will once again proudly fly, this time through American skies. Let’s hope we’ll be able to break out, at least once, from the usual clichés of chocolates, cheeses and banks to show another side of this dynamic landlocked country...

The departure for the US is fast approaching! This week’s greatest challenge is finalizing the paperwork for transport and simulating the arrangement of the crates in the transporter’s main deck to identify the best and safest use of space.

Because the Jumbo Jet will be crossing borders and transporting goods that are considered dangerous (such as the lithium batteries and the motor gondolas), an additional batch of paperwork needs to be meticulously filled to avoid any delays or unnecessary checks during delivery. Although the risks are low, basic precautions need to be setup to avoid, for example, the batteries from catching fire or the magnetic force of the motor gondolas from potentially affecting the 747’s compass while in flight. 

Once the freight documentation is ready and the best arrangement of the Boeing’s greedy belly settled, it will only be a matter of finalizing the last details before everything is loaded and ready for departure. Check out this week’s time lapse video!

Less than three weeks to go before HB-SIA officially leave Swiss soil! 

EPISODE I: United States: A Mirage No More

EPISODE II: Playing with Cranes

Meanwhile…

Panels Up!

The Billabong High International School in the Maldives can enjoy the fruit of its efforts: the solar panels they’ve been waiting for are installed and over 50% of the school’s energy needs are now satisfied by the sun. Every 6 days, 1’000kg less of CO2 are being released into the atmosphere. 

On February 6^th, the 18 students involved in the project organized an inauguration ceremony to celebrate this incredible achievement. For this special event, they even prepared a short video showcasing their example to the world: everything is possible with enough willpower.

But the benefits of this adventure don’t end there. The enthusiasm the students have shown for this project have also made their professor, Mr. Odon Sanchez, very proud: they received the highest grades of the Cambridge exam in physics and the best ever recorded at Billabong!

The entire Solar Impulse team congratulates these young pioneers!

Thanks to loyal partners like Solvay, Schindler, Bayer MaterialScience and SwissRe Corporate Solutions, the dream to conquer new horizons is coming true. Their additional support allows Solar Impulse to achieve a flight mission which was not at all planned before we made the decision to rebuild the wing spar and to postpone the round-the-world flight from 2014 to 2015: crossing the United States from West Coast to East Coast this year! Other partners will probably join in the adventure.

Preparations for departure have increased in intensity. HB-SIA is now dismantled and the material needed for the mission is packed in big wooden crates, all of which will be loaded in a Boeing 747 and shipped to Moffett Airfield at the Ames Research Center of NASA in the heart of Silicon Valley; and from there, a new adventure begins…

For more information about the partnerships:

Solvay

Schindler 

Bayer MaterialScience

SwissRe Corporate Solutions